md

md4c.c (234850B)

---

 /* commit e9ff661ff818ee94a4a231958d9b6768dc6882c9 - mity/md4c repo
  * MD4C: Markdown parser for C
  * (http://github.com/mity/md4c)
  *
  * Copyright (c) 2016-2020 Martin Mitas
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  * IN THE SOFTWARE.
  */
 
 #include "md4c.h"
 
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 
 /*****************************
  ***  Miscellaneous Stuff  ***
  *****************************/
 
 #if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199409L
     /* C89/90 or old compilers in general may not understand "inline". */
     #if defined __GNUC__
         #define inline __inline__
     #elif defined _MSC_VER
         #define inline __inline
     #else
         #define inline
     #endif
 #endif
 
 /* Make the UTF-8 support the default. */
 #if !defined MD4C_USE_ASCII && !defined MD4C_USE_UTF8 && !defined MD4C_USE_UTF16
     #define MD4C_USE_UTF8
 #endif
 
 /* Magic for making wide literals with MD4C_USE_UTF16. */
 #ifdef _T
     #undef _T
 #endif
 #if defined MD4C_USE_UTF16
     #define _T(x)           L##x
 #else
     #define _T(x)           x
 #endif
 
 /* Misc. macros. */
 #define SIZEOF_ARRAY(a)     (sizeof(a) / sizeof(a[0]))
 
 #define STRINGIZE_(x)       #x
 #define STRINGIZE(x)        STRINGIZE_(x)
 
 #ifndef TRUE
     #define TRUE            1
     #define FALSE           0
 #endif
 
 #define MD_LOG(msg)                                                     \
     do {                                                                \
         if(ctx->parser.debug_log != NULL)                               \
             ctx->parser.debug_log((msg), ctx->userdata);                \
     } while(0)
 
 #ifdef DEBUG
     #define MD_ASSERT(cond)                                             \
             do {                                                        \
                 if(!(cond)) {                                           \
                     MD_LOG(__FILE__ ":" STRINGIZE(__LINE__) ": "        \
                            "Assertion '" STRINGIZE(cond) "' failed.");  \
                     exit(1);                                            \
                 }                                                       \
             } while(0)
 
     #define MD_UNREACHABLE()        MD_ASSERT(1 == 0)
 #else
     #ifdef __GNUC__
         #define MD_ASSERT(cond)     do { if(!(cond)) __builtin_unreachable(); } while(0)
         #define MD_UNREACHABLE()    do { __builtin_unreachable(); } while(0)
     #elif defined _MSC_VER  &&  _MSC_VER > 120
         #define MD_ASSERT(cond)     do { __assume(cond); } while(0)
         #define MD_UNREACHABLE()    do { __assume(0); } while(0)
     #else
         #define MD_ASSERT(cond)     do {} while(0)
         #define MD_UNREACHABLE()    do {} while(0)
     #endif
 #endif
 
 /* For falling through case labels in switch statements. */
 #if defined __clang__ && __clang_major__ >= 12
     #define MD_FALLTHROUGH()        __attribute__((fallthrough))
 #elif defined __GNUC__ && __GNUC__ >= 7
     #define MD_FALLTHROUGH()        __attribute__((fallthrough))
 #else
     #define MD_FALLTHROUGH()        ((void)0)
 #endif
 
 /* Suppress "unused parameter" warnings. */
 #define MD_UNUSED(x)                ((void)x)
 
 
 /************************
  ***  Internal Types  ***
  ************************/
 
 /* These are omnipresent so lets save some typing. */
 #define CHAR    MD_CHAR
 #define SZ      MD_SIZE
 #define OFF     MD_OFFSET
 
 typedef struct MD_MARK_tag MD_MARK;
 typedef struct MD_BLOCK_tag MD_BLOCK;
 typedef struct MD_CONTAINER_tag MD_CONTAINER;
 typedef struct MD_REF_DEF_tag MD_REF_DEF;
 
 
 /* During analyzes of inline marks, we need to manage some "mark chains",
  * of (yet unresolved) openers. This structure holds start/end of the chain.
  * The chain internals are then realized through MD_MARK::prev and ::next.
  */
 typedef struct MD_MARKCHAIN_tag MD_MARKCHAIN;
 struct MD_MARKCHAIN_tag {
     int head;   /* Index of first mark in the chain, or -1 if empty. */
     int tail;   /* Index of last mark in the chain, or -1 if empty. */
 };
 
 /* Context propagated through all the parsing. */
 typedef struct MD_CTX_tag MD_CTX;
 struct MD_CTX_tag {
     /* Immutable stuff (parameters of md_parse()). */
     const CHAR* text;
     SZ size;
     MD_PARSER parser;
     void* userdata;
 
     /* When this is true, it allows some optimizations. */
     int doc_ends_with_newline;
 
     /* Helper temporary growing buffer. */
     CHAR* buffer;
     unsigned alloc_buffer;
 
     /* Reference definitions. */
     MD_REF_DEF* ref_defs;
     int n_ref_defs;
     int alloc_ref_defs;
     void** ref_def_hashtable;
     int ref_def_hashtable_size;
 
     /* Stack of inline/span markers.
      * This is only used for parsing a single block contents but by storing it
      * here we may reuse the stack for subsequent blocks; i.e. we have fewer
      * (re)allocations. */
     MD_MARK* marks;
     int n_marks;
     int alloc_marks;
 
 #if defined MD4C_USE_UTF16
     char mark_char_map[128];
 #else
     char mark_char_map[256];
 #endif
 
     /* For resolving of inline spans. */
     MD_MARKCHAIN mark_chains[17];
 #define PTR_CHAIN                               (ctx->mark_chains[0])
 #define TABLECELLBOUNDARIES                     (ctx->mark_chains[1])
 #define ASTERISK_OPENERS_extraword_mod3_0       (ctx->mark_chains[2])
 #define ASTERISK_OPENERS_extraword_mod3_1       (ctx->mark_chains[3])
 #define ASTERISK_OPENERS_extraword_mod3_2       (ctx->mark_chains[4])
 #define ASTERISK_OPENERS_intraword_mod3_0       (ctx->mark_chains[5])
 #define ASTERISK_OPENERS_intraword_mod3_1       (ctx->mark_chains[6])
 #define ASTERISK_OPENERS_intraword_mod3_2       (ctx->mark_chains[7])
 #define UNDERSCORE_OPENERS                      (ctx->mark_chains[8])
 #define TILDE_OPENERS_1                         (ctx->mark_chains[9])
 #define TILDE_OPENERS_2                         (ctx->mark_chains[10])
 #define BRACKET_OPENERS                         (ctx->mark_chains[11])
 #define DOLLAR_OPENERS                          (ctx->mark_chains[12])
 #define FAINT_OPENERS                           (ctx->mark_chains[13])
 #define INVERSE_OPENERS                         (ctx->mark_chains[14])
 #define CONCEAL_OPENERS                         (ctx->mark_chains[15])
 #define BLINK_OPENERS                           (ctx->mark_chains[16])
 #define OPENERS_CHAIN_FIRST                     1
 #define OPENERS_CHAIN_LAST                      16
 
     int n_table_cell_boundaries;
 
     /* For resolving links. */
     int unresolved_link_head;
     int unresolved_link_tail;
 
     /* For resolving raw HTML. */
     OFF html_comment_horizon;
     OFF html_proc_instr_horizon;
     OFF html_decl_horizon;
     OFF html_cdata_horizon;
 
     /* For block analysis.
      * Notes:
      *   -- It holds MD_BLOCK as well as MD_LINE structures. After each
      *      MD_BLOCK, its (multiple) MD_LINE(s) follow.
      *   -- For MD_BLOCK_HTML and MD_BLOCK_CODE, MD_VERBATIMLINE(s) are used
      *      instead of MD_LINE(s).
      */
     void* block_bytes;
     MD_BLOCK* current_block;
     int n_block_bytes;
     int alloc_block_bytes;
 
     /* For container block analysis. */
     MD_CONTAINER* containers;
     int n_containers;
     int alloc_containers;
 
     /* Minimal indentation to call the block "indented code block". */
     unsigned code_indent_offset;
 
     /* Contextual info for line analysis. */
     SZ code_fence_length;   /* For checking closing fence length. */
     int html_block_type;    /* For checking closing raw HTML condition. */
     int last_line_has_list_loosening_effect;
     int last_list_item_starts_with_two_blank_lines;
 };
 
 enum MD_LINETYPE_tag {
     MD_LINE_BLANK,
     MD_LINE_HR,
     MD_LINE_ATXHEADER,
     MD_LINE_SETEXTHEADER,
     MD_LINE_SETEXTUNDERLINE,
     MD_LINE_INDENTEDCODE,
     MD_LINE_FENCEDCODE,
     MD_LINE_HTML,
     MD_LINE_TEXT,
     MD_LINE_TABLE,
     MD_LINE_TABLEUNDERLINE
 };
 typedef enum MD_LINETYPE_tag MD_LINETYPE;
 
 typedef struct MD_LINE_ANALYSIS_tag MD_LINE_ANALYSIS;
 struct MD_LINE_ANALYSIS_tag {
     MD_LINETYPE type    : 16;
     unsigned data       : 16;
     OFF beg;
     OFF end;
     unsigned indent;        /* Indentation level. */
 };
 
 typedef struct MD_LINE_tag MD_LINE;
 struct MD_LINE_tag {
     OFF beg;
     OFF end;
 };
 
 typedef struct MD_VERBATIMLINE_tag MD_VERBATIMLINE;
 struct MD_VERBATIMLINE_tag {
     OFF beg;
     OFF end;
     OFF indent;
 };
 
 
 /*****************
  ***  Helpers  ***
  *****************/
 
 /* Character accessors. */
 #define CH(off)                 (ctx->text[(off)])
 #define STR(off)                (ctx->text + (off))
 
 /* Character classification.
  * Note we assume ASCII compatibility of code points < 128 here. */
 #define ISIN_(ch, ch_min, ch_max)       ((ch_min) <= (unsigned)(ch) && (unsigned)(ch) <= (ch_max))
 #define ISANYOF_(ch, palette)           ((ch) != _T('\0')  &&  md_strchr((palette), (ch)) != NULL)
 #define ISANYOF2_(ch, ch1, ch2)         ((ch) == (ch1) || (ch) == (ch2))
 #define ISANYOF3_(ch, ch1, ch2, ch3)    ((ch) == (ch1) || (ch) == (ch2) || (ch) == (ch3))
 #define ISASCII_(ch)                    ((unsigned)(ch) <= 127)
 #define ISBLANK_(ch)                    (ISANYOF2_((ch), _T(' '), _T('\t')))
 #define ISNEWLINE_(ch)                  (ISANYOF2_((ch), _T('\r'), _T('\n')))
 #define ISWHITESPACE_(ch)               (ISBLANK_(ch) || ISANYOF2_((ch), _T('\v'), _T('\f')))
 #define ISCNTRL_(ch)                    ((unsigned)(ch) <= 31 || (unsigned)(ch) == 127)
 #define ISPUNCT_(ch)                    (ISIN_(ch, 33, 47) || ISIN_(ch, 58, 64) || ISIN_(ch, 91, 96) || ISIN_(ch, 123, 126))
 #define ISUPPER_(ch)                    (ISIN_(ch, _T('A'), _T('Z')))
 #define ISLOWER_(ch)                    (ISIN_(ch, _T('a'), _T('z')))
 #define ISALPHA_(ch)                    (ISUPPER_(ch) || ISLOWER_(ch))
 #define ISDIGIT_(ch)                    (ISIN_(ch, _T('0'), _T('9')))
 #define ISXDIGIT_(ch)                   (ISDIGIT_(ch) || ISIN_(ch, _T('A'), _T('F')) || ISIN_(ch, _T('a'), _T('f')))
 #define ISALNUM_(ch)                    (ISALPHA_(ch) || ISDIGIT_(ch))
 
 #define ISANYOF(off, palette)           ISANYOF_(CH(off), (palette))
 #define ISANYOF2(off, ch1, ch2)         ISANYOF2_(CH(off), (ch1), (ch2))
 #define ISANYOF3(off, ch1, ch2, ch3)    ISANYOF3_(CH(off), (ch1), (ch2), (ch3))
 #define ISASCII(off)                    ISASCII_(CH(off))
 #define ISBLANK(off)                    ISBLANK_(CH(off))
 #define ISNEWLINE(off)                  ISNEWLINE_(CH(off))
 #define ISWHITESPACE(off)               ISWHITESPACE_(CH(off))
 #define ISCNTRL(off)                    ISCNTRL_(CH(off))
 #define ISPUNCT(off)                    ISPUNCT_(CH(off))
 #define ISUPPER(off)                    ISUPPER_(CH(off))
 #define ISLOWER(off)                    ISLOWER_(CH(off))
 #define ISALPHA(off)                    ISALPHA_(CH(off))
 #define ISDIGIT(off)                    ISDIGIT_(CH(off))
 #define ISXDIGIT(off)                   ISXDIGIT_(CH(off))
 #define ISALNUM(off)                    ISALNUM_(CH(off))
 
 
 #if defined MD4C_USE_UTF16
     #define md_strchr wcschr
 #else
     #define md_strchr strchr
 #endif
 
 
 /* Case insensitive check of string equality. */
 static inline int
 md_ascii_case_eq(const CHAR* s1, const CHAR* s2, SZ n)
 {
     OFF i;
     for(i = 0; i < n; i++) {
         CHAR ch1 = s1[i];
         CHAR ch2 = s2[i];
 
         if(ISLOWER_(ch1))
             ch1 += ('A'-'a');
         if(ISLOWER_(ch2))
             ch2 += ('A'-'a');
         if(ch1 != ch2)
             return FALSE;
     }
     return TRUE;
 }
 
 static inline int
 md_ascii_eq(const CHAR* s1, const CHAR* s2, SZ n)
 {
     return memcmp(s1, s2, n * sizeof(CHAR)) == 0;
 }
 
 static int
 md_text_with_null_replacement(MD_CTX* ctx, MD_TEXTTYPE type, const CHAR* str, SZ size)
 {
     OFF off = 0;
     int ret = 0;
 
     while(1) {
         while(off < size  &&  str[off] != _T('\0'))
             off++;
 
         if(off > 0) {
             ret = ctx->parser.text(type, str, off, ctx->userdata);
             if(ret != 0)
                 return ret;
 
             str += off;
             size -= off;
             off = 0;
         }
 
         if(off >= size)
             return 0;
 
         ret = ctx->parser.text(MD_TEXT_NULLCHAR, _T(""), 1, ctx->userdata);
         if(ret != 0)
             return ret;
         off++;
     }
 }
 
 
 #define MD_CHECK(func)                                                      \
     do {                                                                    \
         ret = (func);                                                       \
         if(ret < 0)                                                         \
             goto abort;                                                     \
     } while(0)
 
 
 #define MD_TEMP_BUFFER(sz)                                                  \
     do {                                                                    \
         if(sz > ctx->alloc_buffer) {                                        \
             CHAR* new_buffer;                                               \
             SZ new_size = ((sz) + (sz) / 2 + 128) & ~127;                   \
                                                                             \
             new_buffer = realloc(ctx->buffer, new_size);                    \
             if(new_buffer == NULL) {                                        \
                 MD_LOG("realloc() failed.");                                \
                 ret = -1;                                                   \
                 goto abort;                                                 \
             }                                                               \
                                                                             \
             ctx->buffer = new_buffer;                                       \
             ctx->alloc_buffer = new_size;                                   \
         }                                                                   \
     } while(0)
 
 
 #define MD_ENTER_BLOCK(type, arg)                                           \
     do {                                                                    \
         ret = ctx->parser.enter_block((type), (arg), ctx->userdata);        \
         if(ret != 0) {                                                      \
             MD_LOG("Aborted from enter_block() callback.");                 \
             goto abort;                                                     \
         }                                                                   \
     } while(0)
 
 #define MD_LEAVE_BLOCK(type, arg)                                           \
     do {                                                                    \
         ret = ctx->parser.leave_block((type), (arg), ctx->userdata);        \
         if(ret != 0) {                                                      \
             MD_LOG("Aborted from leave_block() callback.");                 \
             goto abort;                                                     \
         }                                                                   \
     } while(0)
 
 #define MD_ENTER_SPAN(type, arg)                                            \
     do {                                                                    \
         ret = ctx->parser.enter_span((type), (arg), ctx->userdata);         \
         if(ret != 0) {                                                      \
             MD_LOG("Aborted from enter_span() callback.");                  \
             goto abort;                                                     \
         }                                                                   \
     } while(0)
 
 #define MD_LEAVE_SPAN(type, arg)                                            \
     do {                                                                    \
         ret = ctx->parser.leave_span((type), (arg), ctx->userdata);         \
         if(ret != 0) {                                                      \
             MD_LOG("Aborted from leave_span() callback.");                  \
             goto abort;                                                     \
         }                                                                   \
     } while(0)
 
 #define MD_TEXT(type, str, size)                                            \
     do {                                                                    \
         if(size > 0) {                                                      \
             ret = ctx->parser.text((type), (str), (size), ctx->userdata);   \
             if(ret != 0) {                                                  \
                 MD_LOG("Aborted from text() callback.");                    \
                 goto abort;                                                 \
             }                                                               \
         }                                                                   \
     } while(0)
 
 #define MD_TEXT_INSECURE(type, str, size)                                   \
     do {                                                                    \
         if(size > 0) {                                                      \
             ret = md_text_with_null_replacement(ctx, type, str, size);      \
             if(ret != 0) {                                                  \
                 MD_LOG("Aborted from text() callback.");                    \
                 goto abort;                                                 \
             }                                                               \
         }                                                                   \
     } while(0)
 
 
 /* If the offset falls into a gap between line, we return the following
  * line. */
 static const MD_LINE*
 md_lookup_line(OFF off, const MD_LINE* lines, int n_lines)
 {
     int lo, hi;
     int pivot;
     const MD_LINE* line;
 
     lo = 0;
     hi = n_lines - 1;
     while(lo <= hi) {
         pivot = (lo + hi) / 2;
         line = &lines[pivot];
 
         if(off < line->beg) {
             hi = pivot - 1;
             if(hi < 0  ||  lines[hi].end <= off)
                 return line;
         } else if(off > line->end) {
             lo = pivot + 1;
         } else {
             return line;
         }
     }
 
     return NULL;
 }
 
 
 /*************************
  ***  Unicode Support  ***
  *************************/
 
 typedef struct MD_UNICODE_FOLD_INFO_tag MD_UNICODE_FOLD_INFO;
 struct MD_UNICODE_FOLD_INFO_tag {
     unsigned codepoints[3];
     unsigned n_codepoints;
 };
 
 
 #if defined MD4C_USE_UTF16 || defined MD4C_USE_UTF8
     /* Binary search over sorted "map" of codepoints. Consecutive sequences
      * of codepoints may be encoded in the map by just using the
      * (MIN_CODEPOINT | 0x40000000) and (MAX_CODEPOINT | 0x80000000).
      *
      * Returns index of the found record in the map (in the case of ranges,
      * the minimal value is used); or -1 on failure. */
     static int
     md_unicode_bsearch__(unsigned codepoint, const unsigned* map, size_t map_size)
     {
         int beg, end;
         int pivot_beg, pivot_end;
 
         beg = 0;
         end = (int) map_size-1;
         while(beg <= end) {
             /* Pivot may be a range, not just a single value. */
             pivot_beg = pivot_end = (beg + end) / 2;
             if(map[pivot_end] & 0x40000000)
                 pivot_end++;
             if(map[pivot_beg] & 0x80000000)
                 pivot_beg--;
 
             if(codepoint < (map[pivot_beg] & 0x00ffffff))
                 end = pivot_beg - 1;
             else if(codepoint > (map[pivot_end] & 0x00ffffff))
                 beg = pivot_end + 1;
             else
                 return pivot_beg;
         }
 
         return -1;
     }
 
     static int
     md_is_unicode_whitespace__(unsigned codepoint)
     {
 #define R(cp_min, cp_max)   ((cp_min) | 0x40000000), ((cp_max) | 0x80000000)
 #define S(cp)               (cp)
         /* Unicode "Zs" category.
          * (generated by scripts/build_whitespace_map.py) */
         static const unsigned WHITESPACE_MAP[] = {
             S(0x0020), S(0x00a0), S(0x1680), R(0x2000,0x200a), S(0x202f), S(0x205f), S(0x3000)
         };
 #undef R
 #undef S
 
         /* The ASCII ones are the most frequently used ones, also CommonMark
          * specification requests few more in this range. */
         if(codepoint <= 0x7f)
             return ISWHITESPACE_(codepoint);
 
         return (md_unicode_bsearch__(codepoint, WHITESPACE_MAP, SIZEOF_ARRAY(WHITESPACE_MAP)) >= 0);
     }
 
     static int
     md_is_unicode_punct__(unsigned codepoint)
     {
 #define R(cp_min, cp_max)   ((cp_min) | 0x40000000), ((cp_max) | 0x80000000)
 #define S(cp)               (cp)
         /* Unicode "Pc", "Pd", "Pe", "Pf", "Pi", "Po", "Ps" categories.
          * (generated by scripts/build_punct_map.py) */
         static const unsigned PUNCT_MAP[] = {
             R(0x0021,0x0023), R(0x0025,0x002a), R(0x002c,0x002f), R(0x003a,0x003b), R(0x003f,0x0040),
             R(0x005b,0x005d), S(0x005f), S(0x007b), S(0x007d), S(0x00a1), S(0x00a7), S(0x00ab), R(0x00b6,0x00b7),
             S(0x00bb), S(0x00bf), S(0x037e), S(0x0387), R(0x055a,0x055f), R(0x0589,0x058a), S(0x05be), S(0x05c0),
             S(0x05c3), S(0x05c6), R(0x05f3,0x05f4), R(0x0609,0x060a), R(0x060c,0x060d), S(0x061b), R(0x061e,0x061f),
             R(0x066a,0x066d), S(0x06d4), R(0x0700,0x070d), R(0x07f7,0x07f9), R(0x0830,0x083e), S(0x085e),
             R(0x0964,0x0965), S(0x0970), S(0x09fd), S(0x0a76), S(0x0af0), S(0x0c77), S(0x0c84), S(0x0df4), S(0x0e4f),
             R(0x0e5a,0x0e5b), R(0x0f04,0x0f12), S(0x0f14), R(0x0f3a,0x0f3d), S(0x0f85), R(0x0fd0,0x0fd4),
             R(0x0fd9,0x0fda), R(0x104a,0x104f), S(0x10fb), R(0x1360,0x1368), S(0x1400), S(0x166e), R(0x169b,0x169c),
             R(0x16eb,0x16ed), R(0x1735,0x1736), R(0x17d4,0x17d6), R(0x17d8,0x17da), R(0x1800,0x180a),
             R(0x1944,0x1945), R(0x1a1e,0x1a1f), R(0x1aa0,0x1aa6), R(0x1aa8,0x1aad), R(0x1b5a,0x1b60),
             R(0x1bfc,0x1bff), R(0x1c3b,0x1c3f), R(0x1c7e,0x1c7f), R(0x1cc0,0x1cc7), S(0x1cd3), R(0x2010,0x2027),
             R(0x2030,0x2043), R(0x2045,0x2051), R(0x2053,0x205e), R(0x207d,0x207e), R(0x208d,0x208e),
             R(0x2308,0x230b), R(0x2329,0x232a), R(0x2768,0x2775), R(0x27c5,0x27c6), R(0x27e6,0x27ef),
             R(0x2983,0x2998), R(0x29d8,0x29db), R(0x29fc,0x29fd), R(0x2cf9,0x2cfc), R(0x2cfe,0x2cff), S(0x2d70),
             R(0x2e00,0x2e2e), R(0x2e30,0x2e4f), S(0x2e52), R(0x3001,0x3003), R(0x3008,0x3011), R(0x3014,0x301f),
             S(0x3030), S(0x303d), S(0x30a0), S(0x30fb), R(0xa4fe,0xa4ff), R(0xa60d,0xa60f), S(0xa673), S(0xa67e),
             R(0xa6f2,0xa6f7), R(0xa874,0xa877), R(0xa8ce,0xa8cf), R(0xa8f8,0xa8fa), S(0xa8fc), R(0xa92e,0xa92f),
             S(0xa95f), R(0xa9c1,0xa9cd), R(0xa9de,0xa9df), R(0xaa5c,0xaa5f), R(0xaade,0xaadf), R(0xaaf0,0xaaf1),
             S(0xabeb), R(0xfd3e,0xfd3f), R(0xfe10,0xfe19), R(0xfe30,0xfe52), R(0xfe54,0xfe61), S(0xfe63), S(0xfe68),
             R(0xfe6a,0xfe6b), R(0xff01,0xff03), R(0xff05,0xff0a), R(0xff0c,0xff0f), R(0xff1a,0xff1b),
             R(0xff1f,0xff20), R(0xff3b,0xff3d), S(0xff3f), S(0xff5b), S(0xff5d), R(0xff5f,0xff65), R(0x10100,0x10102),
             S(0x1039f), S(0x103d0), S(0x1056f), S(0x10857), S(0x1091f), S(0x1093f), R(0x10a50,0x10a58), S(0x10a7f),
             R(0x10af0,0x10af6), R(0x10b39,0x10b3f), R(0x10b99,0x10b9c), S(0x10ead), R(0x10f55,0x10f59),
             R(0x11047,0x1104d), R(0x110bb,0x110bc), R(0x110be,0x110c1), R(0x11140,0x11143), R(0x11174,0x11175),
             R(0x111c5,0x111c8), S(0x111cd), S(0x111db), R(0x111dd,0x111df), R(0x11238,0x1123d), S(0x112a9),
             R(0x1144b,0x1144f), R(0x1145a,0x1145b), S(0x1145d), S(0x114c6), R(0x115c1,0x115d7), R(0x11641,0x11643),
             R(0x11660,0x1166c), R(0x1173c,0x1173e), S(0x1183b), R(0x11944,0x11946), S(0x119e2), R(0x11a3f,0x11a46),
             R(0x11a9a,0x11a9c), R(0x11a9e,0x11aa2), R(0x11c41,0x11c45), R(0x11c70,0x11c71), R(0x11ef7,0x11ef8),
             S(0x11fff), R(0x12470,0x12474), R(0x16a6e,0x16a6f), S(0x16af5), R(0x16b37,0x16b3b), S(0x16b44),
             R(0x16e97,0x16e9a), S(0x16fe2), S(0x1bc9f), R(0x1da87,0x1da8b), R(0x1e95e,0x1e95f)
         };
 #undef R
 #undef S
 
         /* The ASCII ones are the most frequently used ones, also CommonMark
          * specification requests few more in this range. */
         if(codepoint <= 0x7f)
             return ISPUNCT_(codepoint);
 
         return (md_unicode_bsearch__(codepoint, PUNCT_MAP, SIZEOF_ARRAY(PUNCT_MAP)) >= 0);
     }
 
