Upgrade md4c to 0.4.7

Change-Id: I9400c2df13c30fb0bc14728a0c44851c2d1e9079
Pick-to: 6.0 5.15
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

4 files changed, 131 insertions, 86 deletions

diff --git a/src/3rdparty/md4c/LICENSE.md b/src/3rdparty/md4c/LICENSE.md
index d58ef9341d..2088ba453e 100644
--- a/src/3rdparty/md4c/LICENSE.md
+++ b/src/3rdparty/md4c/LICENSE.md
@@ -1,7 +1,7 @@
 
 # The MIT License (MIT)
 
-Copyright © 2016-2019 Martin Mitáš
+Copyright © 2016-2020 Martin Mitáš
 
 Permission is hereby granted, free of charge, to any person obtaining a
 copy of this software and associated documentation files (the “Software”),
diff --git a/src/3rdparty/md4c/md4c.c b/src/3rdparty/md4c/md4c.c
index 0119e7a55a..19ba212a09 100644
--- a/src/3rdparty/md4c/md4c.c
+++ b/src/3rdparty/md4c/md4c.c
@@ -72,6 +72,48 @@
     #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  ***
@@ -230,41 +272,6 @@ struct MD_VERBATIMLINE_tag {
 };
 
 
-/*******************
- ***  Debugging  ***
- *******************/
-
-#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
-
-
 /*****************
  ***  Helpers  ***
  *****************/
@@ -466,7 +473,7 @@ md_text_with_null_replacement(MD_CTX* ctx, MD_TEXTTYPE type, const CHAR* str, SZ
 typedef struct MD_UNICODE_FOLD_INFO_tag MD_UNICODE_FOLD_INFO;
 struct MD_UNICODE_FOLD_INFO_tag {
     unsigned codepoints[3];
-    int n_codepoints;
+    unsigned n_codepoints;
 };
 
 
@@ -670,7 +677,7 @@ struct MD_UNICODE_FOLD_INFO_tag {
             const unsigned* map;
             const unsigned* data;
             size_t map_size;
-            int n_codepoints;
+            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 },
@@ -695,7 +702,7 @@ struct MD_UNICODE_FOLD_INFO_tag {
             index = md_unicode_bsearch__(codepoint, FOLD_MAP_LIST[i].map, FOLD_MAP_LIST[i].map_size);
             if(index >= 0) {
                 /* Found the mapping. */
-                int n_codepoints = FOLD_MAP_LIST[i].n_codepoints;
+                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);
 
@@ -894,6 +901,8 @@ md_merge_lines(MD_CTX* ctx, OFF beg, OFF end, const MD_LINE* lines, int n_lines,
     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;
@@ -1235,6 +1244,7 @@ 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++;
@@ -1251,6 +1261,7 @@ 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++;
@@ -1267,6 +1278,7 @@ 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++;
@@ -1372,6 +1384,8 @@ md_build_attr_append_substr(MD_CTX* ctx, MD_ATTRIBUTE_BUILD* build,
 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);
@@ -1547,12 +1561,6 @@ md_link_label_cmp_load_fold_info(const CHAR* label, OFF off, SZ size,
         goto whitespace;
     }
 
-    if(ISNEWLINE_(label[off])) {
-        /* Treat new lines as a whitespace. */
-        off++;
-        goto whitespace;
-    }
-
     codepoint = md_decode_unicode(label, off, size, &char_size);
     off += char_size;
     if(ISUNICODEWHITESPACE_(codepoint)) {
@@ -1575,8 +1583,6 @@ md_link_label_cmp(const CHAR* a_label, SZ a_size, const CHAR* b_label, SZ b_size
 {
     OFF a_off;
     OFF b_off;
-    int a_reached_end = FALSE;
-    int b_reached_end = FALSE;
     MD_UNICODE_FOLD_INFO a_fi = { { 0 }, 0 };
     MD_UNICODE_FOLD_INFO b_fi = { { 0 }, 0 };
     OFF a_fi_off = 0;
@@ -1585,17 +1591,17 @@ md_link_label_cmp(const CHAR* a_label, SZ a_size, const CHAR* b_label, SZ b_size
 
     a_off = md_skip_unicode_whitespace(a_label, 0, a_size);
     b_off = md_skip_unicode_whitespace(b_label, 0, b_size);
-    while(!a_reached_end  ||  !b_reached_end) {
+    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);
-            a_reached_end = (a_off >= a_size);
         }
         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);
-            b_reached_end = (b_off >= b_size);
         }
 