     static void
     md_get_unicode_fold_info(unsigned codepoint, MD_UNICODE_FOLD_INFO* info)
     {
 #define R(cp_min, cp_max)   ((cp_min) | 0x40000000), ((cp_max) | 0x80000000)
 #define S(cp)               (cp)
         /* Unicode "Pc", "Pd", "Pe", "Pf", "Pi", "Po", "Ps" categories.
          * (generated by scripts/build_folding_map.py) */
         static const unsigned FOLD_MAP_1[] = {
             R(0x0041,0x005a), S(0x00b5), R(0x00c0,0x00d6), R(0x00d8,0x00de), R(0x0100,0x012e), R(0x0132,0x0136),
             R(0x0139,0x0147), R(0x014a,0x0176), S(0x0178), R(0x0179,0x017d), S(0x017f), S(0x0181), S(0x0182),
             S(0x0184), S(0x0186), S(0x0187), S(0x0189), S(0x018a), S(0x018b), S(0x018e), S(0x018f), S(0x0190),
             S(0x0191), S(0x0193), S(0x0194), S(0x0196), S(0x0197), S(0x0198), S(0x019c), S(0x019d), S(0x019f),
             R(0x01a0,0x01a4), S(0x01a6), S(0x01a7), S(0x01a9), S(0x01ac), S(0x01ae), S(0x01af), S(0x01b1), S(0x01b2),
             S(0x01b3), S(0x01b5), S(0x01b7), S(0x01b8), S(0x01bc), S(0x01c4), S(0x01c5), S(0x01c7), S(0x01c8),
             S(0x01ca), R(0x01cb,0x01db), R(0x01de,0x01ee), S(0x01f1), S(0x01f2), S(0x01f4), S(0x01f6), S(0x01f7),
             R(0x01f8,0x021e), S(0x0220), R(0x0222,0x0232), S(0x023a), S(0x023b), S(0x023d), S(0x023e), S(0x0241),
             S(0x0243), S(0x0244), S(0x0245), R(0x0246,0x024e), S(0x0345), S(0x0370), S(0x0372), S(0x0376), S(0x037f),
             S(0x0386), R(0x0388,0x038a), S(0x038c), S(0x038e), S(0x038f), R(0x0391,0x03a1), R(0x03a3,0x03ab),
             S(0x03c2), S(0x03cf), S(0x03d0), S(0x03d1), S(0x03d5), S(0x03d6), R(0x03d8,0x03ee), S(0x03f0), S(0x03f1),
             S(0x03f4), S(0x03f5), S(0x03f7), S(0x03f9), S(0x03fa), R(0x03fd,0x03ff), R(0x0400,0x040f),
             R(0x0410,0x042f), R(0x0460,0x0480), R(0x048a,0x04be), S(0x04c0), R(0x04c1,0x04cd), R(0x04d0,0x052e),
             R(0x0531,0x0556), R(0x10a0,0x10c5), S(0x10c7), S(0x10cd), R(0x13f8,0x13fd), S(0x1c80), S(0x1c81),
             S(0x1c82), S(0x1c83), S(0x1c84), S(0x1c85), S(0x1c86), S(0x1c87), S(0x1c88), R(0x1c90,0x1cba),
             R(0x1cbd,0x1cbf), R(0x1e00,0x1e94), S(0x1e9b), R(0x1ea0,0x1efe), R(0x1f08,0x1f0f), R(0x1f18,0x1f1d),
             R(0x1f28,0x1f2f), R(0x1f38,0x1f3f), R(0x1f48,0x1f4d), S(0x1f59), S(0x1f5b), S(0x1f5d), S(0x1f5f),
             R(0x1f68,0x1f6f), S(0x1fb8), S(0x1fb9), S(0x1fba), S(0x1fbb), S(0x1fbe), R(0x1fc8,0x1fcb), S(0x1fd8),
             S(0x1fd9), S(0x1fda), S(0x1fdb), S(0x1fe8), S(0x1fe9), S(0x1fea), S(0x1feb), S(0x1fec), S(0x1ff8),
             S(0x1ff9), S(0x1ffa), S(0x1ffb), S(0x2126), S(0x212a), S(0x212b), S(0x2132), R(0x2160,0x216f), S(0x2183),
             R(0x24b6,0x24cf), R(0x2c00,0x2c2e), S(0x2c60), S(0x2c62), S(0x2c63), S(0x2c64), R(0x2c67,0x2c6b),
             S(0x2c6d), S(0x2c6e), S(0x2c6f), S(0x2c70), S(0x2c72), S(0x2c75), S(0x2c7e), S(0x2c7f), R(0x2c80,0x2ce2),
             S(0x2ceb), S(0x2ced), S(0x2cf2), R(0xa640,0xa66c), R(0xa680,0xa69a), R(0xa722,0xa72e), R(0xa732,0xa76e),
             S(0xa779), S(0xa77b), S(0xa77d), R(0xa77e,0xa786), S(0xa78b), S(0xa78d), S(0xa790), S(0xa792),
             R(0xa796,0xa7a8), S(0xa7aa), S(0xa7ab), S(0xa7ac), S(0xa7ad), S(0xa7ae), S(0xa7b0), S(0xa7b1), S(0xa7b2),
             S(0xa7b3), R(0xa7b4,0xa7be), S(0xa7c2), S(0xa7c4), S(0xa7c5), S(0xa7c6), S(0xa7c7), S(0xa7c9), S(0xa7f5),
             R(0xab70,0xabbf), R(0xff21,0xff3a), R(0x10400,0x10427), R(0x104b0,0x104d3), R(0x10c80,0x10cb2),
             R(0x118a0,0x118bf), R(0x16e40,0x16e5f), R(0x1e900,0x1e921)
         };
         static const unsigned FOLD_MAP_1_DATA[] = {
             0x0061, 0x007a, 0x03bc, 0x00e0, 0x00f6, 0x00f8, 0x00fe, 0x0101, 0x012f, 0x0133, 0x0137, 0x013a, 0x0148,
             0x014b, 0x0177, 0x00ff, 0x017a, 0x017e, 0x0073, 0x0253, 0x0183, 0x0185, 0x0254, 0x0188, 0x0256, 0x0257,
             0x018c, 0x01dd, 0x0259, 0x025b, 0x0192, 0x0260, 0x0263, 0x0269, 0x0268, 0x0199, 0x026f, 0x0272, 0x0275,
             0x01a1, 0x01a5, 0x0280, 0x01a8, 0x0283, 0x01ad, 0x0288, 0x01b0, 0x028a, 0x028b, 0x01b4, 0x01b6, 0x0292,
             0x01b9, 0x01bd, 0x01c6, 0x01c6, 0x01c9, 0x01c9, 0x01cc, 0x01cc, 0x01dc, 0x01df, 0x01ef, 0x01f3, 0x01f3,
             0x01f5, 0x0195, 0x01bf, 0x01f9, 0x021f, 0x019e, 0x0223, 0x0233, 0x2c65, 0x023c, 0x019a, 0x2c66, 0x0242,
             0x0180, 0x0289, 0x028c, 0x0247, 0x024f, 0x03b9, 0x0371, 0x0373, 0x0377, 0x03f3, 0x03ac, 0x03ad, 0x03af,
             0x03cc, 0x03cd, 0x03ce, 0x03b1, 0x03c1, 0x03c3, 0x03cb, 0x03c3, 0x03d7, 0x03b2, 0x03b8, 0x03c6, 0x03c0,
             0x03d9, 0x03ef, 0x03ba, 0x03c1, 0x03b8, 0x03b5, 0x03f8, 0x03f2, 0x03fb, 0x037b, 0x037d, 0x0450, 0x045f,
             0x0430, 0x044f, 0x0461, 0x0481, 0x048b, 0x04bf, 0x04cf, 0x04c2, 0x04ce, 0x04d1, 0x052f, 0x0561, 0x0586,
             0x2d00, 0x2d25, 0x2d27, 0x2d2d, 0x13f0, 0x13f5, 0x0432, 0x0434, 0x043e, 0x0441, 0x0442, 0x0442, 0x044a,
             0x0463, 0xa64b, 0x10d0, 0x10fa, 0x10fd, 0x10ff, 0x1e01, 0x1e95, 0x1e61, 0x1ea1, 0x1eff, 0x1f00, 0x1f07,
             0x1f10, 0x1f15, 0x1f20, 0x1f27, 0x1f30, 0x1f37, 0x1f40, 0x1f45, 0x1f51, 0x1f53, 0x1f55, 0x1f57, 0x1f60,
             0x1f67, 0x1fb0, 0x1fb1, 0x1f70, 0x1f71, 0x03b9, 0x1f72, 0x1f75, 0x1fd0, 0x1fd1, 0x1f76, 0x1f77, 0x1fe0,
             0x1fe1, 0x1f7a, 0x1f7b, 0x1fe5, 0x1f78, 0x1f79, 0x1f7c, 0x1f7d, 0x03c9, 0x006b, 0x00e5, 0x214e, 0x2170,
             0x217f, 0x2184, 0x24d0, 0x24e9, 0x2c30, 0x2c5e, 0x2c61, 0x026b, 0x1d7d, 0x027d, 0x2c68, 0x2c6c, 0x0251,
             0x0271, 0x0250, 0x0252, 0x2c73, 0x2c76, 0x023f, 0x0240, 0x2c81, 0x2ce3, 0x2cec, 0x2cee, 0x2cf3, 0xa641,
             0xa66d, 0xa681, 0xa69b, 0xa723, 0xa72f, 0xa733, 0xa76f, 0xa77a, 0xa77c, 0x1d79, 0xa77f, 0xa787, 0xa78c,
             0x0265, 0xa791, 0xa793, 0xa797, 0xa7a9, 0x0266, 0x025c, 0x0261, 0x026c, 0x026a, 0x029e, 0x0287, 0x029d,
             0xab53, 0xa7b5, 0xa7bf, 0xa7c3, 0xa794, 0x0282, 0x1d8e, 0xa7c8, 0xa7ca, 0xa7f6, 0x13a0, 0x13ef, 0xff41,
             0xff5a, 0x10428, 0x1044f, 0x104d8, 0x104fb, 0x10cc0, 0x10cf2, 0x118c0, 0x118df, 0x16e60, 0x16e7f, 0x1e922,
             0x1e943
         };
         static const unsigned FOLD_MAP_2[] = {
             S(0x00df), S(0x0130), S(0x0149), S(0x01f0), S(0x0587), S(0x1e96), S(0x1e97), S(0x1e98), S(0x1e99),
             S(0x1e9a), S(0x1e9e), S(0x1f50), R(0x1f80,0x1f87), R(0x1f88,0x1f8f), R(0x1f90,0x1f97), R(0x1f98,0x1f9f),
             R(0x1fa0,0x1fa7), R(0x1fa8,0x1faf), S(0x1fb2), S(0x1fb3), S(0x1fb4), S(0x1fb6), S(0x1fbc), S(0x1fc2),
             S(0x1fc3), S(0x1fc4), S(0x1fc6), S(0x1fcc), S(0x1fd6), S(0x1fe4), S(0x1fe6), S(0x1ff2), S(0x1ff3),
             S(0x1ff4), S(0x1ff6), S(0x1ffc), S(0xfb00), S(0xfb01), S(0xfb02), S(0xfb05), S(0xfb06), S(0xfb13),
             S(0xfb14), S(0xfb15), S(0xfb16), S(0xfb17)
         };
         static const unsigned FOLD_MAP_2_DATA[] = {
             0x0073,0x0073, 0x0069,0x0307, 0x02bc,0x006e, 0x006a,0x030c, 0x0565,0x0582, 0x0068,0x0331, 0x0074,0x0308,
             0x0077,0x030a, 0x0079,0x030a, 0x0061,0x02be, 0x0073,0x0073, 0x03c5,0x0313, 0x1f00,0x03b9, 0x1f07,0x03b9,
             0x1f00,0x03b9, 0x1f07,0x03b9, 0x1f20,0x03b9, 0x1f27,0x03b9, 0x1f20,0x03b9, 0x1f27,0x03b9, 0x1f60,0x03b9,
             0x1f67,0x03b9, 0x1f60,0x03b9, 0x1f67,0x03b9, 0x1f70,0x03b9, 0x03b1,0x03b9, 0x03ac,0x03b9, 0x03b1,0x0342,
             0x03b1,0x03b9, 0x1f74,0x03b9, 0x03b7,0x03b9, 0x03ae,0x03b9, 0x03b7,0x0342, 0x03b7,0x03b9, 0x03b9,0x0342,
             0x03c1,0x0313, 0x03c5,0x0342, 0x1f7c,0x03b9, 0x03c9,0x03b9, 0x03ce,0x03b9, 0x03c9,0x0342, 0x03c9,0x03b9,
             0x0066,0x0066, 0x0066,0x0069, 0x0066,0x006c, 0x0073,0x0074, 0x0073,0x0074, 0x0574,0x0576, 0x0574,0x0565,
             0x0574,0x056b, 0x057e,0x0576, 0x0574,0x056d
         };
         static const unsigned FOLD_MAP_3[] = {
             S(0x0390), S(0x03b0), S(0x1f52), S(0x1f54), S(0x1f56), S(0x1fb7), S(0x1fc7), S(0x1fd2), S(0x1fd3),
             S(0x1fd7), S(0x1fe2), S(0x1fe3), S(0x1fe7), S(0x1ff7), S(0xfb03), S(0xfb04)
         };
         static const unsigned FOLD_MAP_3_DATA[] = {
             0x03b9,0x0308,0x0301, 0x03c5,0x0308,0x0301, 0x03c5,0x0313,0x0300, 0x03c5,0x0313,0x0301,
             0x03c5,0x0313,0x0342, 0x03b1,0x0342,0x03b9, 0x03b7,0x0342,0x03b9, 0x03b9,0x0308,0x0300,
             0x03b9,0x0308,0x0301, 0x03b9,0x0308,0x0342, 0x03c5,0x0308,0x0300, 0x03c5,0x0308,0x0301,
             0x03c5,0x0308,0x0342, 0x03c9,0x0342,0x03b9, 0x0066,0x0066,0x0069, 0x0066,0x0066,0x006c
         };
 #undef R
 #undef S
         static const struct {
             const unsigned* map;
             const unsigned* data;
             size_t map_size;
             unsigned n_codepoints;
         } FOLD_MAP_LIST[] = {
             { FOLD_MAP_1, FOLD_MAP_1_DATA, SIZEOF_ARRAY(FOLD_MAP_1), 1 },
             { FOLD_MAP_2, FOLD_MAP_2_DATA, SIZEOF_ARRAY(FOLD_MAP_2), 2 },
             { FOLD_MAP_3, FOLD_MAP_3_DATA, SIZEOF_ARRAY(FOLD_MAP_3), 3 }
         };
 
         int i;
 
         /* Fast path for ASCII characters. */
         if(codepoint <= 0x7f) {
             info->codepoints[0] = codepoint;
             if(ISUPPER_(codepoint))
                 info->codepoints[0] += 'a' - 'A';
             info->n_codepoints = 1;
             return;
         }
 
         /* Try to locate the codepoint in any of the maps. */
         for(i = 0; i < (int) SIZEOF_ARRAY(FOLD_MAP_LIST); i++) {
             int index;
 
             index = md_unicode_bsearch__(codepoint, FOLD_MAP_LIST[i].map, FOLD_MAP_LIST[i].map_size);
             if(index >= 0) {
                 /* Found the mapping. */
                 unsigned n_codepoints = FOLD_MAP_LIST[i].n_codepoints;
                 const unsigned* map = FOLD_MAP_LIST[i].map;
                 const unsigned* codepoints = FOLD_MAP_LIST[i].data + (index * n_codepoints);
 
                 memcpy(info->codepoints, codepoints, sizeof(unsigned) * n_codepoints);
                 info->n_codepoints = n_codepoints;
 
                 if(FOLD_MAP_LIST[i].map[index] != codepoint) {
                     /* The found mapping maps whole range of codepoints,
                      * i.e. we have to offset info->codepoints[0] accordingly. */
                     if((map[index] & 0x00ffffff)+1 == codepoints[0]) {
                         /* Alternating type of the range. */
                         info->codepoints[0] = codepoint + ((codepoint & 0x1) == (map[index] & 0x1) ? 1 : 0);
                     } else {
                         /* Range to range kind of mapping. */
                         info->codepoints[0] += (codepoint - (map[index] & 0x00ffffff));
                     }
                 }
 
                 return;
             }
         }
 
         /* No mapping found. Map the codepoint to itself. */
         info->codepoints[0] = codepoint;
         info->n_codepoints = 1;
     }
 #endif
 
 
 #if defined MD4C_USE_UTF16
     #define IS_UTF16_SURROGATE_HI(word)     (((WORD)(word) & 0xfc00) == 0xd800)
     #define IS_UTF16_SURROGATE_LO(word)     (((WORD)(word) & 0xfc00) == 0xdc00)
     #define UTF16_DECODE_SURROGATE(hi, lo)  (0x10000 + ((((unsigned)(hi) & 0x3ff) << 10) | (((unsigned)(lo) & 0x3ff) << 0)))
 
     static unsigned
     md_decode_utf16le__(const CHAR* str, SZ str_size, SZ* p_size)
     {
         if(IS_UTF16_SURROGATE_HI(str[0])) {
             if(1 < str_size && IS_UTF16_SURROGATE_LO(str[1])) {
                 if(p_size != NULL)
                     *p_size = 2;
                 return UTF16_DECODE_SURROGATE(str[0], str[1]);
             }
         }
 
         if(p_size != NULL)
             *p_size = 1;
         return str[0];
     }
 
     static unsigned
     md_decode_utf16le_before__(MD_CTX* ctx, OFF off)
     {
         if(off > 2 && IS_UTF16_SURROGATE_HI(CH(off-2)) && IS_UTF16_SURROGATE_LO(CH(off-1)))
             return UTF16_DECODE_SURROGATE(CH(off-2), CH(off-1));
 
         return CH(off);
     }
 
     /* No whitespace uses surrogates, so no decoding needed here. */
     #define ISUNICODEWHITESPACE_(codepoint) md_is_unicode_whitespace__(codepoint)
     #define ISUNICODEWHITESPACE(off)        md_is_unicode_whitespace__(CH(off))
     #define ISUNICODEWHITESPACEBEFORE(off)  md_is_unicode_whitespace__(CH((off)-1))
 
     #define ISUNICODEPUNCT(off)             md_is_unicode_punct__(md_decode_utf16le__(STR(off), ctx->size - (off), NULL))
     #define ISUNICODEPUNCTBEFORE(off)       md_is_unicode_punct__(md_decode_utf16le_before__(ctx, off))
 
     static inline int
     md_decode_unicode(const CHAR* str, OFF off, SZ str_size, SZ* p_char_size)
     {
         return md_decode_utf16le__(str+off, str_size-off, p_char_size);
     }
 #elif defined MD4C_USE_UTF8
     #define IS_UTF8_LEAD1(byte)     ((unsigned char)(byte) <= 0x7f)
     #define IS_UTF8_LEAD2(byte)     (((unsigned char)(byte) & 0xe0) == 0xc0)
     #define IS_UTF8_LEAD3(byte)     (((unsigned char)(byte) & 0xf0) == 0xe0)
     #define IS_UTF8_LEAD4(byte)     (((unsigned char)(byte) & 0xf8) == 0xf0)
     #define IS_UTF8_TAIL(byte)      (((unsigned char)(byte) & 0xc0) == 0x80)
 
     static unsigned
     md_decode_utf8__(const CHAR* str, SZ str_size, SZ* p_size)
     {
         if(!IS_UTF8_LEAD1(str[0])) {
             if(IS_UTF8_LEAD2(str[0])) {
                 if(1 < str_size && IS_UTF8_TAIL(str[1])) {
                     if(p_size != NULL)
                         *p_size = 2;
 
                     return (((unsigned int)str[0] & 0x1f) << 6) |
                            (((unsigned int)str[1] & 0x3f) << 0);
                 }
             } else if(IS_UTF8_LEAD3(str[0])) {
                 if(2 < str_size && IS_UTF8_TAIL(str[1]) && IS_UTF8_TAIL(str[2])) {
                     if(p_size != NULL)
                         *p_size = 3;
 
                     return (((unsigned int)str[0] & 0x0f) << 12) |
                            (((unsigned int)str[1] & 0x3f) << 6) |
                            (((unsigned int)str[2] & 0x3f) << 0);
                 }
             } else if(IS_UTF8_LEAD4(str[0])) {
                 if(3 < str_size && IS_UTF8_TAIL(str[1]) && IS_UTF8_TAIL(str[2]) && IS_UTF8_TAIL(str[3])) {
                     if(p_size != NULL)
                         *p_size = 4;
 
                     return (((unsigned int)str[0] & 0x07) << 18) |
                            (((unsigned int)str[1] & 0x3f) << 12) |
                            (((unsigned int)str[2] & 0x3f) << 6) |
                            (((unsigned int)str[3] & 0x3f) << 0);
                 }
             }
         }
 
         if(p_size != NULL)
             *p_size = 1;
         return (unsigned) str[0];
     }
 
     static unsigned
     md_decode_utf8_before__(MD_CTX* ctx, OFF off)
     {
         if(!IS_UTF8_LEAD1(CH(off-1))) {
             if(off > 1 && IS_UTF8_LEAD2(CH(off-2)) && IS_UTF8_TAIL(CH(off-1)))
                 return (((unsigned int)CH(off-2) & 0x1f) << 6) |
                        (((unsigned int)CH(off-1) & 0x3f) << 0);
 
             if(off > 2 && IS_UTF8_LEAD3(CH(off-3)) && IS_UTF8_TAIL(CH(off-2)) && IS_UTF8_TAIL(CH(off-1)))
                 return (((unsigned int)CH(off-3) & 0x0f) << 12) |
                        (((unsigned int)CH(off-2) & 0x3f) << 6) |
                        (((unsigned int)CH(off-1) & 0x3f) << 0);
 
             if(off > 3 && IS_UTF8_LEAD4(CH(off-4)) && IS_UTF8_TAIL(CH(off-3)) && IS_UTF8_TAIL(CH(off-2)) && IS_UTF8_TAIL(CH(off-1)))
                 return (((unsigned int)CH(off-4) & 0x07) << 18) |
                        (((unsigned int)CH(off-3) & 0x3f) << 12) |
                        (((unsigned int)CH(off-2) & 0x3f) << 6) |
                        (((unsigned int)CH(off-1) & 0x3f) << 0);
         }
 
         return (unsigned) CH(off-1);
     }
 
     #define ISUNICODEWHITESPACE_(codepoint) md_is_unicode_whitespace__(codepoint)
     #define ISUNICODEWHITESPACE(off)        md_is_unicode_whitespace__(md_decode_utf8__(STR(off), ctx->size - (off), NULL))
     #define ISUNICODEWHITESPACEBEFORE(off)  md_is_unicode_whitespace__(md_decode_utf8_before__(ctx, off))
 
     #define ISUNICODEPUNCT(off)             md_is_unicode_punct__(md_decode_utf8__(STR(off), ctx->size - (off), NULL))
     #define ISUNICODEPUNCTBEFORE(off)       md_is_unicode_punct__(md_decode_utf8_before__(ctx, off))
 
     static inline unsigned
     md_decode_unicode(const CHAR* str, OFF off, SZ str_size, SZ* p_char_size)
     {
         return md_decode_utf8__(str+off, str_size-off, p_char_size);
     }
 #else
     #define ISUNICODEWHITESPACE_(codepoint) ISWHITESPACE_(codepoint)
     #define ISUNICODEWHITESPACE(off)        ISWHITESPACE(off)
     #define ISUNICODEWHITESPACEBEFORE(off)  ISWHITESPACE((off)-1)
 
     #define ISUNICODEPUNCT(off)             ISPUNCT(off)
     #define ISUNICODEPUNCTBEFORE(off)       ISPUNCT((off)-1)
 
     static inline void
     md_get_unicode_fold_info(unsigned codepoint, MD_UNICODE_FOLD_INFO* info)
     {
         info->codepoints[0] = codepoint;
         if(ISUPPER_(codepoint))
             info->codepoints[0] += 'a' - 'A';
         info->n_codepoints = 1;
     }
 
     static inline unsigned
     md_decode_unicode(const CHAR* str, OFF off, SZ str_size, SZ* p_size)
     {
         *p_size = 1;
         return (unsigned) str[off];
     }
 #endif
 
 
 /*************************************
  ***  Helper string manipulations  ***
  *************************************/
 
 /* Fill buffer with copy of the string between 'beg' and 'end' but replace any
  * line breaks with given replacement character.
  *
  * NOTE: Caller is responsible to make sure the buffer is large enough.
  * (Given the output is always shorter then input, (end - beg) is good idea
  * what the caller should allocate.)
  */
 static void
 md_merge_lines(MD_CTX* ctx, OFF beg, OFF end, const MD_LINE* lines, int n_lines,
                CHAR line_break_replacement_char, CHAR* buffer, SZ* p_size)
 {
     CHAR* ptr = buffer;
     int line_index = 0;
     OFF off = beg;
 
     MD_UNUSED(n_lines);
 
     while(1) {
         const MD_LINE* line = &lines[line_index];
         OFF line_end = line->end;
         if(end < line_end)
             line_end = end;
 
         while(off < line_end) {
             *ptr = CH(off);
             ptr++;
             off++;
         }
 
         if(off >= end) {
             *p_size = (MD_SIZE)(ptr - buffer);
             return;
         }
 
         *ptr = line_break_replacement_char;
         ptr++;
 
         line_index++;
         off = lines[line_index].beg;
     }
 }
 
 /* Wrapper of md_merge_lines() which allocates new buffer for the output string.
  */
 static int
 md_merge_lines_alloc(MD_CTX* ctx, OFF beg, OFF end, const MD_LINE* lines, int n_lines,
                     CHAR line_break_replacement_char, CHAR** p_str, SZ* p_size)
 {
     CHAR* buffer;
 
     buffer = (CHAR*) malloc(sizeof(CHAR) * (end - beg));
     if(buffer == NULL) {
         MD_LOG("malloc() failed.");
         return -1;
     }
 
     md_merge_lines(ctx, beg, end, lines, n_lines,
                 line_break_replacement_char, buffer, p_size);
 
     *p_str = buffer;
     return 0;
 }
 
 static OFF
 md_skip_unicode_whitespace(const CHAR* label, OFF off, SZ size)
 {
     SZ char_size;
     unsigned codepoint;
 
     while(off < size) {
         codepoint = md_decode_unicode(label, off, size, &char_size);
         if(!ISUNICODEWHITESPACE_(codepoint)  &&  !ISNEWLINE_(label[off]))
             break;
         off += char_size;
     }
 
     return off;
 }
 
 
 /******************************
  ***  Recognizing raw HTML  ***
  ******************************/
 
 /* md_is_html_tag() may be called when processing inlines (inline raw HTML)
  * or when breaking document to blocks (checking for start of HTML block type 7).
  *
  * When breaking document to blocks, we do not yet know line boundaries, but
  * in that case the whole tag has to live on a single line. We distinguish this
  * by n_lines == 0.
  */
 static int
 md_is_html_tag(MD_CTX* ctx, const MD_LINE* lines, int n_lines, OFF beg, OFF max_end, OFF* p_end)
 {
     int attr_state;
     OFF off = beg;
     OFF line_end = (n_lines > 0) ? lines[0].end : ctx->size;
     int i = 0;
 
     MD_ASSERT(CH(beg) == _T('<'));
 
     if(off + 1 >= line_end)
         return FALSE;
     off++;
 
     /* For parsing attributes, we need a little state automaton below.
      * State -1: no attributes are allowed.
      * State 0: attribute could follow after some whitespace.
      * State 1: after a whitespace (attribute name may follow).
      * State 2: after attribute name ('=' MAY follow).
      * State 3: after '=' (value specification MUST follow).
      * State 41: in middle of unquoted attribute value.
      * State 42: in middle of single-quoted attribute value.
      * State 43: in middle of double-quoted attribute value.
      */
     attr_state = 0;
 
     if(CH(off) == _T('/')) {
         /* Closer tag "</ ... >". No attributes may be present. */
         attr_state = -1;
         off++;
     }
 
     /* Tag name */
     if(off >= line_end  ||  !ISALPHA(off))
         return FALSE;
     off++;
     while(off < line_end  &&  (ISALNUM(off)  ||  CH(off) == _T('-')))
         off++;
 
     /* (Optional) attributes (if not closer), (optional) '/' (if not closer)
      * and final '>'. */
     while(1) {
         while(off < line_end  &&  !ISNEWLINE(off)) {
             if(attr_state > 40) {
                 if(attr_state == 41 && (ISBLANK(off) || ISANYOF(off, _T("\"'=<>`")))) {
                     attr_state = 0;
                     off--;  /* Put the char back for re-inspection in the new state. */
                 } else if(attr_state == 42 && CH(off) == _T('\'')) {
                     attr_state = 0;
                 } else if(attr_state == 43 && CH(off) == _T('"')) {
                     attr_state = 0;
                 }
                 off++;
             } else if(ISWHITESPACE(off)) {
                 if(attr_state == 0)
                     attr_state = 1;
                 off++;
             } else if(attr_state <= 2 && CH(off) == _T('>')) {
                 /* End. */
                 goto done;
             } else if(attr_state <= 2 && CH(off) == _T('/') && off+1 < line_end && CH(off+1) == _T('>')) {
                 /* End with digraph '/>' */
                 off++;
                 goto done;
             } else if((attr_state == 1 || attr_state == 2) && (ISALPHA(off) || CH(off) == _T('_') || CH(off) == _T(':'))) {
                 off++;
                 /* Attribute name */
                 while(off < line_end && (ISALNUM(off) || ISANYOF(off, _T("_.:-"))))
                     off++;
                 attr_state = 2;
             } else if(attr_state == 2 && CH(off) == _T('=')) {
                 /* Attribute assignment sign */
                 off++;
                 attr_state = 3;
             } else if(attr_state == 3) {
                 /* Expecting start of attribute value. */
                 if(CH(off) == _T('"'))
                     attr_state = 43;
                 else if(CH(off) == _T('\''))
                     attr_state = 42;
                 else if(!ISANYOF(off, _T("\"'=<>`"))  &&  !ISNEWLINE(off))
                     attr_state = 41;
                 else
                     return FALSE;
                 off++;
             } else {
                 /* Anything unexpected. */
                 return FALSE;
             }
         }
 
         /* We have to be on a single line. See definition of start condition
          * of HTML block, type 7. */
         if(n_lines == 0)
             return FALSE;
 
         i++;
         if(i >= n_lines)
             return FALSE;
 
         off = lines[i].beg;
         line_end = lines[i].end;
 
         if(attr_state == 0  ||  attr_state == 41)
             attr_state = 1;
 
         if(off >= max_end)
             return FALSE;
     }
 
 done:
     if(off >= max_end)
         return FALSE;
 
     *p_end = off+1;
     return TRUE;
 }
 
 static int
 md_scan_for_html_closer(MD_CTX* ctx, const MD_CHAR* str, MD_SIZE len,
                         const MD_LINE* lines, int n_lines,
                         OFF beg, OFF max_end, OFF* p_end,
                         OFF* p_scan_horizon)
 {
     OFF off = beg;
     int i = 0;
 
     if(off < *p_scan_horizon  &&  *p_scan_horizon >= max_end - len) {
         /* We have already scanned the range up to the max_end so we know
          * there is nothing to see. */
         return FALSE;
     }
 
     while(TRUE) {
         while(off + len <= lines[i].end  &&  off + len <= max_end) {
             if(md_ascii_eq(STR(off), str, len)) {
                 /* Success. */
                 *p_end = off + len;
                 return TRUE;
             }
             off++;
         }
 
         i++;
         if(off >= max_end  ||  i >= n_lines) {
             /* Failure. */
             *p_scan_horizon = off;
             return FALSE;
         }
 
         off = lines[i].beg;
     }
 }
 
 static int
 md_is_html_comment(MD_CTX* ctx, const MD_LINE* lines, int n_lines, OFF beg, OFF max_end, OFF* p_end)
 {
     OFF off = beg;
 
     MD_ASSERT(CH(beg) == _T('<'));
 
     if(off + 4 >= lines[0].end)
         return FALSE;
     if(CH(off+1) != _T('!')  ||  CH(off+2) != _T('-')  ||  CH(off+3) != _T('-'))
         return FALSE;
     off += 4;
 
     /* ">" and "->" must not follow the opening. */
     if(off < lines[0].end  &&  CH(off) == _T('>'))
         return FALSE;
     if(off+1 < lines[0].end  &&  CH(off) == _T('-')  &&  CH(off+1) == _T('>'))
         return FALSE;
 
     /* HTML comment must not contain "--", so we scan just for "--" instead
      * of "-->" and verify manually that '>' follows. */
     if(md_scan_for_html_closer(ctx, _T("--"), 2,
                 lines, n_lines, off, max_end, p_end, &ctx->html_comment_horizon))
     {
         if(*p_end < max_end  &&  CH(*p_end) == _T('>')) {
             *p_end = *p_end + 1;
             return TRUE;
         }
     }
 
     return FALSE;
 }
 
 static int
 md_is_html_processing_instruction(MD_CTX* ctx, const MD_LINE* lines, int n_lines, OFF beg, OFF max_end, OFF* p_end)
 {
     OFF off = beg;
 
     if(off + 2 >= lines[0].end)
         return FALSE;
     if(CH(off+1) != _T('?'))
         return FALSE;
     off += 2;
 
     return md_scan_for_html_closer(ctx, _T("?>"), 2,
                 lines, n_lines, off, max_end, p_end, &ctx->html_proc_instr_horizon);
 }
 
 static int
 md_is_html_declaration(MD_CTX* ctx, const MD_LINE* lines, int n_lines, OFF beg, OFF max_end, OFF* p_end)
 {
     OFF off = beg;
 
     if(off + 2 >= lines[0].end)
         return FALSE;
     if(CH(off+1) != _T('!'))
         return FALSE;
     off += 2;
 
     /* Declaration name. */
     if(off >= lines[0].end  ||  !ISALPHA(off))
         return FALSE;
     off++;
     while(off < lines[0].end  &&  ISALPHA(off))
         off++;
     if(off < lines[0].end  &&  !ISWHITESPACE(off))
         return FALSE;
 
     return md_scan_for_html_closer(ctx, _T(">"), 1,
                 lines, n_lines, off, max_end, p_end, &ctx->html_decl_horizon);
 }
 
 static int
 md_is_html_cdata(MD_CTX* ctx, const MD_LINE* lines, int n_lines, OFF beg, OFF max_end, OFF* p_end)
 {
     static const CHAR open_str[] = _T("<![CDATA[");
     static const SZ open_size = SIZEOF_ARRAY(open_str) - 1;
 
     OFF off = beg;
 
     if(off + open_size >= lines[0].end)
         return FALSE;
     if(memcmp(STR(off), open_str, open_size) != 0)
         return FALSE;
     off += open_size;
 
     if(lines[n_lines-1].end < max_end)
         max_end = lines[n_lines-1].end - 2;
 
     return md_scan_for_html_closer(ctx, _T("]]>"), 3,
                 lines, n_lines, off, max_end, p_end, &ctx->html_cdata_horizon);
 }
 
 static int
 md_is_html_any(MD_CTX* ctx, const MD_LINE* lines, int n_lines, OFF beg, OFF max_end, OFF* p_end)
 {
     MD_ASSERT(CH(beg) == _T('<'));
     return (md_is_html_tag(ctx, lines, n_lines, beg, max_end, p_end)  ||
             md_is_html_comment(ctx, lines, n_lines, beg, max_end, p_end)  ||
             md_is_html_processing_instruction(ctx, lines, n_lines, beg, max_end, p_end)  ||
             md_is_html_declaration(ctx, lines, n_lines, beg, max_end, p_end)  ||
             md_is_html_cdata(ctx, lines, n_lines, beg, max_end, p_end));
 }
 
 
 /****************************
  ***  Recognizing Entity  ***
  ****************************/
 
 static int
 md_is_hex_entity_contents(MD_CTX* ctx, const CHAR* text, OFF beg, OFF max_end, OFF* p_end)
 {
     OFF off = beg;
     MD_UNUSED(ctx);
 
     while(off < max_end  &&  ISXDIGIT_(text[off])  &&  off - beg <= 8)
         off++;
 
     if(1 <= off - beg  &&  off - beg <= 6) {
         *p_end = off;
         return TRUE;
     } else {
         return FALSE;
     }
 }
 
 static int
 md_is_dec_entity_contents(MD_CTX* ctx, const CHAR* text, OFF beg, OFF max_end, OFF* p_end)
 {
     OFF off = beg;
     MD_UNUSED(ctx);
 
     while(off < max_end  &&  ISDIGIT_(text[off])  &&  off - beg <= 8)
         off++;
 
     if(1 <= off - beg  &&  off - beg <= 7) {
         *p_end = off;
         return TRUE;
     } else {
         return FALSE;
     }
 }
 
 static int
 md_is_named_entity_contents(MD_CTX* ctx, const CHAR* text, OFF beg, OFF max_end, OFF* p_end)
 {
     OFF off = beg;
     MD_UNUSED(ctx);
 
     if(off < max_end  &&  ISALPHA_(text[off]))
         off++;
     else
         return FALSE;
 
     while(off < max_end  &&  ISALNUM_(text[off])  &&  off - beg <= 48)
         off++;
 
     if(2 <= off - beg  &&  off - beg <= 48) {
         *p_end = off;
         return TRUE;
     } else {
         return FALSE;
     }
 }
 
 static int
 md_is_entity_str(MD_CTX* ctx, const CHAR* text, OFF beg, OFF max_end, OFF* p_end)
 {
     int is_contents;
     OFF off = beg;
 
     MD_ASSERT(text[off] == _T('&'));
     off++;
 
     if(off+2 < max_end  &&  text[off] == _T('#')  &&  (text[off+1] == _T('x') || text[off+1] == _T('X')))
         is_contents = md_is_hex_entity_contents(ctx, text, off+2, max_end, &off);
     else if(off+1 < max_end  &&  text[off] == _T('#'))
         is_contents = md_is_dec_entity_contents(ctx, text, off+1, max_end, &off);
     else
         is_contents = md_is_named_entity_contents(ctx, text, off, max_end, &off);
 
     if(is_contents  &&  off < max_end  &&  text[off] == _T(';')) {
         *p_end = off+1;
         return TRUE;
     } else {
         return FALSE;
     }
 }
 
 static inline int
 md_is_entity(MD_CTX* ctx, OFF beg, OFF max_end, OFF* p_end)
 {
     return md_is_entity_str(ctx, ctx->text, beg, max_end, p_end);
 }
 
 
 /******************************
  ***  Attribute Management  ***
  ******************************/
 
 typedef struct MD_ATTRIBUTE_BUILD_tag MD_ATTRIBUTE_BUILD;
 struct MD_ATTRIBUTE_BUILD_tag {
     CHAR* text;
     MD_TEXTTYPE* substr_types;
     OFF* substr_offsets;
     int substr_count;
     int substr_alloc;
     MD_TEXTTYPE trivial_types[1];
     OFF trivial_offsets[2];
 };
 
 
 #define MD_BUILD_ATTR_NO_ESCAPES    0x0001
 
 static int
 md_build_attr_append_substr(MD_CTX* ctx, MD_ATTRIBUTE_BUILD* build,
                             MD_TEXTTYPE type, OFF off)
 {
     if(build->substr_count >= build->substr_alloc) {
         MD_TEXTTYPE* new_substr_types;
         OFF* new_substr_offsets;
 
         build->substr_alloc = (build->substr_alloc > 0
                 ? build->substr_alloc + build->substr_alloc / 2
                 : 8);
         new_substr_types = (MD_TEXTTYPE*) realloc(build->substr_types,
                                     build->substr_alloc * sizeof(MD_TEXTTYPE));
         if(new_substr_types == NULL) {
             MD_LOG("realloc() failed.");
             return -1;
         }
         /* Note +1 to reserve space for final offset (== raw_size). */
         new_substr_offsets = (OFF*) realloc(build->substr_offsets,
                                     (build->substr_alloc+1) * sizeof(OFF));
         if(new_substr_offsets == NULL) {
             MD_LOG("realloc() failed.");
             free(new_substr_types);
             return -1;
         }
 
         build->substr_types = new_substr_types;
         build->substr_offsets = new_substr_offsets;
     }
 
     build->substr_types[build->substr_count] = type;
     build->substr_offsets[build->substr_count] = off;
     build->substr_count++;
     return 0;
 }
 
 static void
 md_free_attribute(MD_CTX* ctx, MD_ATTRIBUTE_BUILD* build)
 {
     MD_UNUSED(ctx);
 
     if(build->substr_alloc > 0) {
         free(build->text);
         free(build->substr_types);
         free(build->substr_offsets);
     }
 }
 
 static int
 md_build_attribute(MD_CTX* ctx, const CHAR* raw_text, SZ raw_size,
                    unsigned flags, MD_ATTRIBUTE* attr, MD_ATTRIBUTE_BUILD* build)
 {
     OFF raw_off, off;
     int is_trivial;
     int ret = 0;
 
     memset(build, 0, sizeof(MD_ATTRIBUTE_BUILD));
 
     /* If there is no backslash and no ampersand, build trivial attribute
      * without any malloc(). */
     is_trivial = TRUE;
     for(raw_off = 0; raw_off < raw_size; raw_off++) {
         if(ISANYOF3_(raw_text[raw_off], _T('\\'), _T('&'), _T('\0'))) {
             is_trivial = FALSE;
             break;
         }
     }
 
     if(is_trivial) {
         build->text = (CHAR*) (raw_size ? raw_text : NULL);
         build->substr_types = build->trivial_types;
         build->substr_offsets = build->trivial_offsets;
         build->substr_count = 1;
         build->substr_alloc = 0;
         build->trivial_types[0] = MD_TEXT_NORMAL;
         build->trivial_offsets[0] = 0;
         build->trivial_offsets[1] = raw_size;
         off = raw_size;
     } else {
         build->text = (CHAR*) malloc(raw_size * sizeof(CHAR));
         if(build->text == NULL) {
             MD_LOG("malloc() failed.");
             goto abort;
         }
 
         raw_off = 0;
         off = 0;
 
         while(raw_off < raw_size) {
             if(raw_text[raw_off] == _T('\0')) {
                 MD_CHECK(md_build_attr_append_substr(ctx, build, MD_TEXT_NULLCHAR, off));
                 memcpy(build->text + off, raw_text + raw_off, 1);
                 off++;
                 raw_off++;
                 continue;
             }
 
             if(raw_text[raw_off] == _T('&')) {
                 OFF ent_end;
 
                 if(md_is_entity_str(ctx, raw_text, raw_off, raw_size, &ent_end)) {
                     MD_CHECK(md_build_attr_append_substr(ctx, build, MD_TEXT_ENTITY, off));
                     memcpy(build->text + off, raw_text + raw_off, ent_end - raw_off);
                     off += ent_end - raw_off;
                     raw_off = ent_end;
                     continue;
                 }
             }
 
             if(build->substr_count == 0  ||  build->substr_types[build->substr_count-1] != MD_TEXT_NORMAL)
                 MD_CHECK(md_build_attr_append_substr(ctx, build, MD_TEXT_NORMAL, off));
 
             if(!(flags & MD_BUILD_ATTR_NO_ESCAPES)  &&
                raw_text[raw_off] == _T('\\')  &&  raw_off+1 < raw_size  &&
                (ISPUNCT_(raw_text[raw_off+1]) || ISNEWLINE_(raw_text[raw_off+1])))
                 raw_off++;
 
             build->text[off++] = raw_text[raw_off++];
         }
         build->substr_offsets[build->substr_count] = off;
     }
 
     attr->text = build->text;
     attr->size = off;
     attr->substr_offsets = build->substr_offsets;
     attr->substr_types = build->substr_types;
     return 0;
 
 abort:
     md_free_attribute(ctx, build);
     return -1;
 }
 
 
 /*********************************************
  ***  Dictionary of Reference Definitions  ***
  *********************************************/
 
 #define MD_FNV1A_BASE       2166136261U
 #define MD_FNV1A_PRIME      16777619U
 
 static inline unsigned
 md_fnv1a(unsigned base, const void* data, size_t n)
 {
     const unsigned char* buf = (const unsigned char*) data;
     unsigned hash = base;
     size_t i;
 
     for(i = 0; i < n; i++) {
         hash ^= buf[i];
         hash *= MD_FNV1A_PRIME;
     }
 
     return hash;
 }
 
 
 struct MD_REF_DEF_tag {
     CHAR* label;
     CHAR* title;
     unsigned hash;
     SZ label_size;
     SZ title_size;
     OFF dest_beg;
     OFF dest_end;
     unsigned char label_needs_free : 1;
     unsigned char title_needs_free : 1;
 };
 
 /* Label equivalence is quite complicated with regards to whitespace and case
  * folding. This complicates computing a hash of it as well as direct comparison
  * of two labels. */
 
 static unsigned
 md_link_label_hash(const CHAR* label, SZ size)
 {
     unsigned hash = MD_FNV1A_BASE;
     OFF off;
     unsigned codepoint;
     int is_whitespace = FALSE;
 
     off = md_skip_unicode_whitespace(label, 0, size);
     while(off < size) {
         SZ char_size;
 
         codepoint = md_decode_unicode(label, off, size, &char_size);
         is_whitespace = ISUNICODEWHITESPACE_(codepoint) || ISNEWLINE_(label[off]);
 
         if(is_whitespace) {
             codepoint = ' ';
             hash = md_fnv1a(hash, &codepoint, sizeof(unsigned));
             off = md_skip_unicode_whitespace(label, off, size);
         } else {
             MD_UNICODE_FOLD_INFO fold_info;
 
             md_get_unicode_fold_info(codepoint, &fold_info);
             hash = md_fnv1a(hash, fold_info.codepoints, fold_info.n_codepoints * sizeof(unsigned));
             off += char_size;
         }
     }
 
     return hash;
 }
 
 static OFF
 md_link_label_cmp_load_fold_info(const CHAR* label, OFF off, SZ size,
                                  MD_UNICODE_FOLD_INFO* fold_info)
 {
     unsigned codepoint;
     SZ char_size;
 
     if(off >= size) {
         /* Treat end of a link label as a whitespace. */
         goto whitespace;
     }
 
     codepoint = md_decode_unicode(label, off, size, &char_size);
     off += char_size;
     if(ISUNICODEWHITESPACE_(codepoint)) {
         /* Treat all whitespace as equivalent */
         goto whitespace;
     }
 
     /* Get real folding info. */
     md_get_unicode_fold_info(codepoint, fold_info);
     return off;
 
 whitespace:
     fold_info->codepoints[0] = _T(' ');
     fold_info->n_codepoints = 1;
     return md_skip_unicode_whitespace(label, off, size);
 }
 
 static int
 md_link_label_cmp(const CHAR* a_label, SZ a_size, const CHAR* b_label, SZ b_size)
 {
     OFF a_off;
     OFF b_off;
     MD_UNICODE_FOLD_INFO a_fi = { { 0 }, 0 };
     MD_UNICODE_FOLD_INFO b_fi = { { 0 }, 0 };
     OFF a_fi_off = 0;
     OFF b_fi_off = 0;
     int cmp;
 
     a_off = md_skip_unicode_whitespace(a_label, 0, a_size);
     b_off = md_skip_unicode_whitespace(b_label, 0, b_size);
     while(a_off < a_size || a_fi_off < a_fi.n_codepoints ||
           b_off < b_size || b_fi_off < b_fi.n_codepoints)
     {
         /* If needed, load fold info for next char. */
         if(a_fi_off >= a_fi.n_codepoints) {
             a_fi_off = 0;
             a_off = md_link_label_cmp_load_fold_info(a_label, a_off, a_size, &a_fi);
         }
         if(b_fi_off >= b_fi.n_codepoints) {
             b_fi_off = 0;
             b_off = md_link_label_cmp_load_fold_info(b_label, b_off, b_size, &b_fi);
         }
 
         cmp = b_fi.codepoints[b_fi_off] - a_fi.codepoints[a_fi_off];
         if(cmp != 0)
             return cmp;
 
         a_fi_off++;
         b_fi_off++;
     }
 
     return 0;
 }
 
 typedef struct MD_REF_DEF_LIST_tag MD_REF_DEF_LIST;
 struct MD_REF_DEF_LIST_tag {
     int n_ref_defs;
     int alloc_ref_defs;
     MD_REF_DEF* ref_defs[];  /* Valid items always  point into ctx->ref_defs[] */
 };
 
 static int
 md_ref_def_cmp(const void* a, const void* b)
 {
     const MD_REF_DEF* a_ref = *(const MD_REF_DEF**)a;
     const MD_REF_DEF* b_ref = *(const MD_REF_DEF**)b;
 
     if(a_ref->hash < b_ref->hash)
         return -1;
     else if(a_ref->hash > b_ref->hash)
         return +1;
     else
         return md_link_label_cmp(a_ref->label, a_ref->label_size, b_ref->label, b_ref->label_size);
 }
 
 static int
 md_ref_def_cmp_for_sort(const void* a, const void* b)
 {
     int cmp;
 
     cmp = md_ref_def_cmp(a, b);
 
     /* Ensure stability of the sorting. */
     if(cmp == 0) {
         const MD_REF_DEF* a_ref = *(const MD_REF_DEF**)a;
         const MD_REF_DEF* b_ref = *(const MD_REF_DEF**)b;
 
         if(a_ref < b_ref)
             cmp = -1;
         else if(a_ref > b_ref)
             cmp = +1;
         else
             cmp = 0;
     }
 
     return cmp;
 }
 
 static int
 md_build_ref_def_hashtable(MD_CTX* ctx)
 {
     int i, j;
 
     if(ctx->n_ref_defs == 0)
         return 0;
 
     ctx->ref_def_hashtable_size = (ctx->n_ref_defs * 5) / 4;
     ctx->ref_def_hashtable = malloc(ctx->ref_def_hashtable_size * sizeof(void*));
     if(ctx->ref_def_hashtable == NULL) {
         MD_LOG("malloc() failed.");
         goto abort;
     }
     memset(ctx->ref_def_hashtable, 0, ctx->ref_def_hashtable_size * sizeof(void*));
 
     /* Each member of ctx->ref_def_hashtable[] can be:
      *  -- NULL,
      *  -- pointer to the MD_REF_DEF in ctx->ref_defs[], or
      *  -- pointer to a MD_REF_DEF_LIST, which holds multiple pointers to
      *     such MD_REF_DEFs.
      */
     for(i = 0; i < ctx->n_ref_defs; i++) {
         MD_REF_DEF* def = &ctx->ref_defs[i];
         void* bucket;
         MD_REF_DEF_LIST* list;
 
         def->hash = md_link_label_hash(def->label, def->label_size);
         bucket = ctx->ref_def_hashtable[def->hash % ctx->ref_def_hashtable_size];
 
         if(bucket == NULL) {
             /* The bucket is empty. Make it just point to the def. */
             ctx->ref_def_hashtable[def->hash % ctx->ref_def_hashtable_size] = def;
             continue;
         }
 
         if(ctx->ref_defs <= (MD_REF_DEF*) bucket  &&  (MD_REF_DEF*) bucket < ctx->ref_defs + ctx->n_ref_defs) {
             /* The bucket already contains one ref. def. Lets see whether it
              * is the same label (ref. def. duplicate) or different one
              * (hash conflict). */
             MD_REF_DEF* old_def = (MD_REF_DEF*) bucket;
 
             if(md_link_label_cmp(def->label, def->label_size, old_def->label, old_def->label_size) == 0) {
                 /* Duplicate label: Ignore this ref. def. */
                 continue;
             }
 
             /* Make the bucket complex, i.e. able to hold more ref. defs. */
             list = (MD_REF_DEF_LIST*) malloc(sizeof(MD_REF_DEF_LIST) + 2 * sizeof(MD_REF_DEF*));
             if(list == NULL) {
                 MD_LOG("malloc() failed.");
                 goto abort;
             }
             list->ref_defs[0] = old_def;
             list->ref_defs[1] = def;
             list->n_ref_defs = 2;
             list->alloc_ref_defs = 2;
             ctx->ref_def_hashtable[def->hash % ctx->ref_def_hashtable_size] = list;
             continue;
         }
 
         /* Append the def to the complex bucket list.
          *
          * Note in this case we ignore potential duplicates to avoid expensive
          * iterating over the complex bucket. Below, we revisit all the complex
          * buckets and handle it more cheaply after the complex bucket contents
          * is sorted. */
         list = (MD_REF_DEF_LIST*) bucket;
         if(list->n_ref_defs >= list->alloc_ref_defs) {
             int alloc_ref_defs = list->alloc_ref_defs + list->alloc_ref_defs / 2;
             MD_REF_DEF_LIST* list_tmp = (MD_REF_DEF_LIST*) realloc(list,
                         sizeof(MD_REF_DEF_LIST) + alloc_ref_defs * sizeof(MD_REF_DEF*));
             if(list_tmp == NULL) {
                 MD_LOG("realloc() failed.");
                 goto abort;
             }
             list = list_tmp;
             list->alloc_ref_defs = alloc_ref_defs;
             ctx->ref_def_hashtable[def->hash % ctx->ref_def_hashtable_size] = list;
         }
 
         list->ref_defs[list->n_ref_defs] = def;
         list->n_ref_defs++;
     }
 
     /* Sort the complex buckets so we can use bsearch() with them. */
     for(i = 0; i < ctx->ref_def_hashtable_size; i++) {
         void* bucket = ctx->ref_def_hashtable[i];
         MD_REF_DEF_LIST* list;
 
         if(bucket == NULL)
             continue;
         if(ctx->ref_defs <= (MD_REF_DEF*) bucket  &&  (MD_REF_DEF*) bucket < ctx->ref_defs + ctx->n_ref_defs)
             continue;
 
         list = (MD_REF_DEF_LIST*) bucket;
         qsort(list->ref_defs, list->n_ref_defs, sizeof(MD_REF_DEF*), md_ref_def_cmp_for_sort);
 
         /* Disable all duplicates in the complex bucket by forcing all such
          * records to point to the 1st such ref. def. I.e. no matter which
          * record is found during the lookup, it will always point to the right
          * ref. def. in ctx->ref_defs[]. */
         for(j = 1; j < list->n_ref_defs; j++) {
             if(md_ref_def_cmp(&list->ref_defs[j-1], &list->ref_defs[j]) == 0)
                 list->ref_defs[j] = list->ref_defs[j-1];
         }
     }
 
     return 0;
 
 abort:
     return -1;
 }
 
 static void
 md_free_ref_def_hashtable(MD_CTX* ctx)
 {
     if(ctx->ref_def_hashtable != NULL) {
         int i;
 
         for(i = 0; i < ctx->ref_def_hashtable_size; i++) {
             void* bucket = ctx->ref_def_hashtable[i];
             if(bucket == NULL)
                 continue;
             if(ctx->ref_defs <= (MD_REF_DEF*) bucket  &&  (MD_REF_DEF*) bucket < ctx->ref_defs + ctx->n_ref_defs)
                 continue;
             free(bucket);
         }
 
         free(ctx->ref_def_hashtable);
     }
 }
 
 static const MD_REF_DEF*
 md_lookup_ref_def(MD_CTX* ctx, const CHAR* label, SZ label_size)
 {
     unsigned hash;
     void* bucket;
 
     if(ctx->ref_def_hashtable_size == 0)
         return NULL;
 
     hash = md_link_label_hash(label, label_size);
     bucket = ctx->ref_def_hashtable[hash % ctx->ref_def_hashtable_size];
 
     if(bucket == NULL) {
         return NULL;
     } else if(ctx->ref_defs <= (MD_REF_DEF*) bucket  &&  (MD_REF_DEF*) bucket < ctx->ref_defs + ctx->n_ref_defs) {
         const MD_REF_DEF* def = (MD_REF_DEF*) bucket;
 
         if(md_link_label_cmp(def->label, def->label_size, label, label_size) == 0)
             return def;
         else
             return NULL;
     } else {
         MD_REF_DEF_LIST* list = (MD_REF_DEF_LIST*) bucket;
         MD_REF_DEF key_buf;
         const MD_REF_DEF* key = &key_buf;
         const MD_REF_DEF** ret;
 
         key_buf.label = (CHAR*) label;
         key_buf.label_size = label_size;
         key_buf.hash = md_link_label_hash(key_buf.label, key_buf.label_size);
 
         ret = (const MD_REF_DEF**) bsearch(&key, list->ref_defs,
                     list->n_ref_defs, sizeof(MD_REF_DEF*), md_ref_def_cmp);
         if(ret != NULL)
             return *ret;
         else
             return NULL;
     }
 }
 
 
 /***************************
  ***  Recognizing Links  ***
  ***************************/
 
 /* Note this code is partially shared between processing inlines and blocks
  * as reference definitions and links share some helper parser functions.
  */
 
 typedef struct MD_LINK_ATTR_tag MD_LINK_ATTR;
 struct MD_LINK_ATTR_tag {
     OFF dest_beg;
     OFF dest_end;
 
     CHAR* title;
     SZ title_size;
     int title_needs_free;
 };
 
 
 static int
 md_is_link_label(MD_CTX* ctx, const MD_LINE* lines, int n_lines, OFF beg,
                  OFF* p_end, int* p_beg_line_index, int* p_end_line_index,
                  OFF* p_contents_beg, OFF* p_contents_end)
 {
     OFF off = beg;
     OFF contents_beg = 0;
     OFF contents_end = 0;
     int line_index = 0;
     int len = 0;
 
     if(CH(off) != _T('['))
         return FALSE;
     off++;
 
     while(1) {
         OFF line_end = lines[line_index].end;
 
         while(off < line_end) {
             if(CH(off) == _T('\\')  &&  off+1 < ctx->size  &&  (ISPUNCT(off+1) || ISNEWLINE(off+1))) {
                 if(contents_end == 0) {
                     contents_beg = off;
                     *p_beg_line_index = line_index;
                 }
                 contents_end = off + 2;
                 off += 2;
             } else if(CH(off) == _T('[')) {
                 return FALSE;
             } else if(CH(off) == _T(']')) {
                 if(contents_beg < contents_end) {
                     /* Success. */
                     *p_contents_beg = contents_beg;
                     *p_contents_end = contents_end;
                     *p_end = off+1;
                     *p_end_line_index = line_index;
                     return TRUE;
                 } else {
                     /* Link label must have some non-whitespace contents. */
                     return FALSE;
                 }
             } else {
                 unsigned codepoint;
                 SZ char_size;
 
                 codepoint = md_decode_unicode(ctx->text, off, ctx->size, &char_size);
                 if(!ISUNICODEWHITESPACE_(codepoint)) {
                     if(contents_end == 0) {
                         contents_beg = off;
                         *p_beg_line_index = line_index;
                     }
                     contents_end = off + char_size;
                 }
 
                 off += char_size;
             }
 
             len++;
             if(len > 999)
                 return FALSE;
         }
 
         line_index++;
         len++;
         if(line_index < n_lines)
             off = lines[line_index].beg;
         else
             break;
     }
 
     return FALSE;
 }
 
 static int
 md_is_link_destination_A(MD_CTX* ctx, OFF beg, OFF max_end, OFF* p_end,
                          OFF* p_contents_beg, OFF* p_contents_end)
 {
     OFF off = beg;
 
     if(off >= max_end  ||  CH(off) != _T('<'))
         return FALSE;
     off++;
 
     while(off < max_end) {
         if(CH(off) == _T('\\')  &&  off+1 < max_end  &&  ISPUNCT(off+1)) {
             off += 2;
             continue;
         }
 
         if(ISNEWLINE(off)  ||  CH(off) == _T('<'))
             return FALSE;
 
         if(CH(off) == _T('>')) {
             /* Success. */
             *p_contents_beg = beg+1;
             *p_contents_end = off;
             *p_end = off+1;
             return TRUE;
         }
 
         off++;
     }
 
     return FALSE;
 }
 
 static int
 md_is_link_destination_B(MD_CTX* ctx, OFF beg, OFF max_end, OFF* p_end,
                          OFF* p_contents_beg, OFF* p_contents_end)
 {
     OFF off = beg;
     int parenthesis_level = 0;
 
     while(off < max_end) {
         if(CH(off) == _T('\\')  &&  off+1 < max_end  &&  ISPUNCT(off+1)) {
             off += 2;
             continue;
         }
 
         if(ISWHITESPACE(off) || ISCNTRL(off))
             break;
 
         /* Link destination may include balanced pairs of unescaped '(' ')'.
          * Note we limit the maximal nesting level by 32 to protect us from
          * https://github.com/jgm/cmark/issues/214 */
         if(CH(off) == _T('(')) {
             parenthesis_level++;
             if(parenthesis_level > 32)
                 return FALSE;
         } else if(CH(off) == _T(')')) {
             if(parenthesis_level == 0)
                 break;
             parenthesis_level--;
         }
 
         off++;
     }
 
     if(parenthesis_level != 0  ||  off == beg)
         return FALSE;
 
     /* Success. */
     *p_contents_beg = beg;
     *p_contents_end = off;
     *p_end = off;
     return TRUE;
 }
 
 static inline int
 md_is_link_destination(MD_CTX* ctx, OFF beg, OFF max_end, OFF* p_end,
                        OFF* p_contents_beg, OFF* p_contents_end)
 {
     if(CH(beg) == _T('<'))
         return md_is_link_destination_A(ctx, beg, max_end, p_end, p_contents_beg, p_contents_end);
     else
         return md_is_link_destination_B(ctx, beg, max_end, p_end, p_contents_beg, p_contents_end);
 }
 
 static int
 md_is_link_title(MD_CTX* ctx, const MD_LINE* lines, int n_lines, OFF beg,
                  OFF* p_end, int* p_beg_line_index, int* p_end_line_index,
                  OFF* p_contents_beg, OFF* p_contents_end)
 {
     OFF off = beg;
     CHAR closer_char;
     int line_index = 0;
 
     /* White space with up to one line break. */
     while(off < lines[line_index].end  &&  ISWHITESPACE(off))
         off++;
     if(off >= lines[line_index].end) {
         line_index++;
         if(line_index >= n_lines)
             return FALSE;
         off = lines[line_index].beg;
     }
     if(off == beg)
         return FALSE;
 
     *p_beg_line_index = line_index;
 
     /* First char determines how to detect end of it. */
     switch(CH(off)) {
         case _T('"'):   closer_char = _T('"'); break;
         case _T('\''):  closer_char = _T('\''); break;
         case _T('('):   closer_char = _T(')'); break;
         default:        return FALSE;
     }
     off++;
 
     *p_contents_beg = off;
 
     while(line_index < n_lines) {
         OFF line_end = lines[line_index].end;
 
         while(off < line_end) {
             if(CH(off) == _T('\\')  &&  off+1 < ctx->size  &&  (ISPUNCT(off+1) || ISNEWLINE(off+1))) {
                 off++;
             } else if(CH(off) == closer_char) {
                 /* Success. */
                 *p_contents_end = off;
                 *p_end = off+1;
                 *p_end_line_index = line_index;
                 return TRUE;
             } else if(closer_char == _T(')')  &&  CH(off) == _T('(')) {
                 /* ()-style title cannot contain (unescaped '(')) */
                 return FALSE;
             }
 
             off++;
         }
 
         line_index++;
     }
 
     return FALSE;
 }
 
 /* Returns 0 if it is not a reference definition.
  *
  * Returns N > 0 if it is a reference definition. N then corresponds to the
  * number of lines forming it). In this case the definition is stored for
  * resolving any links referring to it.
  *
  * Returns -1 in case of an error (out of memory).
  */
 static int
 md_is_link_reference_definition(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
 {
     OFF label_contents_beg;
     OFF label_contents_end;
     int label_contents_line_index = -1;
     int label_is_multiline = FALSE;
     OFF dest_contents_beg;
     OFF dest_contents_end;
     OFF title_contents_beg;
     OFF title_contents_end;
     int title_contents_line_index;
     int title_is_multiline = FALSE;
     OFF off;
     int line_index = 0;
     int tmp_line_index;
     MD_REF_DEF* def = NULL;
     int ret = 0;
 
     /* Link label. */
     if(!md_is_link_label(ctx, lines, n_lines, lines[0].beg,
                 &off, &label_contents_line_index, &line_index,
                 &label_contents_beg, &label_contents_end))
         return FALSE;
     label_is_multiline = (label_contents_line_index != line_index);
 
     /* Colon. */
     if(off >= lines[line_index].end  ||  CH(off) != _T(':'))
         return FALSE;
     off++;
 
     /* Optional white space with up to one line break. */
     while(off < lines[line_index].end  &&  ISWHITESPACE(off))
         off++;
     if(off >= lines[line_index].end) {
         line_index++;
         if(line_index >= n_lines)
             return FALSE;
         off = lines[line_index].beg;
     }
 
     /* Link destination. */
     if(!md_is_link_destination(ctx, off, lines[line_index].end,
                 &off, &dest_contents_beg, &dest_contents_end))
         return FALSE;
 
     /* (Optional) title. Note we interpret it as an title only if nothing
      * more follows on its last line. */
     if(md_is_link_title(ctx, lines + line_index, n_lines - line_index, off,
                 &off, &title_contents_line_index, &tmp_line_index,
                 &title_contents_beg, &title_contents_end)
         &&  off >= lines[line_index + tmp_line_index].end)
     {
         title_is_multiline = (tmp_line_index != title_contents_line_index);
         title_contents_line_index += line_index;
         line_index += tmp_line_index;
     } else {
         /* Not a title. */
         title_is_multiline = FALSE;
         title_contents_beg = off;
         title_contents_end = off;
         title_contents_line_index = 0;
     }
 
     /* Nothing more can follow on the last line. */
     if(off < lines[line_index].end)
         return FALSE;
 
     /* So, it _is_ a reference definition. Remember it. */
     if(ctx->n_ref_defs >= ctx->alloc_ref_defs) {
         MD_REF_DEF* new_defs;
 
         ctx->alloc_ref_defs = (ctx->alloc_ref_defs > 0
                 ? ctx->alloc_ref_defs + ctx->alloc_ref_defs / 2
                 : 16);
         new_defs = (MD_REF_DEF*) realloc(ctx->ref_defs, ctx->alloc_ref_defs * sizeof(MD_REF_DEF));
         if(new_defs == NULL) {
             MD_LOG("realloc() failed.");
             goto abort;
         }
 
         ctx->ref_defs = new_defs;
     }
     def = &ctx->ref_defs[ctx->n_ref_defs];
     memset(def, 0, sizeof(MD_REF_DEF));
 
     if(label_is_multiline) {
         MD_CHECK(md_merge_lines_alloc(ctx, label_contents_beg, label_contents_end,
                     lines + label_contents_line_index, n_lines - label_contents_line_index,
                     _T(' '), &def->label, &def->label_size));
         def->label_needs_free = TRUE;
     } else {
         def->label = (CHAR*) STR(label_contents_beg);
         def->label_size = label_contents_end - label_contents_beg;
     }
 
     if(title_is_multiline) {
         MD_CHECK(md_merge_lines_alloc(ctx, title_contents_beg, title_contents_end,
                     lines + title_contents_line_index, n_lines - title_contents_line_index,
                     _T('\n'), &def->title, &def->title_size));
         def->title_needs_free = TRUE;
     } else {
         def->title = (CHAR*) STR(title_contents_beg);
         def->title_size = title_contents_end - title_contents_beg;
     }
 
     def->dest_beg = dest_contents_beg;
     def->dest_end = dest_contents_end;
 
     /* Success. */
     ctx->n_ref_defs++;
     return line_index + 1;
 
 abort:
     /* Failure. */
     if(def != NULL  &&  def->label_needs_free)
         free(def->label);
     if(def != NULL  &&  def->title_needs_free)
         free(def->title);
     return ret;
 }
 
 static int
 md_is_link_reference(MD_CTX* ctx, const MD_LINE* lines, int n_lines,
                      OFF beg, OFF end, MD_LINK_ATTR* attr)
 {
     const MD_REF_DEF* def;
     const MD_LINE* beg_line;
     int is_multiline;
     CHAR* label;
     SZ label_size;
     int ret;
 
     MD_ASSERT(CH(beg) == _T('[') || CH(beg) == _T('!'));
     MD_ASSERT(CH(end-1) == _T(']'));
 
     beg += (CH(beg) == _T('!') ? 2 : 1);
     end--;
 
     /* Find lines corresponding to the beg and end positions. */
     beg_line = md_lookup_line(beg, lines, n_lines);
     is_multiline = (end > beg_line->end);
 
     if(is_multiline) {
         MD_CHECK(md_merge_lines_alloc(ctx, beg, end, beg_line,
                  (int)(n_lines - (beg_line - lines)), _T(' '), &label, &label_size));
     } else {
         label = (CHAR*) STR(beg);
         label_size = end - beg;
     }
 
     def = md_lookup_ref_def(ctx, label, label_size);
     if(def != NULL) {
         attr->dest_beg = def->dest_beg;
         attr->dest_end = def->dest_end;
         attr->title = def->title;
         attr->title_size = def->title_size;
         attr->title_needs_free = FALSE;
     }
 
     if(is_multiline)
         free(label);
 
     ret = (def != NULL);
 
 abort:
     return ret;
 }
 
 static int
 md_is_inline_link_spec(MD_CTX* ctx, const MD_LINE* lines, int n_lines,
                        OFF beg, OFF* p_end, MD_LINK_ATTR* attr)
 {
     int line_index = 0;
     int tmp_line_index;
     OFF title_contents_beg;
     OFF title_contents_end;
     int title_contents_line_index;
     int title_is_multiline;
     OFF off = beg;
     int ret = FALSE;
 
     while(off >= lines[line_index].end)
         line_index++;
 