         cmp = b_fi.codepoints[b_fi_off] - a_fi.codepoints[a_fi_off];
@@ -2671,7 +2677,7 @@ md_rollback(MD_CTX* ctx, int opener_index, int closer_index, int how)
                     mark_index = mark->prev;
                     break;
                 }
-                /* Pass through. */
+                MD_FALLTHROUGH();
             default:
                 mark_index--;
                 break;
@@ -3227,7 +3233,7 @@ md_collect_marks(MD_CTX* ctx, const MD_LINE* lines, int n_lines, int table_mode)
                         /* Push a dummy as a reserve for a closer. */
                         PUSH_MARK('D', off, off, 0);
                         off += 1 + suffix_size;
-                        continue;
+                        break;
                     }
                 }
 
@@ -3524,6 +3530,10 @@ md_resolve_links(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
             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('(')) {
@@ -3679,7 +3689,7 @@ md_analyze_emph(MD_CTX* ctx, int 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;
+        int opener_index = 0;
 
         if(mark->ch == _T('*')) {
             MD_MARKCHAIN* opener_chains[6];
@@ -3806,6 +3816,7 @@ md_analyze_permissive_url_autolink(MD_CTX* ctx, int mark_index)
     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) {
@@ -3844,17 +3855,28 @@ md_analyze_permissive_url_autolink(MD_CTX* ctx, int mark_index)
             if(n_opened_parenthesis > 0)
                 n_opened_parenthesis--;
             else
-                break;
+                n_excess_parenthesis++;
         }
 
         off++;
     }
-    /* These cannot be last char In such case they are more likely normal
-     * punctuation. */
-    if(ISANYOF(off-1, _T("?!.,:*_~")))
-        off--;
 
-    /* Ok. Lets call it auto-link. Adapt opener and create closer to zero
+    /* 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');
     opener->end = opener->beg;
@@ -3918,6 +3940,8 @@ 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];
@@ -4136,7 +4160,7 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
                         }
                         break;
                     }
-                    /* Fall though. */
+                    MD_FALLTHROUGH();
 
                 case '*':       /* Emphasis, strong emphasis. */
                     if(mark->flags & MD_MARK_OPENER) {
@@ -4235,6 +4259,7 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
                         break;
                     }
                     /* Pass through, if auto-link. */
+                    MD_FALLTHROUGH();
 
                 case '@':       /* Permissive e-mail autolink. */
                 case ':':       /* Permissive URL autolink. */
@@ -4491,12 +4516,14 @@ md_process_table_block_contents(MD_CTX* ctx, int col_count, const MD_LINE* lines
                         lines[0].beg, lines[0].end, align, col_count));
     MD_LEAVE_BLOCK(MD_BLOCK_THEAD, NULL);
 
-    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));
+    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);
     }
-    MD_LEAVE_BLOCK(MD_BLOCK_TBODY, NULL);
 
 abort:
     free(align);
@@ -4665,6 +4692,7 @@ 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;
@@ -4693,6 +4721,12 @@ md_process_leaf_block(MD_CTX* ctx, const MD_BLOCK* block)
             }
             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;
@@ -5504,7 +5538,7 @@ md_enter_child_containers(MD_CTX* ctx, int n_children, unsigned data)
             case _T(')'):
             case _T('.'):
                 is_ordered_list = TRUE;
-                /* Pass through */
+                MD_FALLTHROUGH();
 
             case _T('-'):
             case _T('+'):
@@ -5550,7 +5584,7 @@ md_leave_child_containers(MD_CTX* ctx, int n_keep)
             case _T(')'):
             case _T('.'):
                 is_ordered_list = TRUE;
-                /* Pass through */
+                MD_FALLTHROUGH();
 
             case _T('-'):
             case _T('+'):
@@ -5586,11 +5620,11 @@ md_is_container_mark(MD_CTX* ctx, unsigned indent, OFF beg, OFF* p_end, MD_CONTA
     OFF off = beg;
     OFF max_end;
 
-    if(indent >= ctx->code_indent_offset)
+    if(off >= ctx->size  ||  indent >= ctx->code_indent_offset)
         return FALSE;
 