     MD_ASSERT(CH(off) == _T('('));
     off++;
 
     /* Optional white space with up to one line break. */
     while(off < lines[line_index].end  &&  ISWHITESPACE(off))
         off++;
     if(off >= lines[line_index].end  &&  (off >= ctx->size  ||  ISNEWLINE(off))) {
         line_index++;
         if(line_index >= n_lines)
             return FALSE;
         off = lines[line_index].beg;
     }
 
     /* Link destination may be omitted, but only when not also having a title. */
     if(off < ctx->size  &&  CH(off) == _T(')')) {
         attr->dest_beg = off;
         attr->dest_end = off;
         attr->title = NULL;
         attr->title_size = 0;
         attr->title_needs_free = FALSE;
         off++;
         *p_end = off;
         return TRUE;
     }
 
     /* Link destination. */
     if(!md_is_link_destination(ctx, off, lines[line_index].end,
                         &off, &attr->dest_beg, &attr->dest_end))
         return FALSE;
 
     /* (Optional) title. */
     if(md_is_link_title(ctx, lines + line_index, n_lines - line_index, off,
                 &off, &title_contents_line_index, &tmp_line_index,
                 &title_contents_beg, &title_contents_end))
     {
         title_is_multiline = (tmp_line_index != title_contents_line_index);
         title_contents_line_index += line_index;
         line_index += tmp_line_index;
     } else {
         /* Not a title. */
         title_is_multiline = FALSE;
         title_contents_beg = off;
         title_contents_end = off;
         title_contents_line_index = 0;
     }
 
     /* Optional whitespace followed with final ')'. */
     while(off < lines[line_index].end  &&  ISWHITESPACE(off))
         off++;
     if (off >= lines[line_index].end  &&  (off >= ctx->size || ISNEWLINE(off))) {
         line_index++;
         if(line_index >= n_lines)
             return FALSE;
         off = lines[line_index].beg;
     }
     if(CH(off) != _T(')'))
         goto abort;
     off++;
 
     if(title_contents_beg >= title_contents_end) {
         attr->title = NULL;
         attr->title_size = 0;
         attr->title_needs_free = FALSE;
     } else if(!title_is_multiline) {
         attr->title = (CHAR*) STR(title_contents_beg);
         attr->title_size = title_contents_end - title_contents_beg;
         attr->title_needs_free = FALSE;
     } else {
         MD_CHECK(md_merge_lines_alloc(ctx, title_contents_beg, title_contents_end,
                     lines + title_contents_line_index, n_lines - title_contents_line_index,
                     _T('\n'), &attr->title, &attr->title_size));
         attr->title_needs_free = TRUE;
     }
 
     *p_end = off;
     ret = TRUE;
 
 abort:
     return ret;
 }
 
 static void
 md_free_ref_defs(MD_CTX* ctx)
 {
     int i;
 
     for(i = 0; i < ctx->n_ref_defs; i++) {
         MD_REF_DEF* def = &ctx->ref_defs[i];
 
         if(def->label_needs_free)
             free(def->label);
         if(def->title_needs_free)
             free(def->title);
     }
 
     free(ctx->ref_defs);
 }
 
 
 /******************************************
  ***  Processing Inlines (a.k.a Spans)  ***
  ******************************************/
 
 /* We process inlines in few phases:
  *
  * (1) We go through the block text and collect all significant characters
  *     which may start/end a span or some other significant position into
  *     ctx->marks[]. Core of this is what md_collect_marks() does.
  *
  *     We also do some very brief preliminary context-less analysis, whether
  *     it might be opener or closer (e.g. of an emphasis span).
  *
  *     This speeds the other steps as we do not need to re-iterate over all
  *     characters anymore.
  *
  * (2) We analyze each potential mark types, in order by their precedence.
  *
  *     In each md_analyze_XXX() function, we re-iterate list of the marks,
  *     skipping already resolved regions (in preceding precedences) and try to
  *     resolve them.
  *
  * (2.1) For trivial marks, which are single (e.g. HTML entity), we just mark
  *       them as resolved.
  *
  * (2.2) For range-type marks, we analyze whether the mark could be closer
  *       and, if yes, whether there is some preceding opener it could satisfy.
  *
  *       If not we check whether it could be really an opener and if yes, we
  *       remember it so subsequent closers may resolve it.
  *
  * (3) Finally, when all marks were analyzed, we render the block contents
  *     by calling MD_RENDERER::text() callback, interrupting by ::enter_span()
  *     or ::close_span() whenever we reach a resolved mark.
  */
 
 
 /* The mark structure.
  *
  * '\\': Maybe escape sequence.
  * '\0': NULL char.
  *  '*': Maybe (strong) emphasis start/end.
  *  '_': Maybe (strong) emphasis start/end.
  *  '~': Maybe strikethrough start/end (needs MD_FLAG_STRIKETHROUGH).
  *  '`': Maybe code span start/end.
  *  '&': Maybe start of entity.
  *  ';': Maybe end of entity.
  *  '<': Maybe start of raw HTML or autolink.
  *  '>': Maybe end of raw HTML or autolink.
  *  '[': Maybe start of link label or link text.
  *  '!': Equivalent of '[' for image.
  *  ']': Maybe end of link label or link text.
  *  '@': Maybe permissive e-mail auto-link (needs MD_FLAG_PERMISSIVEEMAILAUTOLINKS).
  *  ':': Maybe permissive URL auto-link (needs MD_FLAG_PERMISSIVEURLAUTOLINKS).
  *  '.': Maybe permissive WWW auto-link (needs MD_FLAG_PERMISSIVEWWWAUTOLINKS).
  *  'D': Dummy mark, it reserves a space for splitting a previous mark
  *       (e.g. emphasis) or to make more space for storing some special data
  *       related to the preceding mark (e.g. link).
  *
  * Note that not all instances of these chars in the text imply creation of the
  * structure. Only those which have (or may have, after we see more context)
  * the special meaning.
  *
  * (Keep this struct as small as possible to fit as much of them into CPU
  * cache line.)
  */
 struct MD_MARK_tag {
     OFF beg;
     OFF end;
 
     /* For unresolved openers, 'prev' and 'next' form the chain of open openers
      * of given type 'ch'.
      *
      * During resolving, we disconnect from the chain and point to the
      * corresponding counterpart so opener points to its closer and vice versa.
      */
     int prev;
     int next;
     CHAR ch;
     unsigned char flags;
 };
 
 /* Mark flags (these apply to ALL mark types). */
 #define MD_MARK_POTENTIAL_OPENER            0x01  /* Maybe opener. */
 #define MD_MARK_POTENTIAL_CLOSER            0x02  /* Maybe closer. */
 #define MD_MARK_OPENER                      0x04  /* Definitely opener. */
 #define MD_MARK_CLOSER                      0x08  /* Definitely closer. */
 #define MD_MARK_RESOLVED                    0x10  /* Resolved in any definite way. */
 
 /* Mark flags specific for various mark types (so they can share bits). */
 #define MD_MARK_EMPH_INTRAWORD              0x20  /* Helper for the "rule of 3". */
 #define MD_MARK_EMPH_MOD3_0                 0x40
 #define MD_MARK_EMPH_MOD3_1                 0x80
 #define MD_MARK_EMPH_MOD3_2                 (0x40 | 0x80)
 #define MD_MARK_EMPH_MOD3_MASK              (0x40 | 0x80)
 #define MD_MARK_AUTOLINK                    0x20  /* Distinguisher for '<', '>'. */
 #define MD_MARK_VALIDPERMISSIVEAUTOLINK     0x20  /* For permissive autolinks. */
 #define MD_MARK_HASNESTEDBRACKETS           0x20  /* For '[' to rule out invalid link labels early */
 
 static MD_MARKCHAIN*
 md_asterisk_chain(MD_CTX* ctx, unsigned flags)
 {
     switch(flags & (MD_MARK_EMPH_INTRAWORD | MD_MARK_EMPH_MOD3_MASK)) {
         case MD_MARK_EMPH_INTRAWORD | MD_MARK_EMPH_MOD3_0:  return &ASTERISK_OPENERS_intraword_mod3_0;
         case MD_MARK_EMPH_INTRAWORD | MD_MARK_EMPH_MOD3_1:  return &ASTERISK_OPENERS_intraword_mod3_1;
         case MD_MARK_EMPH_INTRAWORD | MD_MARK_EMPH_MOD3_2:  return &ASTERISK_OPENERS_intraword_mod3_2;
         case MD_MARK_EMPH_MOD3_0:                           return &ASTERISK_OPENERS_extraword_mod3_0;
         case MD_MARK_EMPH_MOD3_1:                           return &ASTERISK_OPENERS_extraword_mod3_1;
         case MD_MARK_EMPH_MOD3_2:                           return &ASTERISK_OPENERS_extraword_mod3_2;
         default:                                            MD_UNREACHABLE();
     }
     return NULL;
 }
 
 static MD_MARKCHAIN*
 md_mark_chain(MD_CTX* ctx, int mark_index)
 {
     MD_MARK* mark = &ctx->marks[mark_index];
 
     switch(mark->ch) {
         case _T('*'):   return md_asterisk_chain(ctx, mark->flags);
         case _T('_'):   return &UNDERSCORE_OPENERS;
         case _T('~'):   return (mark->end - mark->beg == 1) ? &TILDE_OPENERS_1 : &TILDE_OPENERS_2;
         /* case _T('!'):   MD_FALLTHROUGH(); */
         case _T('['):   return &BRACKET_OPENERS;
         case _T('|'):   return &TABLECELLBOUNDARIES;
         case _T('-'):   return &FAINT_OPENERS;
         case _T('%'):   return &INVERSE_OPENERS;
         case _T('!'):   return &CONCEAL_OPENERS;
         case _T('^'):   return &BLINK_OPENERS;
         default:        return NULL;
     }
 }
 
 static MD_MARK*
 md_push_mark(MD_CTX* ctx)
 {
     if(ctx->n_marks >= ctx->alloc_marks) {
         MD_MARK* new_marks;
 
         ctx->alloc_marks = (ctx->alloc_marks > 0
                 ? ctx->alloc_marks + ctx->alloc_marks / 2
                 : 64);
         new_marks = realloc(ctx->marks, ctx->alloc_marks * sizeof(MD_MARK));
         if(new_marks == NULL) {
             MD_LOG("realloc() failed.");
             return NULL;
         }
 
         ctx->marks = new_marks;
     }
 
     return &ctx->marks[ctx->n_marks++];
 }
 
 #define PUSH_MARK_()                                                    \
         do {                                                            \
             mark = md_push_mark(ctx);                                   \
             if(mark == NULL) {                                          \
                 ret = -1;                                               \
                 goto abort;                                             \
             }                                                           \
         } while(0)
 
 #define PUSH_MARK(ch_, beg_, end_, flags_)                              \
         do {                                                            \
             PUSH_MARK_();                                               \
             mark->beg = (beg_);                                         \
             mark->end = (end_);                                         \
             mark->prev = -1;                                            \
             mark->next = -1;                                            \
             mark->ch = (char)(ch_);                                     \
             mark->flags = (flags_);                                     \
         } while(0)
 
 
 static void
 md_mark_chain_append(MD_CTX* ctx, MD_MARKCHAIN* chain, int mark_index)
 {
     if(chain->tail >= 0)
         ctx->marks[chain->tail].next = mark_index;
     else
         chain->head = mark_index;
 
     ctx->marks[mark_index].prev = chain->tail;
     ctx->marks[mark_index].next = -1;
     chain->tail = mark_index;
 }
 
 /* Sometimes, we need to store a pointer into the mark. It is quite rare
  * so we do not bother to make MD_MARK use union, and it can only happen
  * for dummy marks. */
 static inline void
 md_mark_store_ptr(MD_CTX* ctx, int mark_index, void* ptr)
 {
     MD_MARK* mark = &ctx->marks[mark_index];
     MD_ASSERT(mark->ch == 'D');
 
     /* Check only members beg and end are misused for this. */
     MD_ASSERT(sizeof(void*) <= 2 * sizeof(OFF));
     memcpy(mark, &ptr, sizeof(void*));
 }
 
 static inline void*
 md_mark_get_ptr(MD_CTX* ctx, int mark_index)
 {
     void* ptr;
     MD_MARK* mark = &ctx->marks[mark_index];
     MD_ASSERT(mark->ch == 'D');
     memcpy(&ptr, mark, sizeof(void*));
     return ptr;
 }
 
 static void
 md_resolve_range(MD_CTX* ctx, MD_MARKCHAIN* chain, int opener_index, int closer_index)
 {
     MD_MARK* opener = &ctx->marks[opener_index];
     MD_MARK* closer = &ctx->marks[closer_index];
 
     /* Remove opener from the list of openers. */
     if(chain != NULL) {
         if(opener->prev >= 0)
             ctx->marks[opener->prev].next = opener->next;
         else
             chain->head = opener->next;
 
         if(opener->next >= 0)
             ctx->marks[opener->next].prev = opener->prev;
         else
             chain->tail = opener->prev;
     }
 
     /* Interconnect opener and closer and mark both as resolved. */
     opener->next = closer_index;
     opener->flags |= MD_MARK_OPENER | MD_MARK_RESOLVED;
     closer->prev = opener_index;
     closer->flags |= MD_MARK_CLOSER | MD_MARK_RESOLVED;
 }
 
 
 #define MD_ROLLBACK_ALL         0
 #define MD_ROLLBACK_CROSSING    1
 
 /* In the range ctx->marks[opener_index] ... [closer_index], undo some or all
  * resolvings accordingly to these rules:
  *
  * (1) All openers BEFORE the range corresponding to any closer inside the
  *     range are un-resolved and they are re-added to their respective chains
  *     of unresolved openers. This ensures we can reuse the opener for closers
  *     AFTER the range.
  *
  * (2) If 'how' is MD_ROLLBACK_ALL, then ALL resolved marks inside the range
  *     are discarded.
  *
  * (3) If 'how' is MD_ROLLBACK_CROSSING, only closers with openers handled
  *     in (1) are discarded. I.e. pairs of openers and closers which are both
  *     inside the range are retained as well as any unpaired marks.
  */
 static void
 md_rollback(MD_CTX* ctx, int opener_index, int closer_index, int how)
 {
     int i;
     int mark_index;
 
     /* Cut all unresolved openers at the mark index. */
     for(i = OPENERS_CHAIN_FIRST; i < OPENERS_CHAIN_LAST+1; i++) {
         MD_MARKCHAIN* chain = &ctx->mark_chains[i];
 
         while(chain->tail >= opener_index) {
             int same = chain->tail == opener_index;
             chain->tail = ctx->marks[chain->tail].prev;
             if (same) break;
         }
 
         if(chain->tail >= 0)
             ctx->marks[chain->tail].next = -1;
         else
             chain->head = -1;
     }
 
     /* Go backwards so that unresolved openers are re-added into their
      * respective chains, in the right order. */
     mark_index = closer_index - 1;
     while(mark_index > opener_index) {
         MD_MARK* mark = &ctx->marks[mark_index];
         int mark_flags = mark->flags;
         int discard_flag = (how == MD_ROLLBACK_ALL);
 
         if(mark->flags & MD_MARK_CLOSER) {
             int mark_opener_index = mark->prev;
 
             /* Undo opener BEFORE the range. */
             if(mark_opener_index < opener_index) {
                 MD_MARK* mark_opener = &ctx->marks[mark_opener_index];
                 MD_MARKCHAIN* chain;
 
                 mark_opener->flags &= ~(MD_MARK_OPENER | MD_MARK_CLOSER | MD_MARK_RESOLVED);
                 chain = md_mark_chain(ctx, opener_index);
                 if(chain != NULL) {
                     md_mark_chain_append(ctx, chain, mark_opener_index);
                     discard_flag = 1;
                 }
             }
         }
 
         /* And reset our flags. */
         if(discard_flag) {
             /* Make zero-length closer a dummy mark as that's how it was born */
             if((mark->flags & MD_MARK_CLOSER)  &&  mark->beg == mark->end)
                 mark->ch = 'D';
 
             mark->flags &= ~(MD_MARK_OPENER | MD_MARK_CLOSER | MD_MARK_RESOLVED);
         }
 
         /* Jump as far as we can over unresolved or non-interesting marks. */
         switch(how) {
             case MD_ROLLBACK_CROSSING:
                 if((mark_flags & MD_MARK_CLOSER)  &&  mark->prev > opener_index) {
                     /* If we are closer with opener INSIDE the range, there may
                      * not be any other crosser inside the subrange. */
                     mark_index = mark->prev;
                     break;
                 }
                 MD_FALLTHROUGH();
             default:
                 mark_index--;
                 break;
         }
     }
 }
 
 static void
 md_build_mark_char_map(MD_CTX* ctx)
 {
     memset(ctx->mark_char_map, 0, sizeof(ctx->mark_char_map));
 
     ctx->mark_char_map['\\'] = 1;
     ctx->mark_char_map['^'] = 1;
     ctx->mark_char_map['%'] = 1;
     ctx->mark_char_map['-'] = 1;
     ctx->mark_char_map['*'] = 1;
     ctx->mark_char_map['_'] = 1;
     ctx->mark_char_map['`'] = 1;
     ctx->mark_char_map['&'] = 1;
     ctx->mark_char_map[';'] = 1;
     ctx->mark_char_map['<'] = 1;
     ctx->mark_char_map['>'] = 1;
     ctx->mark_char_map['['] = 1;
     ctx->mark_char_map['!'] = 1;
     ctx->mark_char_map[']'] = 1;
     ctx->mark_char_map['\0'] = 1;
 
     if(ctx->parser.flags & MD_FLAG_STRIKETHROUGH)
         ctx->mark_char_map['~'] = 1;
 
     if(ctx->parser.flags & MD_FLAG_LATEXMATHSPANS)
         ctx->mark_char_map['$'] = 1;
 
     if(ctx->parser.flags & MD_FLAG_PERMISSIVEEMAILAUTOLINKS)
         ctx->mark_char_map['@'] = 1;
 
     if(ctx->parser.flags & MD_FLAG_PERMISSIVEURLAUTOLINKS)
         ctx->mark_char_map[':'] = 1;
 
     if(ctx->parser.flags & MD_FLAG_PERMISSIVEWWWAUTOLINKS)
         ctx->mark_char_map['.'] = 1;
 
     if((ctx->parser.flags & MD_FLAG_TABLES) || (ctx->parser.flags & MD_FLAG_WIKILINKS))
         ctx->mark_char_map['|'] = 1;
 
     if(ctx->parser.flags & MD_FLAG_COLLAPSEWHITESPACE) {
         int i;
 
         for(i = 0; i < (int) sizeof(ctx->mark_char_map); i++) {
             if(ISWHITESPACE_(i))
                 ctx->mark_char_map[i] = 1;
         }
     }
 }
 
 /* We limit code span marks to lower than 32 backticks. This solves the
  * pathologic case of too many openers, each of different length: Their
  * resolving would be then O(n^2). */
 #define CODESPAN_MARK_MAXLEN    32
 
 static int
 md_is_code_span(MD_CTX* ctx, const MD_LINE* lines, int n_lines, OFF beg,
                 OFF* p_opener_beg, OFF* p_opener_end,
                 OFF* p_closer_beg, OFF* p_closer_end,
                 OFF last_potential_closers[CODESPAN_MARK_MAXLEN],
                 int* p_reached_paragraph_end)
 {
     OFF opener_beg = beg;
     OFF opener_end;
     OFF closer_beg;
     OFF closer_end;
     SZ mark_len;
     OFF line_end;
     int has_space_after_opener = FALSE;
     int has_eol_after_opener = FALSE;
     int has_space_before_closer = FALSE;
     int has_eol_before_closer = FALSE;
     int has_only_space = TRUE;
     int line_index = 0;
 
     line_end = lines[0].end;
     opener_end = opener_beg;
     while(opener_end < line_end  &&  CH(opener_end) == _T('`'))
         opener_end++;
     has_space_after_opener = (opener_end < line_end && CH(opener_end) == _T(' '));
     has_eol_after_opener = (opener_end == line_end);
 
     /* The caller needs to know end of the opening mark even if we fail. */
     *p_opener_end = opener_end;
 
     mark_len = opener_end - opener_beg;
     if(mark_len > CODESPAN_MARK_MAXLEN)
         return FALSE;
 
     /* Check whether we already know there is no closer of this length.
      * If so, re-scan does no sense. This fixes issue #59. */
     if(last_potential_closers[mark_len-1] >= lines[n_lines-1].end  ||
        (*p_reached_paragraph_end  &&  last_potential_closers[mark_len-1] < opener_end))
         return FALSE;
 
     closer_beg = opener_end;
     closer_end = opener_end;
 
     /* Find closer mark. */
     while(TRUE) {
         while(closer_beg < line_end  &&  CH(closer_beg) != _T('`')) {
             if(CH(closer_beg) != _T(' '))
                 has_only_space = FALSE;
             closer_beg++;
         }
         closer_end = closer_beg;
         while(closer_end < line_end  &&  CH(closer_end) == _T('`'))
             closer_end++;
 
         if(closer_end - closer_beg == mark_len) {
             /* Success. */
             has_space_before_closer = (closer_beg > lines[line_index].beg && CH(closer_beg-1) == _T(' '));
             has_eol_before_closer = (closer_beg == lines[line_index].beg);
             break;
         }
 
         if(closer_end - closer_beg > 0) {
             /* We have found a back-tick which is not part of the closer. */
             has_only_space = FALSE;
 
             /* But if we eventually fail, remember it as a potential closer
              * of its own length for future attempts. This mitigates needs for
              * rescans. */
             if(closer_end - closer_beg < CODESPAN_MARK_MAXLEN) {
                 if(closer_beg > last_potential_closers[closer_end - closer_beg - 1])
                     last_potential_closers[closer_end - closer_beg - 1] = closer_beg;
             }
         }
 
         if(closer_end >= line_end) {
             line_index++;
             if(line_index >= n_lines) {
                 /* Reached end of the paragraph and still nothing. */
                 *p_reached_paragraph_end = TRUE;
                 return FALSE;
             }
             /* Try on the next line. */
             line_end = lines[line_index].end;
             closer_beg = lines[line_index].beg;
         } else {
             closer_beg = closer_end;
         }
     }
 
     /* If there is a space or a new line both after and before the opener
      * (and if the code span is not made of spaces only), consume one initial
      * and one trailing space as part of the marks. */
     if(!has_only_space  &&
        (has_space_after_opener || has_eol_after_opener)  &&
        (has_space_before_closer || has_eol_before_closer))
     {
         if(has_space_after_opener)
             opener_end++;
         else
             opener_end = lines[1].beg;
 
         if(has_space_before_closer)
             closer_beg--;
         else {
             closer_beg = lines[line_index-1].end;
             /* We need to eat the preceding "\r\n" but not any line trailing
              * spaces. */
             while(closer_beg < ctx->size  &&  ISBLANK(closer_beg))
                 closer_beg++;
         }
     }
 
     *p_opener_beg = opener_beg;
     *p_opener_end = opener_end;
     *p_closer_beg = closer_beg;
     *p_closer_end = closer_end;
     return TRUE;
 }
 
 /* detect anchors with syntax: [|anchorId] */
 static int
 md_is_anchor_span(MD_CTX* ctx, const MD_LINE* lines, OFF off, OFF* p_closer_beg)
 {
     OFF line_end = lines[0].end;
     // Smallest anchor is [|x]
     // An anchor must be on a single line
     if (off+4 >= line_end)
         return FALSE;
     off += 2;
 
     // Find closer mark
     int opener_end = off;
     while (off < line_end) {
         if (CH(off) == _T(']')) {
             // Check if there an id for the anchor
             if (off == opener_end)
                 return FALSE;
             *p_closer_beg = off;
             return TRUE;
         }
         off++;
     }
     return FALSE;
 }
 
 #ifdef MD4C_USE_UTF16
     /* For UTF-16, mark_char_map[] covers only ASCII. */
     #define IS_MARK_CHAR(off)   ((CH(off) < SIZEOF_ARRAY(ctx->mark_char_map))  &&  \
                                 (ctx->mark_char_map[(unsigned char) CH(off)]))
 #else
     /* For 8-bit encodings, mark_char_map[] covers all 256 elements. */
     #define IS_MARK_CHAR(off)   (ctx->mark_char_map[(unsigned char) CH(off)])
 #endif
 
 /* detect faint effect: -text text- */
 static int
 md_is_faint_span(MD_CTX* ctx, const MD_LINE* lines, OFF beg, OFF* p_closer_beg)
 {
     OFF tmp;
     OFF line_end;
 
     line_end = lines[0].end;
     if (beg+2 >= line_end)
         return FALSE;
     if (ISUNICODEWHITESPACE(beg+1))
         return FALSE;
     tmp = beg+2;
     while (tmp < line_end) {
         if (CH(tmp) == _T('-') && (tmp+1 == line_end || ISUNICODEWHITESPACE(tmp+1) || IS_MARK_CHAR(tmp+1))
             && (!ISUNICODEWHITESPACE(tmp-1))) {
             *p_closer_beg = tmp;
             return TRUE;
         }
         tmp++;
     }
 
     return FALSE;
 }
 
 /* detect inverse effect: %text text% */
 static int
 md_is_inverse_span(MD_CTX* ctx, const MD_LINE* lines, OFF beg, OFF* p_closer_beg)
 {
     OFF tmp;
     OFF line_end;
 
     line_end = lines[0].end;
     if (beg+2 >= line_end)
         return FALSE;
     if (ISUNICODEWHITESPACE(beg+1))
         return FALSE;
     tmp = beg+2;
     while (tmp < line_end) {
         if (CH(tmp) == _T('%') && (tmp+1 == line_end || ISUNICODEWHITESPACE(tmp+1) || IS_MARK_CHAR(tmp+1))
             && (!ISUNICODEWHITESPACE(tmp-1))) {
             *p_closer_beg = tmp;
             return TRUE;
         }
         tmp++;
     }
 
     return FALSE;
 }
 
 /* detect conceal effect: !text text! */
 static int
 md_is_conceal_span(MD_CTX* ctx, const MD_LINE* lines, OFF beg, OFF* p_closer_beg)
 {
     OFF tmp;
     OFF line_end;
 
     line_end = lines[0].end;
     if (beg+2 >= line_end)
         return FALSE;
     if (ISUNICODEWHITESPACE(beg+1))
         return FALSE;
     tmp = beg+2;
     while (tmp < line_end) {
         if (CH(tmp) == _T('!') && (tmp+1 == line_end || ISUNICODEWHITESPACE(tmp+1) || IS_MARK_CHAR(tmp+1))
             && (!ISUNICODEWHITESPACE(tmp-1))) {
             *p_closer_beg = tmp;
             return TRUE;
         }
         tmp++;
     }
 
     return FALSE;
 }
 
 /* detect blink effect: ^text text^ */
 static int
 md_is_blink_span(MD_CTX* ctx, const MD_LINE* lines, OFF beg, OFF* p_closer_beg)
 {
     OFF tmp;
     OFF line_end;
 
     line_end = lines[0].end;
     if (beg+2 >= line_end)
         return FALSE;
     if (ISUNICODEWHITESPACE(beg+1))
         return FALSE;
     tmp = beg+2;
     while (tmp < line_end) {
         if (CH(tmp) == _T('^') && (tmp+1 == line_end || ISUNICODEWHITESPACE(tmp+1) || IS_MARK_CHAR(tmp+1))
             && (!ISUNICODEWHITESPACE(tmp-1))) {
             *p_closer_beg = tmp;
             return TRUE;
         }
         tmp++;
     }
 
     return FALSE;
 }
 
 static int
 md_is_autolink_uri(MD_CTX* ctx, OFF beg, OFF max_end, OFF* p_end)
 {
     OFF off = beg+1;
 
     MD_ASSERT(CH(beg) == _T('<'));
 
     /* Check for scheme. */
     if(off >= max_end  ||  !ISASCII(off))
         return FALSE;
     off++;
     while(1) {
         if(off >= max_end)
             return FALSE;
         if(off - beg > 32)
             return FALSE;
         if(CH(off) == _T(':')  &&  off - beg >= 3)
             break;
         if(!ISALNUM(off) && CH(off) != _T('+') && CH(off) != _T('-') && CH(off) != _T('.'))
             return FALSE;
         off++;
     }
 
     /* Check the path after the scheme. */
     while(off < max_end  &&  CH(off) != _T('>')) {
         if(ISWHITESPACE(off) || ISCNTRL(off) || CH(off) == _T('<'))
             return FALSE;
         off++;
     }
 
     if(off >= max_end)
         return FALSE;
 
     MD_ASSERT(CH(off) == _T('>'));
     *p_end = off+1;
     return TRUE;
 }
 
 static int
 md_is_autolink_email(MD_CTX* ctx, OFF beg, OFF max_end, OFF* p_end)
 {
     OFF off = beg + 1;
     int label_len;
 
     MD_ASSERT(CH(beg) == _T('<'));
 
     /* The code should correspond to this regexp:
             /^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+
             @[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?
             (?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/
      */
 
     /* Username (before '@'). */
     while(off < max_end  &&  (ISALNUM(off) || ISANYOF(off, _T(".!#$%&'*+/=?^_`{|}~-"))))
         off++;
     if(off <= beg+1)
         return FALSE;
 
     /* '@' */
     if(off >= max_end  ||  CH(off) != _T('@'))
         return FALSE;
     off++;
 
     /* Labels delimited with '.'; each label is sequence of 1 - 63 alnum
      * characters or '-', but '-' is not allowed as first or last char. */
     label_len = 0;
     while(off < max_end) {
         if(ISALNUM(off))
             label_len++;
         else if(CH(off) == _T('-')  &&  label_len > 0)
             label_len++;
         else if(CH(off) == _T('.')  &&  label_len > 0  &&  CH(off-1) != _T('-'))
             label_len = 0;
         else
             break;
 
         if(label_len > 63)
             return FALSE;
 
         off++;
     }
 
     if(label_len <= 0  || off >= max_end  ||  CH(off) != _T('>') ||  CH(off-1) == _T('-'))
         return FALSE;
 
     *p_end = off+1;
     return TRUE;
 }
 
 static int
 md_is_autolink(MD_CTX* ctx, OFF beg, OFF max_end, OFF* p_end, int* p_missing_mailto)
 {
     if(md_is_autolink_uri(ctx, beg, max_end, p_end)) {
         *p_missing_mailto = FALSE;
         return TRUE;
     }
 
     if(md_is_autolink_email(ctx, beg, max_end, p_end)) {
         *p_missing_mailto = TRUE;
         return TRUE;
     }
 
     return FALSE;
 }
 
 static int
 md_collect_marks(MD_CTX* ctx, const MD_LINE* lines, int n_lines, int table_mode)
 {
     const MD_LINE* line_term = lines + n_lines;
     const MD_LINE* line;
     int ret = 0;
     MD_MARK* mark;
     OFF codespan_last_potential_closers[CODESPAN_MARK_MAXLEN] = { 0 };
     int codespan_scanned_till_paragraph_end = FALSE;
 
     for(line = lines; line < line_term; line++) {
         OFF off = line->beg;
         OFF line_end = line->end;
 
         while(TRUE) {
             CHAR ch;
 
             /* Optimization: Use some loop unrolling. */
             while(off + 3 < line_end  &&  !IS_MARK_CHAR(off+0)  &&  !IS_MARK_CHAR(off+1)
                                       &&  !IS_MARK_CHAR(off+2)  &&  !IS_MARK_CHAR(off+3))
                 off += 4;
             while(off < line_end  &&  !IS_MARK_CHAR(off+0))
                 off++;
 
             if(off >= line_end)
                 break;
 
             ch = CH(off);
 
             /* A backslash escape.
              * It can go beyond line->end as it may involve escaped new
              * line to form a hard break. */
             if(ch == _T('\\')  &&  off+1 < ctx->size  &&  (ISPUNCT(off+1) || ISNEWLINE(off+1))) {
                 /* Hard-break cannot be on the last line of the block. */
                 if(!ISNEWLINE(off+1)  ||  line+1 < line_term)
                     PUSH_MARK(ch, off, off+2, MD_MARK_RESOLVED);
                 off += 2;
                 continue;
             }
 
             /* A potential (string) emphasis start/end. */
             if(ch == _T('*')  ||  ch == _T('_')) {
                 OFF tmp = off+1;
                 int left_level;     /* What precedes: 0 = whitespace; 1 = punctuation; 2 = other char. */
                 int right_level;    /* What follows: 0 = whitespace; 1 = punctuation; 2 = other char. */
 
                 while(tmp < line_end  &&  CH(tmp) == ch)
                     tmp++;
 
                 if(off == line->beg  ||  ISUNICODEWHITESPACEBEFORE(off))
                     left_level = 0;
                 else if(ISUNICODEPUNCTBEFORE(off))
                     left_level = 1;
                 else
                     left_level = 2;
 
                 if(tmp == line_end  ||  ISUNICODEWHITESPACE(tmp))
                     right_level = 0;
                 else if(ISUNICODEPUNCT(tmp))
                     right_level = 1;
                 else
                     right_level = 2;
 
                 /* Intra-word underscore doesn't have special meaning. */
                 if(ch == _T('_')  &&  left_level == 2  &&  right_level == 2) {
                     left_level = 0;
                     right_level = 0;
                 }
 
                 if(left_level != 0  ||  right_level != 0) {
                     unsigned flags = 0;
 
                     if(left_level > 0  &&  left_level >= right_level)
                         flags |= MD_MARK_POTENTIAL_CLOSER;
                     if(right_level > 0  &&  right_level >= left_level)
                         flags |= MD_MARK_POTENTIAL_OPENER;
                     if(left_level == 2  &&  right_level == 2)
                         flags |= MD_MARK_EMPH_INTRAWORD;
 
                     /* For "the rule of three" we need to remember the original
                      * size of the mark (modulo three), before we potentially
                      * split the mark when being later resolved partially by some
                      * shorter closer. */
                     switch((tmp - off) % 3) {
                         case 0: flags |= MD_MARK_EMPH_MOD3_0; break;
                         case 1: flags |= MD_MARK_EMPH_MOD3_1; break;
                         case 2: flags |= MD_MARK_EMPH_MOD3_2; break;
                     }
 
                     PUSH_MARK(ch, off, tmp, flags);
 
                     /* During resolving, multiple asterisks may have to be
                      * split into independent span start/ends. Consider e.g.
                      * "**foo* bar*". Therefore we push also some empty dummy
                      * marks to have enough space for that. */
                     off++;
                     while(off < tmp) {
                         PUSH_MARK('D', off, off, 0);
                         off++;
                     }
                     continue;
                 }
 
                 off = tmp;
                 continue;
             }
 
             /* A potential code span start/end. */
             if(ch == _T('`')) {
                 OFF opener_beg, opener_end;
                 OFF closer_beg, closer_end;
                 int is_code_span;
 
                 is_code_span = md_is_code_span(ctx, line, line_term - line, off,
                                     &opener_beg, &opener_end, &closer_beg, &closer_end,
                                     codespan_last_potential_closers,
                                     &codespan_scanned_till_paragraph_end);
                 if(is_code_span) {
                     PUSH_MARK(_T('`'), opener_beg, opener_end, MD_MARK_OPENER | MD_MARK_RESOLVED);
                     PUSH_MARK(_T('`'), closer_beg, closer_end, MD_MARK_CLOSER | MD_MARK_RESOLVED);
                     ctx->marks[ctx->n_marks-2].next = ctx->n_marks-1;
                     ctx->marks[ctx->n_marks-1].prev = ctx->n_marks-2;
 
                     off = closer_end;
 
                     /* Advance the current line accordingly. */
                     if(off > line_end) {
                         line = md_lookup_line(off, line, line_term - line);
                         line_end = line->end;
                     }
                     continue;
                 }
 
                 off = opener_end;
                 continue;
             }
 
             /* A potential faint span start/end. */
             if(ch == _T('-')) {
                 OFF closer_beg;
                 int is_faint_span;
 
                 if (off == line->beg  ||  ISUNICODEWHITESPACEBEFORE(off) || ISUNICODEPUNCTBEFORE(off)
                     || IS_MARK_CHAR(off-1)) {
 
                     is_faint_span = md_is_faint_span(ctx, line, off, &closer_beg);
                     if(is_faint_span) {
                         PUSH_MARK(_T('-'), off, off+1, MD_MARK_OPENER | MD_MARK_RESOLVED);
                         PUSH_MARK(_T('-'), closer_beg, closer_beg+1, MD_MARK_CLOSER | MD_MARK_RESOLVED);
                         ctx->marks[ctx->n_marks-2].next = ctx->n_marks-1;
                         ctx->marks[ctx->n_marks-1].prev = ctx->n_marks-2;
                     }
                 }
                 off++;
                 continue;
             }
 
             /* A potential inverse span start/end. */
             if(ch == _T('%')) {
                 OFF closer_beg;
                 int is_inverse_span;
 
                 if (off == line->beg  ||  ISUNICODEWHITESPACEBEFORE(off) || ISUNICODEPUNCTBEFORE(off)
                     || IS_MARK_CHAR(off-1)) {
 
                     is_inverse_span = md_is_inverse_span(ctx, line, off, &closer_beg);
                     if(is_inverse_span) {
                         PUSH_MARK(_T('%'), off, off+1, MD_MARK_OPENER | MD_MARK_RESOLVED);
                         PUSH_MARK(_T('%'), closer_beg, closer_beg+1, MD_MARK_CLOSER | MD_MARK_RESOLVED);
                         ctx->marks[ctx->n_marks-2].next = ctx->n_marks-1;
                         ctx->marks[ctx->n_marks-1].prev = ctx->n_marks-2;
 
                     }
                 }
                 off++;
                 continue;
             }
 
             /* A potential conceal span start/end. */
             if(ch == _T('!')) {
                 OFF closer_beg;
                 int is_conceal_span;
 
                 if (off == line->beg  ||  ISUNICODEWHITESPACEBEFORE(off) || ISUNICODEPUNCTBEFORE(off)
                     || IS_MARK_CHAR(off-1)) {
 
                     is_conceal_span = md_is_conceal_span(ctx, line, off, &closer_beg);
                     if(is_conceal_span) {
                         PUSH_MARK(_T('!'), off, off+1, MD_MARK_OPENER | MD_MARK_RESOLVED);
                         PUSH_MARK(_T('!'), closer_beg, closer_beg+1, MD_MARK_CLOSER | MD_MARK_RESOLVED);
                         ctx->marks[ctx->n_marks-2].next = ctx->n_marks-1;
                         ctx->marks[ctx->n_marks-1].prev = ctx->n_marks-2;
 
                     }
                 }
                 off++;
                 continue;
             }
 
             /* A potential blink span start/end. */
             if(ch == _T('^')) {
                 OFF closer_beg;
                 int is_blink_span;
 
                 if (off == line->beg  ||  ISUNICODEWHITESPACEBEFORE(off) || ISUNICODEPUNCTBEFORE(off)
                     || IS_MARK_CHAR(off-1)) {
 
                     is_blink_span = md_is_blink_span(ctx, line, off, &closer_beg);
                     if(is_blink_span) {
                         PUSH_MARK(_T('^'), off, off+1, MD_MARK_OPENER | MD_MARK_RESOLVED);
                         PUSH_MARK(_T('^'), closer_beg, closer_beg+1, MD_MARK_CLOSER | MD_MARK_RESOLVED);
                         ctx->marks[ctx->n_marks-2].next = ctx->n_marks-1;
                         ctx->marks[ctx->n_marks-1].prev = ctx->n_marks-2;
 
                     }
                 }
                 off++;
                 continue;
             }
 
             /* A potential entity start. */
             if(ch == _T('&')) {
                 PUSH_MARK(ch, off, off+1, MD_MARK_POTENTIAL_OPENER);
                 off++;
                 continue;
             }
 
             /* A potential entity end. */
             if(ch == _T(';')) {
                 /* We surely cannot be entity unless the previous mark is '&'. */
                 if(ctx->n_marks > 0  &&  ctx->marks[ctx->n_marks-1].ch == _T('&'))
                     PUSH_MARK(ch, off, off+1, MD_MARK_POTENTIAL_CLOSER);
 
                 off++;
                 continue;
             }
 
             /* A potential autolink or raw HTML start/end. */
             if(ch == _T('<')) {
                 int is_autolink;
                 OFF autolink_end;
                 int missing_mailto;
 
                 if(!(ctx->parser.flags & MD_FLAG_NOHTMLSPANS)) {
                     int is_html;
                     OFF html_end;
 
                     /* Given the nature of the raw HTML, we have to recognize
                      * it here. Doing so later in md_analyze_lt_gt() could
                      * open can of worms of quadratic complexity. */
                     is_html = md_is_html_any(ctx, line, line_term - line, off,
                                     lines[n_lines-1].end, &html_end);
                     if(is_html) {
                         PUSH_MARK(_T('<'), off, off, MD_MARK_OPENER | MD_MARK_RESOLVED);
                         PUSH_MARK(_T('>'), html_end, html_end, MD_MARK_CLOSER | MD_MARK_RESOLVED);
                         ctx->marks[ctx->n_marks-2].next = ctx->n_marks-1;
                         ctx->marks[ctx->n_marks-1].prev = ctx->n_marks-2;
                         off = html_end;
 
                         /* Advance the current line accordingly. */
                         if(off > line_end) {
                             line = md_lookup_line(off, line, line_term - line);
                             line_end = line->end;
                         }
                         continue;
                     }
                 }
 
                 is_autolink = md_is_autolink(ctx, off, lines[n_lines-1].end,
                                     &autolink_end, &missing_mailto);
                 if(is_autolink) {
                     PUSH_MARK((missing_mailto ? _T('@') : _T('<')), off, off+1,
                                 MD_MARK_OPENER | MD_MARK_RESOLVED | MD_MARK_AUTOLINK);
                     PUSH_MARK(_T('>'), autolink_end-1, autolink_end,
                                 MD_MARK_CLOSER | MD_MARK_RESOLVED | MD_MARK_AUTOLINK);
                     ctx->marks[ctx->n_marks-2].next = ctx->n_marks-1;
                     ctx->marks[ctx->n_marks-1].prev = ctx->n_marks-2;
                     off = autolink_end;
                     continue;
                 }
 
                 off++;
                 continue;
             }
 
             /* A potential anchor */
             if(ch == _T('[') && off+1 < line_end && CH(off+1) == _T('|')) {
                 OFF closer_beg;
                 int is_anchor_span = md_is_anchor_span(ctx, line, off, &closer_beg);
                 if (is_anchor_span) {
                     PUSH_MARK(_T('['), off, off+2, MD_MARK_OPENER | MD_MARK_RESOLVED);
                     PUSH_MARK(_T(']'), closer_beg, closer_beg+1, MD_MARK_CLOSER | MD_MARK_RESOLVED);
                     ctx->marks[ctx->n_marks-2].next = ctx->n_marks-1;
                     ctx->marks[ctx->n_marks-1].prev = ctx->n_marks-2;
                     off = closer_beg+1;
                     continue;
                 }
                 // continue analyzing [ mark
             }
 
             /* A potential link or its part. */
             if(ch == _T('[')  ||  (ch == _T('!') && off+1 < line_end && CH(off+1) == _T('['))) {
                 OFF tmp = (ch == _T('[') ? off+1 : off+2);
                 PUSH_MARK(ch, off, tmp, MD_MARK_POTENTIAL_OPENER);
                 off = tmp;
                 /* Two dummies to make enough place for data we need if it is
                  * a link. */
                 PUSH_MARK('D', off, off, 0);
                 PUSH_MARK('D', off, off, 0);
                 continue;
             }
             if(ch == _T(']')) {
                 PUSH_MARK(ch, off, off+1, MD_MARK_POTENTIAL_CLOSER);
                 off++;
                 continue;
             }
 
             /* A potential permissive e-mail autolink. */
             if(ch == _T('@')) {
                 if(line->beg + 1 <= off  &&  ISALNUM(off-1)  &&
                     off + 3 < line->end  &&  ISALNUM(off+1))
                 {
                     PUSH_MARK(ch, off, off+1, MD_MARK_POTENTIAL_OPENER);
                     /* Push a dummy as a reserve for a closer. */
                     PUSH_MARK('D', off, off, 0);
                 }
 
                 off++;
                 continue;
             }
 
             /* A potential permissive URL autolink. */
             if(ch == _T(':')) {
                 static struct {
                     const CHAR* scheme;
                     SZ scheme_size;
                     const CHAR* suffix;
                     SZ suffix_size;
                 } scheme_map[] = {
                     /* In the order from the most frequently used, arguably. */
                     { _T("https"), 5,   _T("//"), 2 },
                     { _T("gemini"), 6,   _T("//"), 2 },
                     { _T("http"), 4,    _T("//"), 2 },
                     { _T("gopher"), 6,   _T("//"), 2 },
                     { _T("spartan"), 7,    _T("//"), 2 },
                     { _T("ftp"), 3,     _T("//"), 2 }
                 };
                 int scheme_index;
 
                 for(scheme_index = 0; scheme_index < (int) SIZEOF_ARRAY(scheme_map); scheme_index++) {
                     const CHAR* scheme = scheme_map[scheme_index].scheme;
                     const SZ scheme_size = scheme_map[scheme_index].scheme_size;
                     const CHAR* suffix = scheme_map[scheme_index].suffix;
                     const SZ suffix_size = scheme_map[scheme_index].suffix_size;
 
                     if(line->beg + scheme_size <= off  &&  md_ascii_eq(STR(off-scheme_size), scheme, scheme_size)  &&
                         (line->beg + scheme_size == off || ISWHITESPACE(off-scheme_size-1) || ISANYOF(off-scheme_size-1, _T("*_~([")))  &&
                         off + 1 + suffix_size < line->end  &&  md_ascii_eq(STR(off+1), suffix, suffix_size))
                     {
                         PUSH_MARK(ch, off-scheme_size, off+1+suffix_size, MD_MARK_POTENTIAL_OPENER);
                         /* Push a dummy as a reserve for a closer. */
                         PUSH_MARK('D', off, off, 0);
                         off += 1 + suffix_size;
                         break;
                     }
                 }
 
                 off++;
                 continue;
             }
 
             /* A potential permissive WWW autolink. */
             if(ch == _T('.')) {
                 if(line->beg + 3 <= off  &&  md_ascii_eq(STR(off-3), _T("www"), 3)  &&
                     (line->beg + 3 == off || ISWHITESPACE(off-4) || ISANYOF(off-4, _T("*_~([")))  &&
                     off + 1 < line_end)
                 {
                     PUSH_MARK(ch, off-3, off+1, MD_MARK_POTENTIAL_OPENER);
                     /* Push a dummy as a reserve for a closer. */
                     PUSH_MARK('D', off, off, 0);
                     off++;
                     continue;
                 }
 
                 off++;
                 continue;
             }
 
             /* A potential table cell boundary or wiki link label delimiter. */
             if((table_mode || ctx->parser.flags & MD_FLAG_WIKILINKS) && ch == _T('|')) {
                 PUSH_MARK(ch, off, off+1, 0);
                 off++;
                 continue;
             }
 
             /* A potential strikethrough start/end. */
             if(ch == _T('~')) {
                 OFF tmp = off+1;
 
                 while(tmp < line_end  &&  CH(tmp) == _T('~'))
                     tmp++;
 
                 if(tmp - off < 3) {
                     unsigned flags = 0;
 
                     if(tmp < line_end  &&  !ISUNICODEWHITESPACE(tmp))
                         flags |= MD_MARK_POTENTIAL_OPENER;
                     if(off > line->beg  &&  !ISUNICODEWHITESPACEBEFORE(off))
                         flags |= MD_MARK_POTENTIAL_CLOSER;
                     if(flags != 0)
                         PUSH_MARK(ch, off, tmp, flags);
                 }
 
                 off = tmp;
                 continue;
             }
 
             /* A potential equation start/end */
             if(ch == _T('$')) {
                 /* We can have at most two consecutive $ signs,
                  * where two dollar signs signify a display equation. */
                 OFF tmp = off+1;
 
                 while(tmp < line_end && CH(tmp) == _T('$'))
                     tmp++;
 
                 if (tmp - off <= 2)
                     PUSH_MARK(ch, off, tmp, MD_MARK_POTENTIAL_OPENER | MD_MARK_POTENTIAL_CLOSER);
                 off = tmp;
                 continue;
             }
 
             /* Turn non-trivial whitespace into single space. */
             if(ISWHITESPACE_(ch)) {
                 OFF tmp = off+1;
 
                 while(tmp < line_end  &&  ISWHITESPACE(tmp))
                     tmp++;
 
                 if(tmp - off > 1  ||  ch != _T(' '))
                     PUSH_MARK(ch, off, tmp, MD_MARK_RESOLVED);
 
                 off = tmp;
                 continue;
             }
 
             /* NULL character. */
             if(ch == _T('\0')) {
                 PUSH_MARK(ch, off, off+1, MD_MARK_RESOLVED);
                 off++;
                 continue;
             }
 
             off++;
         }
     }
 
     /* Add a dummy mark at the end of the mark vector to simplify
      * process_inlines(). */
     PUSH_MARK(127, ctx->size, ctx->size, MD_MARK_RESOLVED);
 
 abort:
     return ret;
 }
 
 static void
 md_analyze_bracket(MD_CTX* ctx, int mark_index)
 {
     /* We cannot really resolve links here as for that we would need
      * more context. E.g. a following pair of brackets (reference link),
      * or enclosing pair of brackets (if the inner is the link, the outer
      * one cannot be.)
      *
      * Therefore we here only construct a list of '[' ']' pairs ordered by
      * position of the closer. This allows us to analyze what is or is not
      * link in the right order, from inside to outside in case of nested
      * brackets.
      *
      * The resolving itself is deferred to md_resolve_links().
      */
 
     MD_MARK* mark = &ctx->marks[mark_index];
 
     if(mark->flags & MD_MARK_POTENTIAL_OPENER) {
         if(BRACKET_OPENERS.head != -1)
             ctx->marks[BRACKET_OPENERS.tail].flags |= MD_MARK_HASNESTEDBRACKETS;
 
         md_mark_chain_append(ctx, &BRACKET_OPENERS, mark_index);
         return;
     }
 
     if(BRACKET_OPENERS.tail >= 0) {
         /* Pop the opener from the chain. */
         int opener_index = BRACKET_OPENERS.tail;
         MD_MARK* opener = &ctx->marks[opener_index];
         if(opener->prev >= 0)
             ctx->marks[opener->prev].next = -1;
         else
             BRACKET_OPENERS.head = -1;
         BRACKET_OPENERS.tail = opener->prev;
 
         /* Interconnect the opener and closer. */
         opener->next = mark_index;
         mark->prev = opener_index;
 
         /* Add the pair into chain of potential links for md_resolve_links().
          * Note we misuse opener->prev for this as opener->next points to its
          * closer. */
         if(ctx->unresolved_link_tail >= 0)
             ctx->marks[ctx->unresolved_link_tail].prev = opener_index;
         else
             ctx->unresolved_link_head = opener_index;
         ctx->unresolved_link_tail = opener_index;
         opener->prev = -1;
     }
 }
 
 /* Forward declaration. */
 static void md_analyze_link_contents(MD_CTX* ctx, const MD_LINE* lines, int n_lines,
                                      int mark_beg, int mark_end);
 
 static int
 md_resolve_links(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
 {
     int opener_index = ctx->unresolved_link_head;
     OFF last_link_beg = 0;
     OFF last_link_end = 0;
     OFF last_img_beg = 0;
     OFF last_img_end = 0;
 
     while(opener_index >= 0) {
         MD_MARK* opener = &ctx->marks[opener_index];
         int closer_index = opener->next;
         MD_MARK* closer = &ctx->marks[closer_index];
         int next_index = opener->prev;
         MD_MARK* next_opener;
         MD_MARK* next_closer;
         MD_LINK_ATTR attr;
         int is_link = FALSE;
 
         if(next_index >= 0) {
             next_opener = &ctx->marks[next_index];
             next_closer = &ctx->marks[next_opener->next];
         } else {
             next_opener = NULL;
             next_closer = NULL;
         }
 
         /* If nested ("[ [ ] ]"), we need to make sure that:
          *   - The outer does not end inside of (...) belonging to the inner.
          *   - The outer cannot be link if the inner is link (i.e. not image).
          *
          * (Note we here analyze from inner to outer as the marks are ordered
          * by closer->beg.)
          */
         if((opener->beg < last_link_beg  &&  closer->end < last_link_end)  ||
            (opener->beg < last_img_beg  &&  closer->end < last_img_end)  ||
            (opener->beg < last_link_end  &&  opener->ch == '['))
         {
             opener_index = next_index;
             continue;
         }
 
         /* Recognize and resolve wiki links.
          * Wiki-links maybe '[[destination]]' or '[[destination|label]]'.
          */
         if ((ctx->parser.flags & MD_FLAG_WIKILINKS) &&
             (opener->end - opener->beg == 1) &&         /* not image */
             next_opener != NULL &&                      /* double '[' opener */
             next_opener->ch == '[' &&
             (next_opener->beg == opener->beg - 1) &&
             (next_opener->end - next_opener->beg == 1) &&
             next_closer != NULL &&                      /* double ']' closer */
             next_closer->ch == ']' &&
             (next_closer->beg == closer->beg + 1) &&
             (next_closer->end - next_closer->beg == 1))
         {
             MD_MARK* delim = NULL;
             int delim_index;
             OFF dest_beg, dest_end;
 
             is_link = TRUE;
 
             /* We don't allow destination to be longer than 100 characters.
              * Lets scan to see whether there is '|'. (If not then the whole
              * wiki-link has to be below the 100 characters.) */
             delim_index = opener_index + 1;
             while(delim_index < closer_index) {
                 MD_MARK* m = &ctx->marks[delim_index];
                 if(m->ch == '|') {
                     delim = m;
                     break;
                 }
                 if(m->ch != 'D'  &&  m->beg - opener->end > 100)
                     break;
                 delim_index++;
             }
             dest_beg = opener->end;
             dest_end = (delim != NULL) ? delim->beg : closer->beg;
             if(dest_end - dest_beg == 0 || dest_end - dest_beg > 100)
                 is_link = FALSE;
 
             /* There may not be any new line in the destination. */
             if(is_link) {
                 OFF off;
                 for(off = dest_beg; off < dest_end; off++) {
                     if(ISNEWLINE(off)) {
                         is_link = FALSE;
                         break;
                     }
                 }
             }
 
             if(is_link) {
                 if(delim != NULL) {
                     if(delim->end < closer->beg) {
                         md_rollback(ctx, opener_index, delim_index, MD_ROLLBACK_ALL);
                         md_rollback(ctx, delim_index, closer_index, MD_ROLLBACK_CROSSING);
                         delim->flags |= MD_MARK_RESOLVED;
                         opener->end = delim->beg;
                     } else {
                         /* The pipe is just before the closer: [[foo|]] */
                         md_rollback(ctx, opener_index, closer_index, MD_ROLLBACK_ALL);
                         closer->beg = delim->beg;
                         delim = NULL;
                     }
                 }
 
                 opener->beg = next_opener->beg;
                 opener->next = closer_index;
                 opener->flags |= MD_MARK_OPENER | MD_MARK_RESOLVED;
 
                 closer->end = next_closer->end;
                 closer->prev = opener_index;
                 closer->flags |= MD_MARK_CLOSER | MD_MARK_RESOLVED;
 
                 last_link_beg = opener->beg;
                 last_link_end = closer->end;
 
                 if(delim != NULL)
                     md_analyze_link_contents(ctx, lines, n_lines, delim_index+1, closer_index);
 
                 opener_index = next_opener->prev;
                 continue;
             }
         }
 
         if(next_opener != NULL  &&  next_opener->beg == closer->end) {
             if(next_closer->beg > closer->end + 1) {
                 /* Might be full reference link. */
                 if(!(next_opener->flags & MD_MARK_HASNESTEDBRACKETS))
                     is_link = md_is_link_reference(ctx, lines, n_lines, next_opener->beg, next_closer->end, &attr);
             } else {
                 /* Might be shortcut reference link. */
                 if(!(opener->flags & MD_MARK_HASNESTEDBRACKETS))
                     is_link = md_is_link_reference(ctx, lines, n_lines, opener->beg, closer->end, &attr);
             }
 
             if(is_link < 0)
                 return -1;
 
             if(is_link) {
                 /* Eat the 2nd "[...]". */
                 closer->end = next_closer->end;
 
                 /* Do not analyze the label as a standalone link in the next
                  * iteration. */
                 next_index = ctx->marks[next_index].prev;
             }
         } else {
             if(closer->end < ctx->size  &&  CH(closer->end) == _T('(')) {
                 /* Might be inline link. */
                 OFF inline_link_end = UINT_MAX;
 
                 is_link = md_is_inline_link_spec(ctx, lines, n_lines, closer->end, &inline_link_end, &attr);
                 if(is_link < 0)
                     return -1;
 
                 /* Check the closing ')' is not inside an already resolved range
                  * (i.e. a range with a higher priority), e.g. a code span. */
                 if(is_link) {
                     int i = closer_index + 1;
 
                     while(i < ctx->n_marks) {
                         MD_MARK* mark = &ctx->marks[i];
 
                         if(mark->beg >= inline_link_end)
                             break;
                         if((mark->flags & (MD_MARK_OPENER | MD_MARK_RESOLVED)) == (MD_MARK_OPENER | MD_MARK_RESOLVED)) {
                             if(ctx->marks[mark->next].beg >= inline_link_end) {
                                 /* Cancel the link status. */
                                 if(attr.title_needs_free)
                                     free(attr.title);
                                 is_link = FALSE;
                                 break;
                             }
 
                             i = mark->next + 1;
                         } else {
                             i++;
                         }
                     }
                 }
 
                 if(is_link) {
                     /* Eat the "(...)" */
                     closer->end = inline_link_end;
                 }
             }
 
             if(!is_link) {
                 /* Might be collapsed reference link. */
                 if(!(opener->flags & MD_MARK_HASNESTEDBRACKETS))
                     is_link = md_is_link_reference(ctx, lines, n_lines, opener->beg, closer->end, &attr);
                 if(is_link < 0)
                     return -1;
             }
         }
 
         if(is_link) {
             /* Resolve the brackets as a link. */
             opener->flags |= MD_MARK_OPENER | MD_MARK_RESOLVED;
             closer->flags |= MD_MARK_CLOSER | MD_MARK_RESOLVED;
 
             /* If it is a link, we store the destination and title in the two
              * dummy marks after the opener. */
             MD_ASSERT(ctx->marks[opener_index+1].ch == 'D');
             ctx->marks[opener_index+1].beg = attr.dest_beg;
             ctx->marks[opener_index+1].end = attr.dest_end;
 
             MD_ASSERT(ctx->marks[opener_index+2].ch == 'D');
             md_mark_store_ptr(ctx, opener_index+2, attr.title);
             /* The title might or might not have been allocated for us. */
             if(attr.title_needs_free)
                 md_mark_chain_append(ctx, &PTR_CHAIN, opener_index+2);
             ctx->marks[opener_index+2].prev = attr.title_size;
 
             if(opener->ch == '[') {
                 last_link_beg = opener->beg;
                 last_link_end = closer->end;
             } else {
                 last_img_beg = opener->beg;
                 last_img_end = closer->end;
             }
 
             md_analyze_link_contents(ctx, lines, n_lines, opener_index+1, closer_index);
 
             /* If the link text is formed by nothing but permissive autolink,
              * suppress the autolink.
              * See https://github.com/mity/md4c/issues/152 for more info. */
             if(ctx->parser.flags & MD_FLAG_PERMISSIVEAUTOLINKS) {
                 MD_MARK* first_nested;
                 MD_MARK* last_nested;
 
                 first_nested = opener + 1;
                 while(first_nested->ch == _T('D')  &&  first_nested < closer)
                     first_nested++;
 
                 last_nested = closer - 1;
                 while(first_nested->ch == _T('D')  &&  last_nested > opener)
                     last_nested--;
 
                 if((first_nested->flags & MD_MARK_RESOLVED)  &&
                    first_nested->beg == opener->end  &&
                    ISANYOF_(first_nested->ch, _T("@:."))  &&
                    first_nested->next == (last_nested - ctx->marks)  &&
                    last_nested->end == closer->beg)
                 {
                     first_nested->ch = _T('D');
                     first_nested->flags &= ~MD_MARK_RESOLVED;
                     last_nested->ch = _T('D');
                     last_nested->flags &= ~MD_MARK_RESOLVED;
                 }
             }
         }
 
         opener_index = next_index;
     }
 
     return 0;
 }
 
 /* Analyze whether the mark '&' starts a HTML entity.
  * If so, update its flags as well as flags of corresponding closer ';'. */
 static void
 md_analyze_entity(MD_CTX* ctx, int mark_index)
 {
     MD_MARK* opener = &ctx->marks[mark_index];
     MD_MARK* closer;
     OFF off;
 
     /* Cannot be entity if there is no closer as the next mark.
      * (Any other mark between would mean strange character which cannot be
      * part of the entity.
      *
      * So we can do all the work on '&' and do not call this later for the
      * closing mark ';'.
      */
     if(mark_index + 1 >= ctx->n_marks)
         return;
     closer = &ctx->marks[mark_index+1];
     if(closer->ch != ';')
         return;
 
     if(md_is_entity(ctx, opener->beg, closer->end, &off)) {
         MD_ASSERT(off == closer->end);
 
         md_resolve_range(ctx, NULL, mark_index, mark_index+1);
         opener->end = closer->end;
     }
 }
 
 static void
 md_analyze_table_cell_boundary(MD_CTX* ctx, int mark_index)
 {
     MD_MARK* mark = &ctx->marks[mark_index];
     mark->flags |= MD_MARK_RESOLVED;
 
     md_mark_chain_append(ctx, &TABLECELLBOUNDARIES, mark_index);
     ctx->n_table_cell_boundaries++;
 }
 
 /* Split a longer mark into two. The new mark takes the given count of
  * characters. May only be called if an adequate number of dummy 'D' marks
  * follows.
  */
 static int
 md_split_emph_mark(MD_CTX* ctx, int mark_index, SZ n)
 {
     MD_MARK* mark = &ctx->marks[mark_index];
     int new_mark_index = mark_index + (mark->end - mark->beg - n);
     MD_MARK* dummy = &ctx->marks[new_mark_index];
 
     MD_ASSERT(mark->end - mark->beg > n);
     MD_ASSERT(dummy->ch == 'D');
 
     memcpy(dummy, mark, sizeof(MD_MARK));
     mark->end -= n;
     dummy->beg = mark->end;
 
     return new_mark_index;
 }
 
 static void
 md_analyze_emph(MD_CTX* ctx, int mark_index)
 {
     MD_MARK* mark = &ctx->marks[mark_index];
     MD_MARKCHAIN* chain = md_mark_chain(ctx, mark_index);
 
     /* If we can be a closer, try to resolve with the preceding opener. */
     if(mark->flags & MD_MARK_POTENTIAL_CLOSER) {
         MD_MARK* opener = NULL;
         int opener_index = 0;
 
         if(mark->ch == _T('*')) {
             MD_MARKCHAIN* opener_chains[6];
             int i, n_opener_chains;
             unsigned flags = mark->flags;
 
             /* Apply the "rule of three". */
             n_opener_chains = 0;
             opener_chains[n_opener_chains++] = &ASTERISK_OPENERS_intraword_mod3_0;
             if((flags & MD_MARK_EMPH_MOD3_MASK) != MD_MARK_EMPH_MOD3_2)
                 opener_chains[n_opener_chains++] = &ASTERISK_OPENERS_intraword_mod3_1;
             if((flags & MD_MARK_EMPH_MOD3_MASK) != MD_MARK_EMPH_MOD3_1)
                 opener_chains[n_opener_chains++] = &ASTERISK_OPENERS_intraword_mod3_2;
             opener_chains[n_opener_chains++] = &ASTERISK_OPENERS_extraword_mod3_0;
             if(!(flags & MD_MARK_EMPH_INTRAWORD)  ||  (flags & MD_MARK_EMPH_MOD3_MASK) != MD_MARK_EMPH_MOD3_2)
                 opener_chains[n_opener_chains++] = &ASTERISK_OPENERS_extraword_mod3_1;
             if(!(flags & MD_MARK_EMPH_INTRAWORD)  ||  (flags & MD_MARK_EMPH_MOD3_MASK) != MD_MARK_EMPH_MOD3_1)
                 opener_chains[n_opener_chains++] = &ASTERISK_OPENERS_extraword_mod3_2;
 
             /* Opener is the most recent mark from the allowed chains. */
             for(i = 0; i < n_opener_chains; i++) {
                 if(opener_chains[i]->tail >= 0) {
                     int tmp_index = opener_chains[i]->tail;
                     MD_MARK* tmp_mark = &ctx->marks[tmp_index];
                     if(opener == NULL  ||  tmp_mark->end > opener->end) {
                         opener_index = tmp_index;
                         opener = tmp_mark;
                     }
                 }
             }
         } else {
             /* Simple emph. mark */
             if(chain->tail >= 0) {
                 opener_index = chain->tail;
                 opener = &ctx->marks[opener_index];
             }
         }
 
         /* Resolve, if we have found matching opener. */
         if(opener != NULL) {
             SZ opener_size = opener->end - opener->beg;
             SZ closer_size = mark->end - mark->beg;
             MD_MARKCHAIN* opener_chain = md_mark_chain(ctx, opener_index);
 
             if(opener_size > closer_size) {
                 opener_index = md_split_emph_mark(ctx, opener_index, closer_size);
                 md_mark_chain_append(ctx, opener_chain, opener_index);
             } else if(opener_size < closer_size) {
                 md_split_emph_mark(ctx, mark_index, closer_size - opener_size);
             }
 
             md_rollback(ctx, opener_index, mark_index, MD_ROLLBACK_CROSSING);
             md_resolve_range(ctx, opener_chain, opener_index, mark_index);
             return;
         }
     }
 
     /* If we could not resolve as closer, we may be yet be an opener. */
     if(mark->flags & MD_MARK_POTENTIAL_OPENER)
         md_mark_chain_append(ctx, chain, mark_index);
 }
 
 static void
 md_analyze_tilde(MD_CTX* ctx, int mark_index)
 {
     MD_MARK* mark = &ctx->marks[mark_index];
     MD_MARKCHAIN* chain = md_mark_chain(ctx, mark_index);
 
     /* We attempt to be Github Flavored Markdown compatible here. GFM accepts
      * only tildes sequences of length 1 and 2, and the length of the opener
      * and closer has to match. */
 
     if((mark->flags & MD_MARK_POTENTIAL_CLOSER)  &&  chain->head >= 0) {
         int opener_index = chain->head;
 
         md_rollback(ctx, opener_index, mark_index, MD_ROLLBACK_CROSSING);
         md_resolve_range(ctx, chain, opener_index, mark_index);
         return;
     }
 
     if(mark->flags & MD_MARK_POTENTIAL_OPENER)
         md_mark_chain_append(ctx, chain, mark_index);
 }
 
 static void
 md_analyze_dollar(MD_CTX* ctx, int mark_index)
 {
     /* This should mimic the way inline equations work in LaTeX, so there
      * can only ever be one item in the chain (i.e. the dollars can't be
      * nested). This is basically the same as the md_analyze_tilde function,
      * except that we require matching openers and closers to be of the same
      * length.
      *
      * E.g.: $abc$$def$$ => abc (display equation) def (end equation) */
     if(DOLLAR_OPENERS.head >= 0) {
         /* If the potential closer has a non-matching number of $, discard */
         MD_MARK* open = &ctx->marks[DOLLAR_OPENERS.head];
         MD_MARK* close = &ctx->marks[mark_index];
 
         int opener_index = DOLLAR_OPENERS.head;
         md_rollback(ctx, opener_index, mark_index, MD_ROLLBACK_ALL);
         if (open->end - open->beg == close->end - close->beg) {
             /* We are the matching closer */
             md_resolve_range(ctx, &DOLLAR_OPENERS, opener_index, mark_index);
             return;
         }
     }
 
     md_mark_chain_append(ctx, &DOLLAR_OPENERS, mark_index);
 }
 
 static void
 md_analyze_permissive_url_autolink(MD_CTX* ctx, int mark_index)
 {
     MD_MARK* opener = &ctx->marks[mark_index];
     int closer_index = mark_index + 1;
     MD_MARK* closer = &ctx->marks[closer_index];
     MD_MARK* next_resolved_mark;
     OFF off = opener->end;
     int n_dots = FALSE;
     int has_underscore_in_last_seg = FALSE;
     int has_underscore_in_next_to_last_seg = FALSE;
     int n_opened_parenthesis = 0;
     int n_excess_parenthesis = 0;
 
     /* Check for domain. */
     while(off < ctx->size) {
         if(ISALNUM(off) || CH(off) == _T('-')) {
             off++;
         } else if(CH(off) == _T('.')) {
             /* We must see at least one period. */
             n_dots++;
             has_underscore_in_next_to_last_seg = has_underscore_in_last_seg;
             has_underscore_in_last_seg = FALSE;
             off++;
         } else if(CH(off) == _T('_')) {
             /* No underscore may be present in the last two domain segments. */
             has_underscore_in_last_seg = TRUE;
             off++;
         } else {
             break;
         }
     }
     if(off > opener->end  &&  CH(off-1) == _T('.')) {
         off--;
         n_dots--;
     }
     if(off <= opener->end || n_dots == 0 || has_underscore_in_next_to_last_seg || has_underscore_in_last_seg)
         return;
 
     /* Check for path. */
     next_resolved_mark = closer + 1;
     while(next_resolved_mark->ch == 'D' || !(next_resolved_mark->flags & MD_MARK_RESOLVED))
         next_resolved_mark++;
     while(off < next_resolved_mark->beg  &&  CH(off) != _T('<')  &&  !ISWHITESPACE(off)  &&  !ISNEWLINE(off)) {
         /* Parenthesis must be balanced. */
         if(CH(off) == _T('(')) {
             n_opened_parenthesis++;
         } else if(CH(off) == _T(')')) {
             if(n_opened_parenthesis > 0)
                 n_opened_parenthesis--;
             else
                 n_excess_parenthesis++;
         }
 
         off++;
     }
 
     /* Trim a trailing punctuation from the end. */
     while(TRUE) {
         if(ISANYOF(off-1, _T("?!.,:*_~"))) {
             off--;
         } else if(CH(off-1) == ')'  &&  n_excess_parenthesis > 0) {
             /* Unmatched ')' can be in an interior of the path but not at the
              * of it, so the auto-link may be safely nested in a parenthesis
              * pair. */
             off--;
             n_excess_parenthesis--;
         } else {
             break;
         }
     }
 
     /* Ok. Lets call it an auto-link. Adapt opener and create closer to zero
      * length so all the contents becomes the link text. */
     MD_ASSERT(closer->ch == 'D' ||
               ((ctx->parser.flags & MD_FLAG_PERMISSIVEWWWAUTOLINKS) &&
                (closer->ch == '.' || closer->ch == ':' || closer->ch == '@')));
     opener->end = opener->beg;
     closer->ch = opener->ch;
     closer->beg = off;
     closer->end = off;
     md_resolve_range(ctx, NULL, mark_index, closer_index);
 }
 
 /* The permissive autolinks do not have to be enclosed in '<' '>' but we
  * instead impose stricter rules what is understood as an e-mail address
  * here. Actually any non-alphanumeric characters with exception of '.'
  * are prohibited both in username and after '@'. */
 static void
 md_analyze_permissive_email_autolink(MD_CTX* ctx, int mark_index)
 {
     MD_MARK* opener = &ctx->marks[mark_index];
     int closer_index;
     MD_MARK* closer;
     OFF beg = opener->beg;
     OFF end = opener->end;
     int dot_count = 0;
 
     MD_ASSERT(opener->ch == _T('@'));
 
     /* Scan for name before '@'. */
     while(beg > 0  &&  (ISALNUM(beg-1) || ISANYOF(beg-1, _T(".-_+"))))
         beg--;
 
     /* Scan for domain after '@'. */
     while(end < ctx->size  &&  (ISALNUM(end) || ISANYOF(end, _T(".-_")))) {
         if(CH(end) == _T('.'))
             dot_count++;
         end++;
     }
     if(CH(end-1) == _T('.')) {  /* Final '.' not part of it. */
         dot_count--;
         end--;
     }
     else if(ISANYOF2(end-1, _T('-'), _T('_'))) /* These are forbidden at the end. */
         return;
     if(CH(end-1) == _T('@')  ||  dot_count == 0)
         return;
 
     /* Ok. Lets call it auto-link. Adapt opener and create closer to zero
      * length so all the contents becomes the link text. */
     closer_index = mark_index + 1;
     closer = &ctx->marks[closer_index];
     if (closer->ch != 'D') return;
 
     opener->beg = beg;
     opener->end = beg;
     closer->ch = opener->ch;
     closer->beg = end;
     closer->end = end;
     md_resolve_range(ctx, NULL, mark_index, closer_index);
 }
 
 static inline void
 md_analyze_marks(MD_CTX* ctx, const MD_LINE* lines, int n_lines,
                  int mark_beg, int mark_end, const CHAR* mark_chars)
 {
     int i = mark_beg;
     MD_UNUSED(lines);
     MD_UNUSED(n_lines);
 
     while(i < mark_end) {
         MD_MARK* mark = &ctx->marks[i];
 
         /* Skip resolved spans. */
         if(mark->flags & MD_MARK_RESOLVED) {
             if(mark->flags & MD_MARK_OPENER) {
                 MD_ASSERT(i < mark->next);
                 i = mark->next + 1;
             } else {
                 i++;
             }
             continue;
         }
 
         /* Skip marks we do not want to deal with. */
         if(!ISANYOF_(mark->ch, mark_chars)) {
             i++;
             continue;
         }
 
         /* Analyze the mark. */
         switch(mark->ch) {
             case '[':   /* Pass through. */
             case '!':   /* Pass through. */
             case ']':   md_analyze_bracket(ctx, i); break;
             case '&':   md_analyze_entity(ctx, i); break;
             case '|':   md_analyze_table_cell_boundary(ctx, i); break;
             case '_':   /* Pass through. */
             case '*':   md_analyze_emph(ctx, i); break;
             case '~':   md_analyze_tilde(ctx, i); break;
             case '$':   md_analyze_dollar(ctx, i); break;
             case '.':   /* Pass through. */
             case ':':   md_analyze_permissive_url_autolink(ctx, i); break;
             case '@':   md_analyze_permissive_email_autolink(ctx, i); break;
         }
 
         i++;
     }
 }
 
 /* Analyze marks (build ctx->marks). */
 static int
 md_analyze_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines, int table_mode)
 {
     int ret;
 
     /* Reset the previously collected stack of marks. */
     ctx->n_marks = 0;
 
     /* Collect all marks. */
     MD_CHECK(md_collect_marks(ctx, lines, n_lines, table_mode));
 
     /* (1) Links. */
     md_analyze_marks(ctx, lines, n_lines, 0, ctx->n_marks, _T("[]!"));
     MD_CHECK(md_resolve_links(ctx, lines, n_lines));
     BRACKET_OPENERS.head = -1;
     BRACKET_OPENERS.tail = -1;
     ctx->unresolved_link_head = -1;
     ctx->unresolved_link_tail = -1;
 
     if(table_mode) {
         /* (2) Analyze table cell boundaries.
          * Note we reset TABLECELLBOUNDARIES chain prior to the call md_analyze_marks(),
          * not after, because caller may need it. */
         MD_ASSERT(n_lines == 1);
         TABLECELLBOUNDARIES.head = -1;
         TABLECELLBOUNDARIES.tail = -1;
         ctx->n_table_cell_boundaries = 0;
         md_analyze_marks(ctx, lines, n_lines, 0, ctx->n_marks, _T("|"));
         return ret;
     }
 
     /* (3) Emphasis and strong emphasis; permissive autolinks. */
     md_analyze_link_contents(ctx, lines, n_lines, 0, ctx->n_marks);
 
 abort:
     return ret;
 }
 
 static void
 md_analyze_link_contents(MD_CTX* ctx, const MD_LINE* lines, int n_lines,
                          int mark_beg, int mark_end)
 {
     int i;
 
     md_analyze_marks(ctx, lines, n_lines, mark_beg, mark_end, _T("&"));
     md_analyze_marks(ctx, lines, n_lines, mark_beg, mark_end, _T("*_~$@:."));
 
     for(i = OPENERS_CHAIN_FIRST; i <= OPENERS_CHAIN_LAST; i++) {
         ctx->mark_chains[i].head = -1;
         ctx->mark_chains[i].tail = -1;
     }
 }
 
 static int
 md_enter_leave_span_a(MD_CTX* ctx, int enter, MD_SPANTYPE type,
                       const CHAR* dest, SZ dest_size, int prohibit_escapes_in_dest,
                       const CHAR* title, SZ title_size)
 {
     MD_ATTRIBUTE_BUILD href_build = { 0 };
     MD_ATTRIBUTE_BUILD title_build = { 0 };
     MD_SPAN_A_DETAIL det;
     int ret = 0;
 
     /* Note we here rely on fact that MD_SPAN_A_DETAIL and
      * MD_SPAN_IMG_DETAIL are binary-compatible. */
     memset(&det, 0, sizeof(MD_SPAN_A_DETAIL));
     MD_CHECK(md_build_attribute(ctx, dest, dest_size,
                     (prohibit_escapes_in_dest ? MD_BUILD_ATTR_NO_ESCAPES : 0),
                     &det.href, &href_build));
     MD_CHECK(md_build_attribute(ctx, title, title_size, 0, &det.title, &title_build));
 
     if(enter)
         MD_ENTER_SPAN(type, &det);
     else
         MD_LEAVE_SPAN(type, &det);
 
 abort:
     md_free_attribute(ctx, &href_build);
     md_free_attribute(ctx, &title_build);
     return ret;
 }
 
 static int
 md_enter_leave_span_wikilink(MD_CTX* ctx, int enter, const CHAR* target, SZ target_size)
 {
     MD_ATTRIBUTE_BUILD target_build = { 0 };
     MD_SPAN_WIKILINK_DETAIL det;
     int ret = 0;
 
     memset(&det, 0, sizeof(MD_SPAN_WIKILINK_DETAIL));
     MD_CHECK(md_build_attribute(ctx, target, target_size, 0, &det.target, &target_build));
 
     if (enter)
         MD_ENTER_SPAN(MD_SPAN_WIKILINK, &det);
     else
         MD_LEAVE_SPAN(MD_SPAN_WIKILINK, &det);
 
 abort:
     md_free_attribute(ctx, &target_build);
     return ret;
 }
 
 
 /* Render the output, accordingly to the analyzed ctx->marks. */
 static int
 md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
 {
     MD_TEXTTYPE text_type;
     const MD_LINE* line = lines;
     MD_MARK* prev_mark = NULL;
     MD_MARK* mark;
     OFF off = lines[0].beg;
     OFF end = lines[n_lines-1].end;
     int enforce_hardbreak = 0;
     int ret = 0;
 
     /* Find first resolved mark. Note there is always at least one resolved
      * mark,  the dummy last one after the end of the latest line we actually
      * never really reach. This saves us of a lot of special checks and cases
      * in this function. */
     mark = ctx->marks;
     while(!(mark->flags & MD_MARK_RESOLVED))
         mark++;
 
     text_type = MD_TEXT_NORMAL;
 
     while(1) {
         /* Process the text up to the next mark or end-of-line. */
         OFF tmp = (line->end < mark->beg ? line->end : mark->beg);
         if(tmp > off) {
             MD_TEXT(text_type, STR(off), tmp - off);
             off = tmp;
         }
 
         /* If reached the mark, process it and move to next one. */
         if(off >= mark->beg) {
             switch(mark->ch) {
                 case '\\':      /* Backslash escape. */
                     if(ISNEWLINE(mark->beg+1))
                         enforce_hardbreak = 1;
                     else
                         MD_TEXT(text_type, STR(mark->beg+1), 1);
                     break;
 
                 case ' ':       /* Non-trivial space. */
                     MD_TEXT(text_type, _T(" "), 1);
                     break;
 
                 case '`':       /* Code span. */
                     if(mark->flags & MD_MARK_OPENER) {
                         MD_ENTER_SPAN(MD_SPAN_CODE, NULL);
                         text_type = MD_TEXT_CODE;
                     } else {
                         MD_LEAVE_SPAN(MD_SPAN_CODE, NULL);
                         text_type = MD_TEXT_NORMAL;
                     }
                     break;
 
                 case '-': /* faint */
                     if(mark->flags & MD_MARK_OPENER) {
                         MD_ENTER_SPAN(MD_SPAN_FNT, NULL);
                     } else {
                         MD_LEAVE_SPAN(MD_SPAN_FNT, NULL);
                     }
                     break;
 
                 case '%': /* inverse */
                     if(mark->flags & MD_MARK_OPENER) {
                         MD_ENTER_SPAN(MD_SPAN_INV, NULL);
                     } else {
                         MD_LEAVE_SPAN(MD_SPAN_INV, NULL);
                     }
                     break;
 
                 case '^': /* blink */
                     if(mark->flags & MD_MARK_OPENER) {
                         MD_ENTER_SPAN(MD_SPAN_BLI, NULL);
                     } else {
                         MD_LEAVE_SPAN(MD_SPAN_BLI, NULL);
                     }
                     break;
 
                 case '_':       /* Underline (or emphasis if we fall through). */
                     if(ctx->parser.flags & MD_FLAG_UNDERLINE) {
                         if(mark->flags & MD_MARK_OPENER) {
                             /* while(off < mark->end) { */
                             /*     MD_ENTER_SPAN(MD_SPAN_U, NULL); */
                             /*     off++; */
                             /* } */
                             if((mark->end - off) % 2) {
                                 MD_ENTER_SPAN(MD_SPAN_U, NULL);
                                 off++;
                             }
                             while(off + 1 < mark->end) {
                                 MD_ENTER_SPAN(MD_SPAN_STRONG, NULL);
                                 off += 2;
                             }
                         } else {
                             /* while(off < mark->end) { */
                             /*     MD_LEAVE_SPAN(MD_SPAN_U, NULL); */
                             /*     off++; */
                             /* } */
                             while(off + 1 < mark->end) {
                                 MD_LEAVE_SPAN(MD_SPAN_STRONG, NULL);
                                 off += 2;
                             }
                             if((mark->end - off) % 2) {
                                 MD_LEAVE_SPAN(MD_SPAN_U, NULL);
                                 off++;
                             }
                         }
                         break;
                     }
                     MD_FALLTHROUGH();
 
                 case '*':       /* Emphasis, strong emphasis. */
                     if(mark->flags & MD_MARK_OPENER) {
                         if((mark->end - off) % 2) {
                             MD_ENTER_SPAN(MD_SPAN_EM, NULL);
                             off++;
                         }
                         while(off + 1 < mark->end) {
                             MD_ENTER_SPAN(MD_SPAN_STRONG, NULL);
                             off += 2;
                         }
                     } else {
                         while(off + 1 < mark->end) {
                             MD_LEAVE_SPAN(MD_SPAN_STRONG, NULL);
                             off += 2;
                         }
                         if((mark->end - off) % 2) {
                             MD_LEAVE_SPAN(MD_SPAN_EM, NULL);
                             off++;
                         }
                     }
                     break;
 
                 case '~': /* crossed */
                     if(mark->flags & MD_MARK_OPENER)
                         MD_ENTER_SPAN(MD_SPAN_DEL, NULL);
                     else
                         MD_LEAVE_SPAN(MD_SPAN_DEL, NULL);
                     break;
 
                 case '$':
                     if(mark->flags & MD_MARK_OPENER) {
                         MD_ENTER_SPAN((mark->end - off) % 2 ? MD_SPAN_LATEXMATH : MD_SPAN_LATEXMATH_DISPLAY, NULL);
                         text_type = MD_TEXT_LATEXMATH;
                     } else {
                         MD_LEAVE_SPAN((mark->end - off) % 2 ? MD_SPAN_LATEXMATH : MD_SPAN_LATEXMATH_DISPLAY, NULL);
                         text_type = MD_TEXT_NORMAL;
                     }
                     break;
 
                 case '!': /* conceal/hidden */
                     if (mark->prev == -1) {
                         if (mark->flags & MD_MARK_OPENER) {
                             MD_ENTER_SPAN(MD_SPAN_COC, NULL);
                             break;
                         }
                     }
                     else {
                         if (ctx->marks[mark->prev].ch == '!' && !(mark->flags & MD_MARK_OPENER)) {
                             MD_LEAVE_SPAN(MD_SPAN_COC, NULL);
                             break;
                         }
                     }
                 case '[':       /* Link, wiki link, image, anchor. */
                 case ']':
                 {
                     const MD_MARK* opener = (mark->ch != ']' ? mark : &ctx->marks[mark->prev]);
                     const MD_MARK* closer = &ctx->marks[opener->next];
                     const MD_MARK* dest_mark;
                     const MD_MARK* title_mark;
 
                     if ((opener->ch == '[' && closer->ch == ']') &&
                         opener->end - opener->beg >= 2 &&
                         closer->end - closer->beg >= 2)
                     {
                         int has_label = (opener->end - opener->beg > 2);
                         SZ target_sz;
 
                         if(has_label)
                             target_sz = opener->end - (opener->beg+2);
                         else
                             target_sz = closer->beg - opener->end;
 
                         MD_CHECK(md_enter_leave_span_wikilink(ctx, (mark->ch != ']'),
                                  has_label ? STR(opener->beg+2) : STR(opener->end),
                                  target_sz));
 
                         break;
                     }
 
                     if ((opener->ch == '[' && closer->ch == ']') &&
                         opener->end - opener->beg == 2 &&
                         closer->end - closer->beg == 1 &&
                         CH(opener->beg+1) == _T('|'))
                     {
                         if(mark->flags & MD_MARK_OPENER) {
                             MD_ENTER_SPAN(MD_SPAN_ANCHOR, NULL);
                         } else {
                             MD_LEAVE_SPAN(MD_SPAN_ANCHOR, NULL);
                         }
                     }
 
                     dest_mark = opener+1;
                     MD_ASSERT(dest_mark->ch == 'D');
                     title_mark = opener+2;
                     if (title_mark->ch != 'D') break;
 
                     MD_CHECK(md_enter_leave_span_a(ctx, (mark->ch != ']'),
                                 (opener->ch == '!' ? MD_SPAN_IMG : MD_SPAN_A),
                                 STR(dest_mark->beg), dest_mark->end - dest_mark->beg, FALSE,
                                 md_mark_get_ptr(ctx, (int)(title_mark - ctx->marks)),
 								title_mark->prev));
 
                     /* link/image closer may span multiple lines. */
                     if(mark->ch == ']') {
                         while(mark->end > line->end)
                             line++;
                     }
 
                     break;
                 }
 
                 case '<':
                 case '>':       /* Autolink or raw HTML. */
                     if(!(mark->flags & MD_MARK_AUTOLINK)) {
                         /* Raw HTML. */
                         if(mark->flags & MD_MARK_OPENER)
                             text_type = MD_TEXT_HTML;
                         else
                             text_type = MD_TEXT_NORMAL;
                         break;
                     }
                     /* Pass through, if auto-link. */
                     MD_FALLTHROUGH();
 
                 case '@':       /* Permissive e-mail autolink. */
                 case ':':       /* Permissive URL autolink. */
                 case '.':       /* Permissive WWW autolink. */
                 {
                     MD_MARK* opener = ((mark->flags & MD_MARK_OPENER) ? mark : &ctx->marks[mark->prev]);
                     MD_MARK* closer = &ctx->marks[opener->next];
                     const CHAR* dest = STR(opener->end);
                     SZ dest_size = closer->beg - opener->end;
 
                     /* For permissive auto-links we do not know closer mark
                      * position at the time of md_collect_marks(), therefore
                      * it can be out-of-order in ctx->marks[].
                      *
                      * With this flag, we make sure that we output the closer
                      * only if we processed the opener. */
                     if(mark->flags & MD_MARK_OPENER)
                         closer->flags |= MD_MARK_VALIDPERMISSIVEAUTOLINK;
 
                     if(opener->ch == '@' || opener->ch == '.') {
                         dest_size += 7;
                         MD_TEMP_BUFFER(dest_size * sizeof(CHAR));
                         memcpy(ctx->buffer,
                                 (opener->ch == '@' ? _T("mailto:") : _T("http://")),
                                 7 * sizeof(CHAR));
                         memcpy(ctx->buffer + 7, dest, (dest_size-7) * sizeof(CHAR));
                         dest = ctx->buffer;
                     }
 
                     if(closer->flags & MD_MARK_VALIDPERMISSIVEAUTOLINK)
                         MD_CHECK(md_enter_leave_span_a(ctx, (mark->flags & MD_MARK_OPENER),
                                     MD_SPAN_A, dest, dest_size, TRUE, NULL, 0));
                     break;
                 }
 
                 case '&':       /* Entity. */
                     MD_TEXT(MD_TEXT_ENTITY, STR(mark->beg), mark->end - mark->beg);
                     break;
 
                 case '\0':
                     MD_TEXT(MD_TEXT_NULLCHAR, _T(""), 1);
                     break;
 
                 case 127:
                     goto abort;
             }
 
             off = mark->end;
 
             /* Move to next resolved mark. */
             prev_mark = mark;
             mark++;
             while(!(mark->flags & MD_MARK_RESOLVED)  ||  mark->beg < off)
                 mark++;
         }
 
         /* If reached end of line, move to next one. */
         if(off >= line->end) {
             /* If it is the last line, we are done. */
             if(off >= end)
                 break;
 
             if(text_type == MD_TEXT_CODE || text_type == MD_TEXT_LATEXMATH) {
                 OFF tmp;
 
                 MD_ASSERT(prev_mark != NULL);
                 MD_ASSERT(ISANYOF2_(prev_mark->ch, '`', '$')  &&  (prev_mark->flags & MD_MARK_OPENER));
                 MD_ASSERT(ISANYOF2_(mark->ch, '`', '$')  &&  (mark->flags & MD_MARK_CLOSER));
 
                 /* Inside a code span, trailing line whitespace has to be
                  * outputted. */
                 tmp = off;
                 while(off < ctx->size  &&  ISBLANK(off))
                     off++;
                 if(off > tmp)
                     MD_TEXT(text_type, STR(tmp), off-tmp);
 
                 /* and new lines are transformed into single spaces. */
                 if(prev_mark->end < off  &&  off < mark->beg)
                     MD_TEXT(text_type, _T(" "), 1);
             } else if(text_type == MD_TEXT_HTML) {
                 /* Inside raw HTML, we output the new line verbatim, including
                  * any trailing spaces. */
                 OFF tmp = off;
 
                 while(tmp < end  &&  ISBLANK(tmp))
                     tmp++;
                 if(tmp > off)
                     MD_TEXT(MD_TEXT_HTML, STR(off), tmp - off);
                 MD_TEXT(MD_TEXT_HTML, _T("\n"), 1);
             } else {
                 /* Output soft or hard line break. */
                 MD_TEXTTYPE break_type = MD_TEXT_SOFTBR;
 
                 if(text_type == MD_TEXT_NORMAL) {
                     if(enforce_hardbreak)
                         break_type = MD_TEXT_BR;
                     else if((CH(line->end) == _T(' ') && CH(line->end+1) == _T(' ')))
                         break_type = MD_TEXT_BR;
                 }
 
                 MD_TEXT(break_type, _T("\n"), 1);
             }
 
             /* Move to the next line. */
             line++;
             off = line->beg;
 
             enforce_hardbreak = 0;
         }
     }
 
 abort:
     return ret;
 }
 
 
 /***************************
  ***  Processing Tables  ***
  ***************************/
 
 static void
 md_analyze_table_alignment(MD_CTX* ctx, OFF beg, OFF end, MD_ALIGN* align, int n_align)
 {
     static const MD_ALIGN align_map[] = { MD_ALIGN_DEFAULT, MD_ALIGN_LEFT, MD_ALIGN_RIGHT, MD_ALIGN_CENTER };
     OFF off = beg;
 
     while(n_align > 0) {
         int index = 0;  /* index into align_map[] */
 
         while(CH(off) != _T('-'))
             off++;
         if(off > beg  &&  CH(off-1) == _T(':'))
             index |= 1;
         while(off < end  &&  CH(off) == _T('-'))
             off++;
         if(off < end  &&  CH(off) == _T(':'))
             index |= 2;
 
         *align = align_map[index];
         align++;
         n_align--;
     }
 
 }
 
 /* Forward declaration. */
 static int md_process_normal_block_contents(MD_CTX* ctx, const MD_LINE* lines, int n_lines);
 
 static int
 md_process_table_cell(MD_CTX* ctx, MD_BLOCKTYPE cell_type, MD_ALIGN align, OFF beg, OFF end)
 {
     MD_LINE line;
     MD_BLOCK_TD_DETAIL det;
     int ret = 0;
 
     while(beg < end  &&  ISWHITESPACE(beg))
         beg++;
     while(end > beg  &&  ISWHITESPACE(end-1))
         end--;
 
     det.align = align;
     line.beg = beg;
     line.end = end;
 
     MD_ENTER_BLOCK(cell_type, &det);
     MD_CHECK(md_process_normal_block_contents(ctx, &line, 1));
     MD_LEAVE_BLOCK(cell_type, &det);
 
 abort:
     return ret;
 }
 
 static int
 md_process_table_row(MD_CTX* ctx, MD_BLOCKTYPE cell_type, OFF beg, OFF end,
                      const MD_ALIGN* align, int col_count)
 {
     MD_LINE line;
     OFF* pipe_offs = NULL;
     int i, j, k, n;
     int ret = 0;
 
     line.beg = beg;
     line.end = end;
 
     /* Break the line into table cells by identifying pipe characters who
      * form the cell boundary. */
     MD_CHECK(md_analyze_inlines(ctx, &line, 1, TRUE));
 
     /* We have to remember the cell boundaries in local buffer because
      * ctx->marks[] shall be reused during cell contents processing. */
     n = ctx->n_table_cell_boundaries + 2;
     pipe_offs = (OFF*) malloc(n * sizeof(OFF));
     if(pipe_offs == NULL) {
         MD_LOG("malloc() failed.");
         ret = -1;
         goto abort;
     }
     j = 0;
     pipe_offs[j++] = beg;
     for(i = TABLECELLBOUNDARIES.head; i >= 0; i = ctx->marks[i].next) {
         MD_MARK* mark = &ctx->marks[i];
         pipe_offs[j++] = mark->end;
     }
     pipe_offs[j++] = end+1;
 
     /* Process cells. */
     MD_ENTER_BLOCK(MD_BLOCK_TR, NULL);
     k = 0;
     for(i = 0; i < j-1  &&  k < col_count; i++) {
         if(pipe_offs[i] < pipe_offs[i+1]-1)
             MD_CHECK(md_process_table_cell(ctx, cell_type, align[k++], pipe_offs[i], pipe_offs[i+1]-1));
     }
     /* Make sure we call enough table cells even if the current table contains
      * too few of them. */
     while(k < col_count)
         MD_CHECK(md_process_table_cell(ctx, cell_type, align[k++], 0, 0));
     MD_LEAVE_BLOCK(MD_BLOCK_TR, NULL);
 
 abort:
     free(pipe_offs);
 
     /* Free any temporary memory blocks stored within some dummy marks. */
     for(i = PTR_CHAIN.head; i >= 0; i = ctx->marks[i].next)
         free(md_mark_get_ptr(ctx, i));
     PTR_CHAIN.head = -1;
     PTR_CHAIN.tail = -1;
 
     return ret;
 }
 
 static int
 md_process_table_block_contents(MD_CTX* ctx, int col_count, const MD_LINE* lines, int n_lines)
 {
     MD_ALIGN* align;
     int i;
     int ret = 0;
 
     /* At least two lines have to be present: The column headers and the line
      * with the underlines. */
     MD_ASSERT(n_lines >= 2);
 
     align = malloc(col_count * sizeof(MD_ALIGN));
     if(align == NULL) {
         MD_LOG("malloc() failed.");
         ret = -1;
         goto abort;
     }
 
     md_analyze_table_alignment(ctx, lines[1].beg, lines[1].end, align, col_count);
 
     MD_ENTER_BLOCK(MD_BLOCK_THEAD, NULL);
     MD_CHECK(md_process_table_row(ctx, MD_BLOCK_TH,
                         lines[0].beg, lines[0].end, align, col_count));
     MD_LEAVE_BLOCK(MD_BLOCK_THEAD, NULL);
 
     if(n_lines > 2) {
         MD_ENTER_BLOCK(MD_BLOCK_TBODY, NULL);
         for(i = 2; i < n_lines; i++) {
             MD_CHECK(md_process_table_row(ctx, MD_BLOCK_TD,
                      lines[i].beg, lines[i].end, align, col_count));
         }
         MD_LEAVE_BLOCK(MD_BLOCK_TBODY, NULL);
     }
 
 abort:
     free(align);
     return ret;
 }
 
 
 /**************************
  ***  Processing Block  ***
  **************************/
 
 #define MD_BLOCK_CONTAINER_OPENER   0x01
 #define MD_BLOCK_CONTAINER_CLOSER   0x02
 #define MD_BLOCK_CONTAINER          (MD_BLOCK_CONTAINER_OPENER | MD_BLOCK_CONTAINER_CLOSER)
 #define MD_BLOCK_LOOSE_LIST         0x04
 #define MD_BLOCK_SETEXT_HEADER      0x08
 
 struct MD_BLOCK_tag {
     MD_BLOCKTYPE type  :  8;
     unsigned flags     :  8;
 
     /* MD_BLOCK_H:      Header level (1 - 6)
      * MD_BLOCK_CODE:   Non-zero if fenced, zero if indented.
      * MD_BLOCK_LI:     Task mark character (0 if not task list item, 'x', 'X' or ' ').
      * MD_BLOCK_TABLE:  Column count (as determined by the table underline).
      */
     unsigned data      : 16;
 
     /* Leaf blocks:     Count of lines (MD_LINE or MD_VERBATIMLINE) on the block.
      * MD_BLOCK_LI:     Task mark offset in the input doc.
      * MD_BLOCK_OL:     Start item number.
      */
     unsigned n_lines;
 };
 
 struct MD_CONTAINER_tag {
     CHAR ch;
     unsigned is_loose    : 8;
     unsigned is_task     : 8;
     unsigned start;
     unsigned mark_indent;
     unsigned contents_indent;
     OFF block_byte_off;
     OFF task_mark_off;
 };
 
 
 static int
 md_process_normal_block_contents(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
 {
     int i;
     int ret;
 
     MD_CHECK(md_analyze_inlines(ctx, lines, n_lines, FALSE));
     MD_CHECK(md_process_inlines(ctx, lines, n_lines));
 
 abort:
     /* Free any temporary memory blocks stored within some dummy marks. */
     for(i = PTR_CHAIN.head; i >= 0; i = ctx->marks[i].next)
         free(md_mark_get_ptr(ctx, i));
     PTR_CHAIN.head = -1;
     PTR_CHAIN.tail = -1;
 
     return ret;
 }
 
 static int
 md_process_verbatim_block_contents(MD_CTX* ctx, MD_TEXTTYPE text_type, const MD_VERBATIMLINE* lines, int n_lines)
 {
     static const CHAR indent_chunk_str[] = _T("                ");
     static const SZ indent_chunk_size = SIZEOF_ARRAY(indent_chunk_str) - 1;
 
     int i;
     int ret = 0;
 
     for(i = 0; i < n_lines; i++) {
         const MD_VERBATIMLINE* line = &lines[i];
         int indent = line->indent;
 
         MD_ASSERT(indent >= 0);
 
         /* Output code indentation. */
         while(indent > (int) indent_chunk_size) {
             MD_TEXT(text_type, indent_chunk_str, indent_chunk_size);
             indent -= indent_chunk_size;
         }
         if(indent > 0)
             MD_TEXT(text_type, indent_chunk_str, indent);
 
         /* Output the code line itself. */
         MD_TEXT_INSECURE(text_type, STR(line->beg), line->end - line->beg);
 
         /* Enforce end-of-line. */
         MD_TEXT(text_type, _T("\n"), 1);
     }
 
 abort:
     return ret;
 }
 
 static int
 md_process_code_block_contents(MD_CTX* ctx, int is_fenced, const MD_VERBATIMLINE* lines, int n_lines)
 {
     if(is_fenced) {
         /* Skip the first line in case of fenced code: It is the fence.
          * (Only the starting fence is present due to logic in md_analyze_line().) */
         lines++;
         n_lines--;
     } else {
         /* Ignore blank lines at start/end of indented code block. */
         while(n_lines > 0  &&  lines[0].beg == lines[0].end) {
             lines++;
             n_lines--;
         }
         while(n_lines > 0  &&  lines[n_lines-1].beg == lines[n_lines-1].end) {
             n_lines--;
         }
     }
 
     if(n_lines == 0)
         return 0;
 
     return md_process_verbatim_block_contents(ctx, MD_TEXT_CODE, lines, n_lines);
 }
 
 static int
 md_setup_fenced_code_detail(MD_CTX* ctx, const MD_BLOCK* block, MD_BLOCK_CODE_DETAIL* det,
                             MD_ATTRIBUTE_BUILD* info_build, MD_ATTRIBUTE_BUILD* lang_build)
 {
     const MD_VERBATIMLINE* fence_line = (const MD_VERBATIMLINE*)(block + 1);
     OFF beg = fence_line->beg;
     OFF end = fence_line->end;
     OFF lang_end;
     CHAR fence_ch = CH(fence_line->beg);
     int ret = 0;
 
     /* Skip the fence itself. */
     while(beg < ctx->size  &&  CH(beg) == fence_ch)
         beg++;
     /* Trim initial spaces. */
     while(beg < ctx->size  &&  CH(beg) == _T(' '))
         beg++;
 
     /* Trim trailing spaces. */
     while(end > beg  &&  CH(end-1) == _T(' '))
         end--;
 
     /* Build info string attribute. */
     MD_CHECK(md_build_attribute(ctx, STR(beg), end - beg, 0, &det->info, info_build));
 
     /* Build info string attribute. */
     lang_end = beg;
     while(lang_end < end  &&  !ISWHITESPACE(lang_end))
         lang_end++;
     MD_CHECK(md_build_attribute(ctx, STR(beg), lang_end - beg, 0, &det->lang, lang_build));
 
     det->fence_char = fence_ch;
 
 abort:
     return ret;
 }
 
 static int
 md_process_leaf_block(MD_CTX* ctx, const MD_BLOCK* block)
 {
     union {
         MD_BLOCK_H_DETAIL header;
         MD_BLOCK_CODE_DETAIL code;
         MD_BLOCK_TABLE_DETAIL table;
     } det;
     MD_ATTRIBUTE_BUILD info_build;
     MD_ATTRIBUTE_BUILD lang_build;
     int is_in_tight_list;
     int clean_fence_code_detail = FALSE;
     int ret = 0;
 
     memset(&det, 0, sizeof(det));
 
     if(ctx->n_containers == 0)
         is_in_tight_list = FALSE;
     else
         is_in_tight_list = !ctx->containers[ctx->n_containers-1].is_loose;
 
     switch(block->type) {
         case MD_BLOCK_H:
             det.header.level = block->data;
             break;
 
         case MD_BLOCK_CODE:
             /* For fenced code block, we may need to set the info string. */
             if(block->data != 0) {
                 memset(&det.code, 0, sizeof(MD_BLOCK_CODE_DETAIL));
                 clean_fence_code_detail = TRUE;
                 MD_CHECK(md_setup_fenced_code_detail(ctx, block, &det.code, &info_build, &lang_build));
             }
             break;
 
         case MD_BLOCK_TABLE:
             det.table.col_count = block->data;
             det.table.head_row_count = 1;
             det.table.body_row_count = block->n_lines - 2;
             break;
 
         default:
             /* Noop. */
             break;
     }
 
     if(!is_in_tight_list  ||  block->type != MD_BLOCK_P)
         MD_ENTER_BLOCK(block->type, (void*) &det);
 
     /* Process the block contents accordingly to is type. */
     switch(block->type) {
         case MD_BLOCK_HR:
             /* noop */
             break;
 
         case MD_BLOCK_CODE:
             MD_CHECK(md_process_code_block_contents(ctx, (block->data != 0),
                             (const MD_VERBATIMLINE*)(block + 1), block->n_lines));
             break;
 
         case MD_BLOCK_HTML:
             MD_CHECK(md_process_verbatim_block_contents(ctx, MD_TEXT_HTML,
                             (const MD_VERBATIMLINE*)(block + 1), block->n_lines));
             break;
 
         case MD_BLOCK_TABLE:
             MD_CHECK(md_process_table_block_contents(ctx, block->data,
                             (const MD_LINE*)(block + 1), block->n_lines));
             break;
 
         default:
             MD_CHECK(md_process_normal_block_contents(ctx,
                             (const MD_LINE*)(block + 1), block->n_lines));
             break;
     }
 
     if(!is_in_tight_list  ||  block->type != MD_BLOCK_P)
         MD_LEAVE_BLOCK(block->type, (void*) &det);
 
 abort:
     if(clean_fence_code_detail) {
         md_free_attribute(ctx, &info_build);
         md_free_attribute(ctx, &lang_build);
     }
     return ret;
 }
 
 static int
 md_process_all_blocks(MD_CTX* ctx)
 {
     int byte_off = 0;
     int ret = 0;
 
     /* ctx->containers now is not needed for detection of lists and list items
      * so we reuse it for tracking what lists are loose or tight. We rely
      * on the fact the vector is large enough to hold the deepest nesting
      * level of lists. */
     ctx->n_containers = 0;
 
     while(byte_off < ctx->n_block_bytes) {
         MD_BLOCK* block = (MD_BLOCK*)((char*)ctx->block_bytes + byte_off);
         union {
             MD_BLOCK_UL_DETAIL ul;
             MD_BLOCK_OL_DETAIL ol;
             MD_BLOCK_LI_DETAIL li;
         } det;
 
         switch(block->type) {
             case MD_BLOCK_UL:
                 det.ul.is_tight = (block->flags & MD_BLOCK_LOOSE_LIST) ? FALSE : TRUE;
                 det.ul.mark = (CHAR) block->data;
                 break;
 
             case MD_BLOCK_OL:
                 det.ol.start = block->n_lines;
                 det.ol.is_tight =  (block->flags & MD_BLOCK_LOOSE_LIST) ? FALSE : TRUE;
                 det.ol.mark_delimiter = (CHAR) block->data;
                 break;
 
             case MD_BLOCK_LI:
                 det.li.is_task = (block->data != 0);
                 det.li.task_mark = (CHAR) block->data;
                 det.li.task_mark_offset = (OFF) block->n_lines;
                 break;
 
             default:
                 /* noop */
                 break;
         }
 
         if(block->flags & MD_BLOCK_CONTAINER) {
             if(block->flags & MD_BLOCK_CONTAINER_CLOSER) {
                 MD_LEAVE_BLOCK(block->type, &det);
 
                 if(block->type == MD_BLOCK_UL || block->type == MD_BLOCK_OL || block->type == MD_BLOCK_QUOTE)
                     ctx->n_containers--;
             }
 
             if(block->flags & MD_BLOCK_CONTAINER_OPENER) {
                 MD_ENTER_BLOCK(block->type, &det);
 
                 if(block->type == MD_BLOCK_UL || block->type == MD_BLOCK_OL) {
                     ctx->containers[ctx->n_containers].is_loose = (block->flags & MD_BLOCK_LOOSE_LIST);
                     ctx->n_containers++;
                 } else if(block->type == MD_BLOCK_QUOTE) {
                     /* This causes that any text in a block quote, even if
                      * nested inside a tight list item, is wrapped with
                      * <p>...</p>. */
                     ctx->containers[ctx->n_containers].is_loose = TRUE;
                     ctx->n_containers++;
                 }
             }
         } else {
             MD_CHECK(md_process_leaf_block(ctx, block));
 
             if(block->type == MD_BLOCK_CODE || block->type == MD_BLOCK_HTML)
                 byte_off += block->n_lines * sizeof(MD_VERBATIMLINE);
             else
                 byte_off += block->n_lines * sizeof(MD_LINE);
         }
 
         byte_off += sizeof(MD_BLOCK);
     }
 
     ctx->n_block_bytes = 0;
 
 abort:
     return ret;
 }
 
 
 /************************************
  ***  Grouping Lines into Blocks  ***
  ************************************/
 
 static void*
 md_push_block_bytes(MD_CTX* ctx, int n_bytes)
 {
     void* ptr;
 
     if(ctx->n_block_bytes + n_bytes > ctx->alloc_block_bytes) {
         void* new_block_bytes;
 
         ctx->alloc_block_bytes = (ctx->alloc_block_bytes > 0
                 ? ctx->alloc_block_bytes + ctx->alloc_block_bytes / 2
                 : 512);
         new_block_bytes = realloc(ctx->block_bytes, ctx->alloc_block_bytes);
         if(new_block_bytes == NULL) {
             MD_LOG("realloc() failed.");
             return NULL;
         }
 
         /* Fix the ->current_block after the reallocation. */
         if(ctx->current_block != NULL) {
             OFF off_current_block = (OFF) ((char*) ctx->current_block - (char*) ctx->block_bytes);
             ctx->current_block = (MD_BLOCK*) ((char*) new_block_bytes + off_current_block);
         }
 
         ctx->block_bytes = new_block_bytes;
     }
 
     ptr = (char*)ctx->block_bytes + ctx->n_block_bytes;
     ctx->n_block_bytes += n_bytes;
     return ptr;
 }
 
 static int
 md_start_new_block(MD_CTX* ctx, const MD_LINE_ANALYSIS* line)
 {
     MD_BLOCK* block;
 
     MD_ASSERT(ctx->current_block == NULL);
 
     block = (MD_BLOCK*) md_push_block_bytes(ctx, sizeof(MD_BLOCK));
     if(block == NULL)
         return -1;
 
     switch(line->type) {
         case MD_LINE_HR:
             block->type = MD_BLOCK_HR;
             break;
 
         case MD_LINE_ATXHEADER:
         case MD_LINE_SETEXTHEADER:
             block->type = MD_BLOCK_H;
             break;
 
         case MD_LINE_FENCEDCODE:
         case MD_LINE_INDENTEDCODE:
             block->type = MD_BLOCK_CODE;
             break;
 
         case MD_LINE_TEXT:
             block->type = MD_BLOCK_P;
             break;
 
         case MD_LINE_HTML:
             block->type = MD_BLOCK_HTML;
             break;
 
         case MD_LINE_BLANK:
         case MD_LINE_SETEXTUNDERLINE:
         case MD_LINE_TABLEUNDERLINE:
         default:
             MD_UNREACHABLE();
             break;
     }
 
     block->flags = 0;
     block->data = line->data;
     block->n_lines = 0;
 
     ctx->current_block = block;
     return 0;
 }
 
 /* Eat from start of current (textual) block any reference definitions and
  * remember them so we can resolve any links referring to them.
  *
  * (Reference definitions can only be at start of it as they cannot break
  * a paragraph.)
  */
 static int
 md_consume_link_reference_definitions(MD_CTX* ctx)
 {
     MD_LINE* lines = (MD_LINE*) (ctx->current_block + 1);
     int n_lines = ctx->current_block->n_lines;
     int n = 0;
 
     /* Compute how many lines at the start of the block form one or more
      * reference definitions. */
     while(n < n_lines) {
         int n_link_ref_lines;
 
         n_link_ref_lines = md_is_link_reference_definition(ctx,
                                     lines + n, n_lines - n);
         /* Not a reference definition? */
         if(n_link_ref_lines == 0)
             break;
 
         /* We fail if it is the ref. def. but it could not be stored due
          * a memory allocation error. */
         if(n_link_ref_lines < 0)
             return -1;
 
         n += n_link_ref_lines;
     }
 
     /* If there was at least one reference definition, we need to remove
      * its lines from the block, or perhaps even the whole block. */
     if(n > 0) {
         if(n == n_lines) {
             /* Remove complete block. */
             ctx->n_block_bytes -= n * sizeof(MD_LINE);
             ctx->n_block_bytes -= sizeof(MD_BLOCK);
             ctx->current_block = NULL;
         } else {
             /* Remove just some initial lines from the block. */
             memmove(lines, lines + n, (n_lines - n) * sizeof(MD_LINE));
             ctx->current_block->n_lines -= n;
             ctx->n_block_bytes -= n * sizeof(MD_LINE);
         }
     }
 
     return 0;
 }
 
 static int
 md_end_current_block(MD_CTX* ctx)
 {
     int ret = 0;
 
     if(ctx->current_block == NULL)
         return ret;
 
     /* Check whether there is a reference definition. (We do this here instead
      * of in md_analyze_line() because reference definition can take multiple
      * lines.) */
     if(ctx->current_block->type == MD_BLOCK_P  ||
        (ctx->current_block->type == MD_BLOCK_H  &&  (ctx->current_block->flags & MD_BLOCK_SETEXT_HEADER)))
     {
         MD_LINE* lines = (MD_LINE*) (ctx->current_block + 1);
         if(CH(lines[0].beg) == _T('[')) {
             MD_CHECK(md_consume_link_reference_definitions(ctx));
             if(ctx->current_block == NULL)
                 return ret;
         }
     }
 
     if(ctx->current_block->type == MD_BLOCK_H  &&  (ctx->current_block->flags & MD_BLOCK_SETEXT_HEADER)) {
         int n_lines = ctx->current_block->n_lines;
 
         if(n_lines > 1) {
             /* Get rid of the underline. */
             ctx->current_block->n_lines--;
             ctx->n_block_bytes -= sizeof(MD_LINE);
         } else {
             /* Only the underline has left after eating the ref. defs.
              * Keep the line as beginning of a new ordinary paragraph. */
             ctx->current_block->type = MD_BLOCK_P;
             return 0;
         }
     }
 
     /* Mark we are not building any block anymore. */
     ctx->current_block = NULL;
 
 abort:
     return ret;
 }
 
 static int
 md_add_line_into_current_block(MD_CTX* ctx, const MD_LINE_ANALYSIS* analysis)
 {
     MD_ASSERT(ctx->current_block != NULL);
 
     if(ctx->current_block->type == MD_BLOCK_CODE || ctx->current_block->type == MD_BLOCK_HTML) {
         MD_VERBATIMLINE* line;
 
         line = (MD_VERBATIMLINE*) md_push_block_bytes(ctx, sizeof(MD_VERBATIMLINE));
         if(line == NULL)
             return -1;
 
         line->indent = analysis->indent;
         line->beg = analysis->beg;
         line->end = analysis->end;
     } else {
         MD_LINE* line;
 
         line = (MD_LINE*) md_push_block_bytes(ctx, sizeof(MD_LINE));
         if(line == NULL)
             return -1;
 
         line->beg = analysis->beg;
         line->end = analysis->end;
     }
     ctx->current_block->n_lines++;
 
     return 0;
 }
 
 static int
 md_push_container_bytes(MD_CTX* ctx, MD_BLOCKTYPE type, unsigned start,
                         unsigned data, unsigned flags)
 {
     MD_BLOCK* block;
     int ret = 0;
 
     MD_CHECK(md_end_current_block(ctx));
 
     block = (MD_BLOCK*) md_push_block_bytes(ctx, sizeof(MD_BLOCK));
     if(block == NULL)
         return -1;
 
     block->type = type;
     block->flags = flags;
     block->data = data;
     block->n_lines = start;
 
 abort:
     return ret;
 }
 
 
 
 /***********************
  ***  Line Analysis  ***
  ***********************/
 
 static int
 md_is_hr_line(MD_CTX* ctx, OFF beg, OFF* p_end, OFF* p_killer)
 {
     OFF off = beg + 1;
     int n = 1;
 
     while(off < ctx->size  &&  (CH(off) == CH(beg) || CH(off) == _T(' ') || CH(off) == _T('\t'))) {
         if(CH(off) == CH(beg))
             n++;
         off++;
     }
 
     if(n < 3) {
         *p_killer = off;
         return FALSE;
     }
 
     /* Nothing else can be present on the line. */
     if(off < ctx->size  &&  !ISNEWLINE(off)) {
         *p_killer = off;
         return FALSE;
     }
 
     *p_end = off;
     return TRUE;
 }
 
 static int
 md_is_atxheader_line(MD_CTX* ctx, OFF beg, OFF* p_beg, OFF* p_end, unsigned* p_level)
 {
     int n;
     OFF off = beg + 1;
 
     while(off < ctx->size  &&  CH(off) == _T('#')  &&  off - beg < 7)
         off++;
     n = off - beg;
 
     if(n > 6)
         return FALSE;
     *p_level = n;
 
     if(!(ctx->parser.flags & MD_FLAG_PERMISSIVEATXHEADERS)  &&  off < ctx->size  &&
        CH(off) != _T(' ')  &&  CH(off) != _T('\t')  &&  !ISNEWLINE(off))
         return FALSE;
 
     while(off < ctx->size  &&  CH(off) == _T(' '))
         off++;
     *p_beg = off;
     *p_end = off;
     return TRUE;
 }
 
 static int
 md_is_setext_underline(MD_CTX* ctx, OFF beg, OFF* p_end, unsigned* p_level)
 {
     OFF off = beg + 1;
 
     while(off < ctx->size  &&  CH(off) == CH(beg))
         off++;
 
     /* Optionally, space(s) can follow. */
     while(off < ctx->size  &&  CH(off) == _T(' '))
         off++;
 
     /* But nothing more is allowed on the line. */
     if(off < ctx->size  &&  !ISNEWLINE(off))
         return FALSE;
 
     *p_level = (CH(beg) == _T('=') ? 1 : 2);
     *p_end = off;
     return TRUE;
 }
 
 static int
 md_is_table_underline(MD_CTX* ctx, OFF beg, OFF* p_end, unsigned* p_col_count)
 {
     OFF off = beg;
     int found_pipe = FALSE;
     unsigned col_count = 0;
 
     if(off < ctx->size  &&  CH(off) == _T('|')) {
         found_pipe = TRUE;
         off++;
         while(off < ctx->size  &&  ISWHITESPACE(off))
             off++;
     }
 
     while(1) {
         int delimited = FALSE;
 
         /* Cell underline ("-----", ":----", "----:" or ":----:") */
         if(off < ctx->size  &&  CH(off) == _T(':'))
             off++;
         if(off >= ctx->size  ||  CH(off) != _T('-'))
             return FALSE;
         while(off < ctx->size  &&  CH(off) == _T('-'))
             off++;
         if(off < ctx->size  &&  CH(off) == _T(':'))
             off++;
 
         col_count++;
 
         /* Pipe delimiter (optional at the end of line). */
         while(off < ctx->size  &&  ISWHITESPACE(off))
             off++;
         if(off < ctx->size  &&  CH(off) == _T('|')) {
             delimited = TRUE;
             found_pipe =  TRUE;
             off++;
             while(off < ctx->size  &&  ISWHITESPACE(off))
                 off++;
         }
 
         /* Success, if we reach end of line. */
         if(off >= ctx->size  ||  ISNEWLINE(off))
             break;
 
         if(!delimited)
             return FALSE;
     }
 
     if(!found_pipe)
         return FALSE;
 
     *p_end = off;
     *p_col_count = col_count;
     return TRUE;
 }
 
 static int
 md_is_opening_code_fence(MD_CTX* ctx, OFF beg, OFF* p_end)
 {
     OFF off = beg;
 
     while(off < ctx->size && CH(off) == CH(beg))
         off++;
 
     /* Fence must have at least three characters. */
     if(off - beg < 3)
         return FALSE;
 
     ctx->code_fence_length = off - beg;
 
     /* Optionally, space(s) can follow. */
     while(off < ctx->size  &&  CH(off) == _T(' '))
         off++;
 
     /* Optionally, an info string can follow. */
     while(off < ctx->size  &&  !ISNEWLINE(off)) {
         /* Backtick-based fence must not contain '`' in the info string. */
         if(CH(beg) == _T('`')  &&  CH(off) == _T('`'))
             return FALSE;
         off++;
     }
 
     *p_end = off;
     return TRUE;
 }
 
 static int
 md_is_closing_code_fence(MD_CTX* ctx, CHAR ch, OFF beg, OFF* p_end)
 {
     OFF off = beg;
     int ret = FALSE;
 
     /* Closing fence must have at least the same length and use same char as
      * opening one. */
     while(off < ctx->size  &&  CH(off) == ch)
         off++;
     if(off - beg < ctx->code_fence_length)
         goto out;
 
     /* Optionally, space(s) can follow */
     while(off < ctx->size  &&  CH(off) == _T(' '))
         off++;
 
     /* But nothing more is allowed on the line. */
     if(off < ctx->size  &&  !ISNEWLINE(off))
         goto out;
 
     ret = TRUE;
 
 out:
     /* Note we set *p_end even on failure: If we are not closing fence, caller
      * would eat the line anyway without any parsing. */
     *p_end = off;
     return ret;
 }
 
 /* Returns type of the raw HTML block, or FALSE if it is not HTML block.
  * (Refer to CommonMark specification for details about the types.)
  */
 static int
 md_is_html_block_start_condition(MD_CTX* ctx, OFF beg)
 {
     typedef struct TAG_tag TAG;
     struct TAG_tag {
         const CHAR* name;
         unsigned len    : 8;
     };
 
     /* Type 6 is started by a long list of allowed tags. We use two-level
      * tree to speed-up the search. */
 #ifdef X
     #undef X
 #endif
 #define X(name)     { _T(name), (sizeof(name)-1) / sizeof(CHAR) }
 #define Xend        { NULL, 0 }
     static const TAG t1[] = { X("pre"), X("script"), X("style"), X("textarea"), Xend };
 
     static const TAG a6[] = { X("address"), X("article"), X("aside"), Xend };
     static const TAG b6[] = { X("base"), X("basefont"), X("blockquote"), X("body"), Xend };
     static const TAG c6[] = { X("caption"), X("center"), X("col"), X("colgroup"), Xend };
     static const TAG d6[] = { X("dd"), X("details"), X("dialog"), X("dir"),
                               X("div"), X("dl"), X("dt"), Xend };
     static const TAG f6[] = { X("fieldset"), X("figcaption"), X("figure"), X("footer"),
                               X("form"), X("frame"), X("frameset"), Xend };
     static const TAG h6[] = { X("h1"), X("head"), X("header"), X("hr"), X("html"), Xend };
     static const TAG i6[] = { X("iframe"), Xend };
     static const TAG l6[] = { X("legend"), X("li"), X("link"), Xend };
     static const TAG m6[] = { X("main"), X("menu"), X("menuitem"), Xend };
     static const TAG n6[] = { X("nav"), X("noframes"), Xend };
     static const TAG o6[] = { X("ol"), X("optgroup"), X("option"), Xend };
     static const TAG p6[] = { X("p"), X("param"), Xend };
     static const TAG s6[] = { X("section"), X("source"), X("summary"), Xend };
     static const TAG t6[] = { X("table"), X("tbody"), X("td"), X("tfoot"), X("th"),
                               X("thead"), X("title"), X("tr"), X("track"), Xend };
     static const TAG u6[] = { X("ul"), Xend };
     static const TAG xx[] = { Xend };
 #undef X
 
     static const TAG* map6[26] = {
         a6, b6, c6, d6, xx, f6, xx, h6, i6, xx, xx, l6, m6,
         n6, o6, p6, xx, xx, s6, t6, u6, xx, xx, xx, xx, xx
     };
     OFF off = beg + 1;
     int i;
 
     /* Check for type 1: <script, <pre, or <style */
     for(i = 0; t1[i].name != NULL; i++) {
         if(off + t1[i].len <= ctx->size) {
             if(md_ascii_case_eq(STR(off), t1[i].name, t1[i].len))
                 return 1;
         }
     }
 
     /* Check for type 2: <!-- */
     if(off + 3 < ctx->size  &&  CH(off) == _T('!')  &&  CH(off+1) == _T('-')  &&  CH(off+2) == _T('-'))
         return 2;
 
     /* Check for type 3: <? */
     if(off < ctx->size  &&  CH(off) == _T('?'))
         return 3;
 
     /* Check for type 4 or 5: <! */
     if(off < ctx->size  &&  CH(off) == _T('!')) {
         /* Check for type 4: <! followed by uppercase letter. */
         if(off + 1 < ctx->size  &&  ISASCII(off+1))
             return 4;
 
         /* Check for type 5: <![CDATA[ */
         if(off + 8 < ctx->size) {
             if(md_ascii_eq(STR(off), _T("![CDATA["), 8))
                 return 5;
         }
     }
 
     /* Check for type 6: Many possible starting tags listed above. */
     if(off + 1 < ctx->size  &&  (ISALPHA(off) || (CH(off) == _T('/') && ISALPHA(off+1)))) {
         int slot;
         const TAG* tags;
 
         if(CH(off) == _T('/'))
             off++;
 
         slot = (ISUPPER(off) ? CH(off) - 'A' : CH(off) - 'a');
         tags = map6[slot];
 
         for(i = 0; tags[i].name != NULL; i++) {
             if(off + tags[i].len <= ctx->size) {
                 if(md_ascii_case_eq(STR(off), tags[i].name, tags[i].len)) {
                     OFF tmp = off + tags[i].len;
                     if(tmp >= ctx->size)
                         return 6;
                     if(ISBLANK(tmp) || ISNEWLINE(tmp) || CH(tmp) == _T('>'))
                         return 6;
                     if(tmp+1 < ctx->size && CH(tmp) == _T('/') && CH(tmp+1) == _T('>'))
                         return 6;
                     break;
                 }
             }
         }
     }
 
     /* Check for type 7: any COMPLETE other opening or closing tag. */
     if(off + 1 < ctx->size) {
         OFF end;
 
         if(md_is_html_tag(ctx, NULL, 0, beg, ctx->size, &end)) {
             /* Only optional whitespace and new line may follow. */
             while(end < ctx->size  &&  ISWHITESPACE(end))
                 end++;
             if(end >= ctx->size  ||  ISNEWLINE(end))
                 return 7;
         }
     }
 
     return FALSE;
 }
 
 /* Case sensitive check whether there is a substring 'what' between 'beg'
  * and end of line. */
 static int
 md_line_contains(MD_CTX* ctx, OFF beg, const CHAR* what, SZ what_len, OFF* p_end)
 {
     OFF i;
     for(i = beg; i + what_len < ctx->size; i++) {
         if(ISNEWLINE(i))
             break;
         if(memcmp(STR(i), what, what_len * sizeof(CHAR)) == 0) {
             *p_end = i + what_len;
             return TRUE;
         }
     }
 
     *p_end = i;
     return FALSE;
 }
 
 /* Returns type of HTML block end condition or FALSE if not an end condition.
  *
  * Note it fills p_end even when it is not end condition as the caller
  * does not need to analyze contents of a raw HTML block.
  */
 static int
 md_is_html_block_end_condition(MD_CTX* ctx, OFF beg, OFF* p_end)
 {
     switch(ctx->html_block_type) {
         case 1:
         {
             OFF off = beg;
 
             while(off < ctx->size  &&  !ISNEWLINE(off)) {
                 if(CH(off) == _T('<')) {
                   #define FIND_TAG_END(string, length) \
                     if(off + length <= ctx->size && \
                        md_ascii_case_eq(STR(off), _T(string), length)) { \
                         *p_end = off + length; \
                         return TRUE; \
                     }
                   FIND_TAG_END("</script>", 9)
                   FIND_TAG_END("</style>", 8)
                   FIND_TAG_END("</pre>", 6)
                   #undef FIND_TAG_END
                 }
 
                 off++;
             }
             *p_end = off;
             return FALSE;
         }
 
         case 2:
             return (md_line_contains(ctx, beg, _T("-->"), 3, p_end) ? 2 : FALSE);
 
         case 3:
             return (md_line_contains(ctx, beg, _T("?>"), 2, p_end) ? 3 : FALSE);
 
         case 4:
             return (md_line_contains(ctx, beg, _T(">"), 1, p_end) ? 4 : FALSE);
 
         case 5:
             return (md_line_contains(ctx, beg, _T("]]>"), 3, p_end) ? 5 : FALSE);
 
         case 6:     /* Pass through */
         case 7:
             *p_end = beg;
             return (beg >= ctx->size || ISNEWLINE(beg) ? ctx->html_block_type : FALSE);
 
         default:
             MD_UNREACHABLE();
     }
     return FALSE;
 }
 
 
 static int
 md_is_container_compatible(const MD_CONTAINER* pivot, const MD_CONTAINER* container)
 {
     /* Block quote has no "items" like lists. */
     if(container->ch == _T('>'))
         return FALSE;
 
     if(container->ch != pivot->ch)
         return FALSE;
     if(container->mark_indent > pivot->contents_indent)
         return FALSE;
 
     return TRUE;
 }
 
 static int
 md_push_container(MD_CTX* ctx, const MD_CONTAINER* container)
 {
     if(ctx->n_containers >= ctx->alloc_containers) {
         MD_CONTAINER* new_containers;
 
         ctx->alloc_containers = (ctx->alloc_containers > 0
                 ? ctx->alloc_containers + ctx->alloc_containers / 2
                 : 16);
         new_containers = realloc(ctx->containers, ctx->alloc_containers * sizeof(MD_CONTAINER));
         if(new_containers == NULL) {
             MD_LOG("realloc() failed.");
             return -1;
         }
 
         ctx->containers = new_containers;
     }
 
     memcpy(&ctx->containers[ctx->n_containers++], container, sizeof(MD_CONTAINER));
     return 0;
 }
 
 static int
 md_enter_child_containers(MD_CTX* ctx, int n_children)
 {
     int i;
     int ret = 0;
 
     for(i = ctx->n_containers - n_children; i < ctx->n_containers; i++) {
         MD_CONTAINER* c = &ctx->containers[i];
         int is_ordered_list = FALSE;
 
         switch(c->ch) {
             case _T(')'):
             case _T('.'):
                 is_ordered_list = TRUE;
                 MD_FALLTHROUGH();
 
             case _T('-'):
             case _T('+'):
             case _T('*'):
                 /* Remember offset in ctx->block_bytes so we can revisit the
                  * block if we detect it is a loose list. */
                 md_end_current_block(ctx);
                 c->block_byte_off = ctx->n_block_bytes;
 
                 MD_CHECK(md_push_container_bytes(ctx,
                                 (is_ordered_list ? MD_BLOCK_OL : MD_BLOCK_UL),
                                 c->start, c->ch, MD_BLOCK_CONTAINER_OPENER));
                 MD_CHECK(md_push_container_bytes(ctx, MD_BLOCK_LI,
                                 c->task_mark_off,
                                 (c->is_task ? CH(c->task_mark_off) : 0),
                                 MD_BLOCK_CONTAINER_OPENER));
                 break;
 
             case _T('>'):
                 MD_CHECK(md_push_container_bytes(ctx, MD_BLOCK_QUOTE, 0, 0, MD_BLOCK_CONTAINER_OPENER));
                 break;
 
             default:
                 MD_UNREACHABLE();
                 break;
         }
     }
 
 abort:
     return ret;
 }
 
 static int
 md_leave_child_containers(MD_CTX* ctx, int n_keep)
 {
     int ret = 0;
 
     while(ctx->n_containers > n_keep) {
         MD_CONTAINER* c = &ctx->containers[ctx->n_containers-1];
         int is_ordered_list = FALSE;
 
         switch(c->ch) {
             case _T(')'):
             case _T('.'):
                 is_ordered_list = TRUE;
                 MD_FALLTHROUGH();
 
             case _T('-'):
             case _T('+'):
             case _T('*'):
                 MD_CHECK(md_push_container_bytes(ctx, MD_BLOCK_LI,
                                 c->task_mark_off, (c->is_task ? CH(c->task_mark_off) : 0),
                                 MD_BLOCK_CONTAINER_CLOSER));
                 MD_CHECK(md_push_container_bytes(ctx,
                                 (is_ordered_list ? MD_BLOCK_OL : MD_BLOCK_UL), 0,
                                 c->ch, MD_BLOCK_CONTAINER_CLOSER));
                 break;
 
             case _T('>'):
                 MD_CHECK(md_push_container_bytes(ctx, MD_BLOCK_QUOTE, 0,
                                 0, MD_BLOCK_CONTAINER_CLOSER));
                 break;
 
             default:
                 MD_UNREACHABLE();
                 break;
         }
 
         ctx->n_containers--;
     }
 
 abort:
     return ret;
 }
 
 static int
 md_is_container_mark(MD_CTX* ctx, unsigned indent, OFF beg, OFF* p_end, MD_CONTAINER* p_container)
 {
     OFF off = beg;
     OFF max_end;
 
     if(off >= ctx->size  ||  indent >= ctx->code_indent_offset)
         return FALSE;
 
     /* Check for block quote mark. */
     if(CH(off) == _T('>')) {
         off++;
         p_container->ch = _T('>');
         p_container->is_loose = FALSE;
         p_container->is_task = FALSE;
         p_container->mark_indent = indent;
         p_container->contents_indent = indent + 1;
         *p_end = off;
         return TRUE;
     }
 
     /* Check for list item bullet mark. */
     if(ISANYOF(off, _T("-+*"))  &&  (off+1 >= ctx->size || ISBLANK(off+1) || ISNEWLINE(off+1))) {
         p_container->ch = CH(off);
         p_container->is_loose = FALSE;
         p_container->is_task = FALSE;
         p_container->mark_indent = indent;
         p_container->contents_indent = indent + 1;
         *p_end = off+1;
         return TRUE;
     }
 
     /* Check for ordered list item marks. */
     max_end = off + 9;
     if(max_end > ctx->size)
         max_end = ctx->size;
     p_container->start = 0;
     while(off < max_end  &&  ISDIGIT(off)) {
         p_container->start = p_container->start * 10 + CH(off) - _T('0');
         off++;
     }
     if(off > beg  &&
        off < ctx->size  &&
        (CH(off) == _T('.') || CH(off) == _T(')'))  &&
        (off+1 >= ctx->size || ISBLANK(off+1) || ISNEWLINE(off+1)))
     {
         p_container->ch = CH(off);
         p_container->is_loose = FALSE;
         p_container->is_task = FALSE;
         p_container->mark_indent = indent;
         p_container->contents_indent = indent + off - beg + 1;
         *p_end = off+1;
         return TRUE;
     }
 
     return FALSE;
 }
 
 static unsigned
 md_line_indentation(MD_CTX* ctx, unsigned total_indent, OFF beg, OFF* p_end)
 {
     OFF off = beg;
     unsigned indent = total_indent;
 
     while(off < ctx->size  &&  ISBLANK(off)) {
         if(CH(off) == _T('\t'))
             indent = (indent + 4) & ~3;
         else
             indent++;
         off++;
     }
 
     *p_end = off;
     return indent - total_indent;
 }
 
 static const MD_LINE_ANALYSIS md_dummy_blank_line = { MD_LINE_BLANK, 0, 0, 0, 0 };
 
 /* Analyze type of the line and find some its properties. This serves as a
  * main input for determining type and boundaries of a block. */
 static int
 md_analyze_line(MD_CTX* ctx, OFF beg, OFF* p_end,
                 const MD_LINE_ANALYSIS* pivot_line, MD_LINE_ANALYSIS* line)
 {
     unsigned total_indent = 0;
     int n_parents = 0;
     int n_brothers = 0;
     int n_children = 0;
     MD_CONTAINER container = { 0 };
     int prev_line_has_list_loosening_effect = ctx->last_line_has_list_loosening_effect;
     OFF off = beg;
     OFF hr_killer = 0;
     int ret = 0;
 
     line->indent = md_line_indentation(ctx, total_indent, off, &off);
     total_indent += line->indent;
     line->beg = off;
 
     /* Given the indentation and block quote marks '>', determine how many of
      * the current containers are our parents. */
     while(n_parents < ctx->n_containers) {
         MD_CONTAINER* c = &ctx->containers[n_parents];
 
         if(c->ch == _T('>')  &&  line->indent < ctx->code_indent_offset  &&
             off < ctx->size  &&  CH(off) == _T('>'))
         {
             /* Block quote mark. */
             off++;
             total_indent++;
             line->indent = md_line_indentation(ctx, total_indent, off, &off);
             total_indent += line->indent;
 
             /* The optional 1st space after '>' is part of the block quote mark. */
             if(line->indent > 0)
                 line->indent--;
 
             line->beg = off;
 
         } else if(c->ch != _T('>')  &&  line->indent >= c->contents_indent) {
             /* List. */
             line->indent -= c->contents_indent;
         } else {
             break;
         }
 
         n_parents++;
     }
 
     if(off >= ctx->size  ||  ISNEWLINE(off)) {
         /* Blank line does not need any real indentation to be nested inside
          * a list. */
         if(n_brothers + n_children == 0) {
             while(n_parents < ctx->n_containers  &&  ctx->containers[n_parents].ch != _T('>'))
                 n_parents++;
         }
     }
 
     while(TRUE) {
         /* Check whether we are fenced code continuation. */
         if(pivot_line->type == MD_LINE_FENCEDCODE) {
             line->beg = off;
 
             /* We are another MD_LINE_FENCEDCODE unless we are closing fence
              * which we transform into MD_LINE_BLANK. */
             if(line->indent < ctx->code_indent_offset) {
                 if(md_is_closing_code_fence(ctx, CH(pivot_line->beg), off, &off)) {
                     line->type = MD_LINE_BLANK;
                     ctx->last_line_has_list_loosening_effect = FALSE;
                     break;
                 }
             }
 
             /* Change indentation accordingly to the initial code fence. */
             if(n_parents == ctx->n_containers) {
                 if(line->indent > pivot_line->indent)
                     line->indent -= pivot_line->indent;
                 else
                     line->indent = 0;
 
                 line->type = MD_LINE_FENCEDCODE;
                 break;
             }
         }
 
         /* Check whether we are HTML block continuation. */
         if(pivot_line->type == MD_LINE_HTML  &&  ctx->html_block_type > 0) {
             if(n_parents < ctx->n_containers) {
                 /* HTML block is implicitly ended if the enclosing container
                  * block ends. */
                 ctx->html_block_type = 0;
             } else {
                 int html_block_type;
 
                 html_block_type = md_is_html_block_end_condition(ctx, off, &off);
                 if(html_block_type > 0) {
                     MD_ASSERT(html_block_type == ctx->html_block_type);
 
                     /* Make sure this is the last line of the block. */
                     ctx->html_block_type = 0;
 
                     /* Some end conditions serve as blank lines at the same time. */
                     if(html_block_type == 6 || html_block_type == 7) {
                         line->type = MD_LINE_BLANK;
                         line->indent = 0;
                         break;
                     }
                 }
 
                 line->type = MD_LINE_HTML;
                 n_parents = ctx->n_containers;
                 break;
             }
         }
 
         /* Check for blank line. */
         if(off >= ctx->size  ||  ISNEWLINE(off)) {
             if(pivot_line->type == MD_LINE_INDENTEDCODE  &&  n_parents == ctx->n_containers) {
                 line->type = MD_LINE_INDENTEDCODE;
                 if(line->indent > ctx->code_indent_offset)
                     line->indent -= ctx->code_indent_offset;
                 else
                     line->indent = 0;
                 ctx->last_line_has_list_loosening_effect = FALSE;
             } else {
                 line->type = MD_LINE_BLANK;
                 ctx->last_line_has_list_loosening_effect = (n_parents > 0  &&
                         n_brothers + n_children == 0  &&
                         ctx->containers[n_parents-1].ch != _T('>'));
 
     #if 1
                 /* See https://github.com/mity/md4c/issues/6
                  *
                  * This ugly checking tests we are in (yet empty) list item but
                  * not its very first line (i.e. not the line with the list
                  * item mark).
                  *
                  * If we are such a blank line, then any following non-blank
                  * line which would be part of the list item actually has to
                  * end the list because according to the specification, "a list
                  * item can begin with at most one blank line."
                  */
                 if(n_parents > 0  &&  ctx->containers[n_parents-1].ch != _T('>')  &&
                    n_brothers + n_children == 0  &&  ctx->current_block == NULL  &&
                    ctx->n_block_bytes > (int) sizeof(MD_BLOCK))
                 {
                     MD_BLOCK* top_block = (MD_BLOCK*) ((char*)ctx->block_bytes + ctx->n_block_bytes - sizeof(MD_BLOCK));
                     if(top_block->type == MD_BLOCK_LI)
                         ctx->last_list_item_starts_with_two_blank_lines = TRUE;
                 }
     #endif
             }
             break;
         } else {
     #if 1
             /* This is the 2nd half of the hack. If the flag is set (i.e. there
              * was a 2nd blank line at the beginning of the list item) and if
              * we would otherwise still belong to the list item, we enforce
              * the end of the list. */
             ctx->last_line_has_list_loosening_effect = FALSE;
             if(ctx->last_list_item_starts_with_two_blank_lines) {
                 if(n_parents > 0  &&  ctx->containers[n_parents-1].ch != _T('>')  &&
                    n_brothers + n_children == 0  &&  ctx->current_block == NULL  &&
                    ctx->n_block_bytes > (int) sizeof(MD_BLOCK))
                 {
                     MD_BLOCK* top_block = (MD_BLOCK*) ((char*)ctx->block_bytes + ctx->n_block_bytes - sizeof(MD_BLOCK));
                     if(top_block->type == MD_BLOCK_LI)
                         n_parents--;
                 }
 
                 ctx->last_list_item_starts_with_two_blank_lines = FALSE;
             }
     #endif
         }
 
         /* Check whether we are Setext underline. */
         if(line->indent < ctx->code_indent_offset  &&  pivot_line->type == MD_LINE_TEXT
             &&  off < ctx->size  &&  ISANYOF2(off, _T('='), _T('-'))
             &&  (n_parents == ctx->n_containers))
         {
             unsigned level;
 
             if(md_is_setext_underline(ctx, off, &off, &level)) {
                 line->type = MD_LINE_SETEXTUNDERLINE;
                 line->data = level;
                 break;
             }
         }
 
         /* Check for thematic break line. */
         if(line->indent < ctx->code_indent_offset
             &&  off < ctx->size  &&  off >= hr_killer
             &&  ISANYOF(off, _T("-_*")))
         {
             if(md_is_hr_line(ctx, off, &off, &hr_killer)) {
                 line->type = MD_LINE_HR;
                 break;
             }
         }
 
         /* Check for "brother" container. I.e. whether we are another list item
          * in already started list. */
         if(n_parents < ctx->n_containers  &&  n_brothers + n_children == 0) {
             OFF tmp;
 
             if(md_is_container_mark(ctx, line->indent, off, &tmp, &container)  &&
                md_is_container_compatible(&ctx->containers[n_parents], &container))
             {
                 pivot_line = &md_dummy_blank_line;
 
                 off = tmp;
 
                 total_indent += container.contents_indent - container.mark_indent;
                 line->indent = md_line_indentation(ctx, total_indent, off, &off);
                 total_indent += line->indent;
                 line->beg = off;
 
                 /* Some of the following whitespace actually still belongs to the mark. */
                 if(off >= ctx->size || ISNEWLINE(off)) {
                     container.contents_indent++;
                 } else if(line->indent <= ctx->code_indent_offset) {
                     container.contents_indent += line->indent;
                     line->indent = 0;
                 } else {
                     container.contents_indent += 1;
                     line->indent--;
                 }
 
                 ctx->containers[n_parents].mark_indent = container.mark_indent;
                 ctx->containers[n_parents].contents_indent = container.contents_indent;
 
                 n_brothers++;
                 continue;
             }
         }
 
         /* Check for indented code.
          * Note indented code block cannot interrupt a paragraph. */
         if(line->indent >= ctx->code_indent_offset  &&
             (pivot_line->type == MD_LINE_BLANK || pivot_line->type == MD_LINE_INDENTEDCODE))
         {
             line->type = MD_LINE_INDENTEDCODE;
             MD_ASSERT(line->indent >= ctx->code_indent_offset);
             line->indent -= ctx->code_indent_offset;
             line->data = 0;
             break;
         }
 
         /* Check for start of a new container block. */
         if(line->indent < ctx->code_indent_offset  &&
            md_is_container_mark(ctx, line->indent, off, &off, &container))
         {
             if(pivot_line->type == MD_LINE_TEXT  &&  n_parents == ctx->n_containers  &&
                         (off >= ctx->size || ISNEWLINE(off))  &&  container.ch != _T('>'))
             {
                 /* Noop. List mark followed by a blank line cannot interrupt a paragraph. */
             } else if(pivot_line->type == MD_LINE_TEXT  &&  n_parents == ctx->n_containers  &&
                         ISANYOF2_(container.ch, _T('.'), _T(')'))  &&  container.start != 1)
             {
                 /* Noop. Ordered list cannot interrupt a paragraph unless the start index is 1. */
             } else {
                 total_indent += container.contents_indent - container.mark_indent;
                 line->indent = md_line_indentation(ctx, total_indent, off, &off);
                 total_indent += line->indent;
 
                 line->beg = off;
                 line->data = container.ch;
 
                 /* Some of the following whitespace actually still belongs to the mark. */
                 if(off >= ctx->size || ISNEWLINE(off)) {
                     container.contents_indent++;
                 } else if(line->indent <= ctx->code_indent_offset) {
                     container.contents_indent += line->indent;
                     line->indent = 0;
                 } else {
                     container.contents_indent += 1;
                     line->indent--;
                 }
 
                 if(n_brothers + n_children == 0)
                     pivot_line = &md_dummy_blank_line;
 
                 if(n_children == 0)
                     MD_CHECK(md_leave_child_containers(ctx, n_parents + n_brothers));
 
                 n_children++;
                 MD_CHECK(md_push_container(ctx, &container));
                 continue;
             }
         }
 
         /* Check whether we are table continuation. */
         if(pivot_line->type == MD_LINE_TABLE  &&  n_parents == ctx->n_containers) {
             line->type = MD_LINE_TABLE;
             break;
         }
 
         /* Check for ATX header. */
         if(line->indent < ctx->code_indent_offset  &&
                 off < ctx->size  &&  CH(off) == _T('#'))
         {
             unsigned level;
 
             if(md_is_atxheader_line(ctx, off, &line->beg, &off, &level)) {
                 line->type = MD_LINE_ATXHEADER;
                 line->data = level;
                 break;
             }
         }
 
         /* Check whether we are starting code fence. */
         if(off < ctx->size  &&  ISANYOF2(off, _T('`'), _T('~'))) {
             if(md_is_opening_code_fence(ctx, off, &off)) {
                 line->type = MD_LINE_FENCEDCODE;
                 line->data = 1;
                 break;
             }
         }
 
         /* Check for start of raw HTML block. */
         if(off < ctx->size  &&  CH(off) == _T('<')
             &&  !(ctx->parser.flags & MD_FLAG_NOHTMLBLOCKS))
         {
             ctx->html_block_type = md_is_html_block_start_condition(ctx, off);
 
             /* HTML block type 7 cannot interrupt paragraph. */
             if(ctx->html_block_type == 7  &&  pivot_line->type == MD_LINE_TEXT)
                 ctx->html_block_type = 0;
 
             if(ctx->html_block_type > 0) {
                 /* The line itself also may immediately close the block. */
                 if(md_is_html_block_end_condition(ctx, off, &off) == ctx->html_block_type) {
                     /* Make sure this is the last line of the block. */
                     ctx->html_block_type = 0;
                 }
 
                 line->type = MD_LINE_HTML;
                 break;
             }
         }
 
         /* Check for table underline. */
         if((ctx->parser.flags & MD_FLAG_TABLES)  &&  pivot_line->type == MD_LINE_TEXT
             &&  off < ctx->size  &&  ISANYOF3(off, _T('|'), _T('-'), _T(':'))
             &&  n_parents == ctx->n_containers)
         {
             unsigned col_count;
 
             if(ctx->current_block != NULL  &&  ctx->current_block->n_lines == 1  &&
                 md_is_table_underline(ctx, off, &off, &col_count))
             {
                 line->data = col_count;
                 line->type = MD_LINE_TABLEUNDERLINE;
                 break;
             }
         }
 
         /* By default, we are normal text line. */
         line->type = MD_LINE_TEXT;
         if(pivot_line->type == MD_LINE_TEXT  &&  n_brothers + n_children == 0) {
             /* Lazy continuation. */
             n_parents = ctx->n_containers;
         }
 
         /* Check for task mark. */
         if((ctx->parser.flags & MD_FLAG_TASKLISTS)  &&  n_brothers + n_children > 0  &&
            ISANYOF_(ctx->containers[ctx->n_containers-1].ch, _T("-+*.)")))
         {
             OFF tmp = off;
 
             while(tmp < ctx->size  &&  tmp < off + 3  &&  ISBLANK(tmp))
                 tmp++;
             if(tmp + 2 < ctx->size  &&  CH(tmp) == _T('[')  &&
                ISANYOF(tmp+1, _T("xX "))  &&  CH(tmp+2) == _T(']')  &&
                (tmp + 3 == ctx->size  ||  ISBLANK(tmp+3)  ||  ISNEWLINE(tmp+3)))
             {
                 MD_CONTAINER* task_container = (n_children > 0 ? &ctx->containers[ctx->n_containers-1] : &container);
                 task_container->is_task = TRUE;
                 task_container->task_mark_off = tmp + 1;
                 off = tmp + 3;
                 while(off < ctx->size && ISWHITESPACE(off))
                     off++;
                 if (off == ctx->size) break;
                 line->beg = off;
             }
         }
 
         break;
     }
 
     /* Scan for end of the line.
      *
      * Note this is quite a bottleneck of the parsing as we here iterate almost
      * over compete document.
      */
 #if defined __linux__ && !defined MD4C_USE_UTF16
     /* Recent glibc versions have superbly optimized strcspn(), even using
      * vectorization if available. */
     if(ctx->doc_ends_with_newline  &&  off < ctx->size) {
         while(TRUE) {
             off += (OFF) strcspn(STR(off), "\r\n");
 
             /* strcspn() can stop on zero terminator; but that can appear
              * anywhere in the Markfown input... */
             if(CH(off) == _T('\0'))
                 off++;
             else
                 break;
         }
     } else
 #endif
     {
         /* Optimization: Use some loop unrolling. */
         while(off + 3 < ctx->size  &&  !ISNEWLINE(off+0)  &&  !ISNEWLINE(off+1)
                                    &&  !ISNEWLINE(off+2)  &&  !ISNEWLINE(off+3))
             off += 4;
         while(off < ctx->size  &&  !ISNEWLINE(off))
             off++;
     }
 
     /* Set end of the line. */
     line->end = off;
 
     /* But for ATX header, we should exclude the optional trailing mark. */
     if(line->type == MD_LINE_ATXHEADER) {
         OFF tmp = line->end;
         while(tmp > line->beg && CH(tmp-1) == _T(' '))
             tmp--;
         while(tmp > line->beg && CH(tmp-1) == _T('#'))
             tmp--;
         if(tmp == line->beg || CH(tmp-1) == _T(' ') || (ctx->parser.flags & MD_FLAG_PERMISSIVEATXHEADERS))
             line->end = tmp;
     }
 
     /* Trim trailing spaces. */
     if(line->type != MD_LINE_INDENTEDCODE  &&  line->type != MD_LINE_FENCEDCODE) {
         while(line->end > line->beg && CH(line->end-1) == _T(' '))
             line->end--;
     }
 
     /* Eat also the new line. */
     if(off < ctx->size && CH(off) == _T('\r'))
         off++;
     if(off < ctx->size && CH(off) == _T('\n'))
         off++;
 
     *p_end = off;
 
     /* If we belong to a list after seeing a blank line, the list is loose. */
     if(prev_line_has_list_loosening_effect  &&  line->type != MD_LINE_BLANK  &&  n_parents + n_brothers > 0) {
         MD_CONTAINER* c = &ctx->containers[n_parents + n_brothers - 1];
         if(c->ch != _T('>')) {
             MD_BLOCK* block = (MD_BLOCK*) (((char*)ctx->block_bytes) + c->block_byte_off);
             block->flags |= MD_BLOCK_LOOSE_LIST;
         }
     }
 
     /* Leave any containers we are not part of anymore. */
     if(n_children == 0  &&  n_parents + n_brothers < ctx->n_containers)
         MD_CHECK(md_leave_child_containers(ctx, n_parents + n_brothers));
 
     /* Enter any container we found a mark for. */
     if(n_brothers > 0) {
         MD_ASSERT(n_brothers == 1);
         MD_CHECK(md_push_container_bytes(ctx, MD_BLOCK_LI,
                     ctx->containers[n_parents].task_mark_off,
                     (ctx->containers[n_parents].is_task ? CH(ctx->containers[n_parents].task_mark_off) : 0),
                     MD_BLOCK_CONTAINER_CLOSER));
         MD_CHECK(md_push_container_bytes(ctx, MD_BLOCK_LI,
                     container.task_mark_off,
                     (container.is_task ? CH(container.task_mark_off) : 0),
                     MD_BLOCK_CONTAINER_OPENER));
         ctx->containers[n_parents].is_task = container.is_task;
         ctx->containers[n_parents].task_mark_off = container.task_mark_off;
     }
 
     if(n_children > 0)
         MD_CHECK(md_enter_child_containers(ctx, n_children));
 
 abort:
     return ret;
 }
 
 static int
 md_process_line(MD_CTX* ctx, const MD_LINE_ANALYSIS** p_pivot_line, MD_LINE_ANALYSIS* line)
 {
     const MD_LINE_ANALYSIS* pivot_line = *p_pivot_line;
     int ret = 0;
 
     /* Blank line ends current leaf block. */
     if(line->type == MD_LINE_BLANK) {
         MD_CHECK(md_end_current_block(ctx));
         *p_pivot_line = &md_dummy_blank_line;
         return 0;
     }
 
     /* Some line types form block on their own. */
     if(line->type == MD_LINE_HR || line->type == MD_LINE_ATXHEADER) {
         MD_CHECK(md_end_current_block(ctx));
 
         /* Add our single-line block. */
         MD_CHECK(md_start_new_block(ctx, line));
         MD_CHECK(md_add_line_into_current_block(ctx, line));
         MD_CHECK(md_end_current_block(ctx));
         *p_pivot_line = &md_dummy_blank_line;
         return 0;
     }
 
     /* MD_LINE_SETEXTUNDERLINE changes meaning of the current block and ends it. */
     if(line->type == MD_LINE_SETEXTUNDERLINE) {
         MD_ASSERT(ctx->current_block != NULL);
         ctx->current_block->type = MD_BLOCK_H;
         ctx->current_block->data = line->data;
         ctx->current_block->flags |= MD_BLOCK_SETEXT_HEADER;
         MD_CHECK(md_add_line_into_current_block(ctx, line));
         MD_CHECK(md_end_current_block(ctx));
         if(ctx->current_block == NULL) {
             *p_pivot_line = &md_dummy_blank_line;
         } else {
             /* This happens if we have consumed all the body as link ref. defs.
              * and downgraded the underline into start of a new paragraph block. */
             line->type = MD_LINE_TEXT;
             *p_pivot_line = line;
         }
         return 0;
     }
 
     /* MD_LINE_TABLEUNDERLINE changes meaning of the current block. */
     if(line->type == MD_LINE_TABLEUNDERLINE) {
         MD_ASSERT(ctx->current_block != NULL);
         MD_ASSERT(ctx->current_block->n_lines == 1);
         ctx->current_block->type = MD_BLOCK_TABLE;
         ctx->current_block->data = line->data;
         MD_ASSERT(pivot_line != &md_dummy_blank_line);
         ((MD_LINE_ANALYSIS*)pivot_line)->type = MD_LINE_TABLE;
         MD_CHECK(md_add_line_into_current_block(ctx, line));
         return 0;
     }
 
     /* The current block also ends if the line has different type. */
     if(line->type != pivot_line->type)
         MD_CHECK(md_end_current_block(ctx));
 
     /* The current line may start a new block. */
     if(ctx->current_block == NULL) {
         MD_CHECK(md_start_new_block(ctx, line));
         *p_pivot_line = line;
     }
 
     /* In all other cases the line is just a continuation of the current block. */
     MD_CHECK(md_add_line_into_current_block(ctx, line));
 
 abort:
     return ret;
 }
 
 static int
 md_process_doc(MD_CTX *ctx)
 {
     const MD_LINE_ANALYSIS* pivot_line = &md_dummy_blank_line;
     MD_LINE_ANALYSIS line_buf[2];
     MD_LINE_ANALYSIS* line = &line_buf[0];
     OFF off = 0;
     int ret = 0;
 
     MD_ENTER_BLOCK(MD_BLOCK_DOC, NULL);
 
     while(off < ctx->size) {
         if(line == pivot_line)
             line = (line == &line_buf[0] ? &line_buf[1] : &line_buf[0]);
 
         MD_CHECK(md_analyze_line(ctx, off, &off, pivot_line, line));
         MD_CHECK(md_process_line(ctx, &pivot_line, line));
     }
 
     md_end_current_block(ctx);
 
     MD_CHECK(md_build_ref_def_hashtable(ctx));
 
     /* Process all blocks. */
     MD_CHECK(md_leave_child_containers(ctx, 0));
     MD_CHECK(md_process_all_blocks(ctx));
 
     MD_LEAVE_BLOCK(MD_BLOCK_DOC, NULL);
 
 abort:
 
 #if 0
     /* Output some memory consumption statistics. */
     {
         char buffer[256];
         sprintf(buffer, "Alloced %u bytes for block buffer.",
                     (unsigned)(ctx->alloc_block_bytes));
         MD_LOG(buffer);
 
         sprintf(buffer, "Alloced %u bytes for containers buffer.",
                     (unsigned)(ctx->alloc_containers * sizeof(MD_CONTAINER)));
         MD_LOG(buffer);
 
         sprintf(buffer, "Alloced %u bytes for marks buffer.",
                     (unsigned)(ctx->alloc_marks * sizeof(MD_MARK)));
         MD_LOG(buffer);
 
         sprintf(buffer, "Alloced %u bytes for aux. buffer.",
                     (unsigned)(ctx->alloc_buffer * sizeof(MD_CHAR)));
         MD_LOG(buffer);
     }
 #endif
 
     return ret;
 }
 
 
 /********************
  ***  Public API  ***
  ********************/
 
 int
 md_parse(const MD_CHAR* text, MD_SIZE size, const MD_PARSER* parser, void* userdata)
 {
     MD_CTX ctx = {.text = text,
                   .size = size,
                   .userdata = userdata,
                   .code_indent_offset = (ctx.parser.flags & MD_FLAG_NOINDENTEDCODEBLOCKS) ? (OFF)(-1) : 4,
                   .doc_ends_with_newline = (size > 0  &&  ISNEWLINE_(text[size-1]))};
     int i;
     int ret;
 
     if(parser->abi_version != 0) {
         if(parser->debug_log != NULL)
             parser->debug_log("Unsupported abi_version.", userdata);
         return -1;
     }
 
     /* Setup context structure. */
     memcpy(&ctx.parser, parser, sizeof(MD_PARSER));
     md_build_mark_char_map(&ctx);
 
     /* Reset all unresolved opener mark chains. */
     for(i = 0; i < (int) SIZEOF_ARRAY(ctx.mark_chains); i++) {
         ctx.mark_chains[i].head = -1;
         ctx.mark_chains[i].tail = -1;
     }
     ctx.unresolved_link_head = -1;
     ctx.unresolved_link_tail = -1;
 
     /* All the work. */
     ret = md_process_doc(&ctx);
 
     /* Clean-up. */
     md_free_ref_defs(&ctx);
     md_free_ref_def_hashtable(&ctx);
     free(ctx.buffer);
     free(ctx.marks);
     free(ctx.block_bytes);
     free(ctx.containers);
 
     return ret;
 }