     /* Check for block quote mark. */
-    if(off < ctx->size  &&  CH(off) == _T('>')) {
+    if(CH(off) == _T('>')) {
         off++;
         p_container->ch = _T('>');
         p_container->is_loose = FALSE;
@@ -5602,13 +5636,13 @@ md_is_container_mark(MD_CTX* ctx, unsigned indent, OFF beg, OFF* p_end, MD_CONTA
     }
 
     /* Check for list item bullet mark. */
-    if(off+1 < ctx->size  &&  ISANYOF(off, _T("-+*"))  &&  (ISBLANK(off+1) || ISNEWLINE(off+1))) {
+    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;
+        *p_end = off+1;
         return TRUE;
     }
 
@@ -5621,16 +5655,16 @@ md_is_container_mark(MD_CTX* ctx, unsigned indent, OFF beg, OFF* p_end, MD_CONTA
         p_container->start = p_container->start * 10 + CH(off) - _T('0');
         off++;
     }
-    if(off > beg  &&  off+1 < ctx->size  &&
+    if(off > beg  &&
        (CH(off) == _T('.') || CH(off) == _T(')'))  &&
-       (ISBLANK(off+1) || ISNEWLINE(off+1)))
+       (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;
+        *p_end = off+1;
         return TRUE;
     }
 
@@ -5655,7 +5689,7 @@ md_line_indentation(MD_CTX* ctx, unsigned total_indent, OFF beg, OFF* p_end)
     return indent - total_indent;
 }
 
-static const MD_LINE_ANALYSIS md_dummy_blank_line = { MD_LINE_BLANK, 0 };
+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. */
@@ -5786,12 +5820,14 @@ md_analyze_line(MD_CTX* ctx, OFF beg, OFF* p_end,
     #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 (with the list item mark).
+                 * 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 blank line, then any following non-blank line
-                 * which would be part of this list item actually ends the list
-                 * because "a list item can begin with at most one blank line."
+                 * 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  &&
@@ -5806,9 +5842,10 @@ md_analyze_line(MD_CTX* ctx, OFF beg, OFF* p_end,
             break;
         } else {
     #if 1
-            /* This is 2nd half of the hack. If the flag is set (that is there
-             * were 2nd blank line at the start of the list item) and we would also
-             * belonging to such list item, than interrupt the list. */
+            /* 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('>')  &&
diff --git a/src/3rdparty/md4c/md4c.h b/src/3rdparty/md4c/md4c.h
index 8bba71242d..95f78f9b9b 100644
--- a/src/3rdparty/md4c/md4c.h
+++ b/src/3rdparty/md4c/md4c.h
@@ -91,7 +91,8 @@ typedef enum MD_BLOCKTYPE {
     MD_BLOCK_P,
 
     /* <table>...</table> and its contents.
-     * Detail: Structure MD_BLOCK_TD_DETAIL (used with MD_BLOCK_TH and MD_BLOCK_TD)
+     * Detail: Structure MD_BLOCK_TABLE_DETAIL (for MD_BLOCK_TABLE),
+     *         structure MD_BLOCK_TD_DETAIL (for MD_BLOCK_TH and MD_BLOCK_TD)
      * Note all of these are used only if extension MD_FLAG_TABLES is enabled. */
     MD_BLOCK_TABLE,
     MD_BLOCK_THEAD,
@@ -267,6 +268,13 @@ typedef struct MD_BLOCK_CODE_DETAIL {
     MD_CHAR fence_char;     /* The character used for fenced code block; or zero for indented code block. */
 } MD_BLOCK_CODE_DETAIL;
 
+/* Detailed info for MD_BLOCK_TABLE. */
+typedef struct MD_BLOCK_TABLE_DETAIL {
+    unsigned col_count;         /* Count of columns in the table. */
+    unsigned head_row_count;    /* Count of rows in the table header (currently always 1) */
+    unsigned body_row_count;    /* Count of rows in the table body */
+} MD_BLOCK_TABLE_DETAIL;
+
 /* Detailed info for MD_BLOCK_TH and MD_BLOCK_TD. */
 typedef struct MD_BLOCK_TD_DETAIL {
     MD_ALIGN align;
diff --git a/src/3rdparty/md4c/qt_attribution.json b/src/3rdparty/md4c/qt_attribution.json
index 024cf5ed80..8f2296e2d2 100644
--- a/src/3rdparty/md4c/qt_attribution.json
+++ b/src/3rdparty/md4c/qt_attribution.json
@@ -9,7 +9,7 @@
     "License": "MIT License",
     "LicenseId": "MIT",
     "LicenseFile": "LICENSE.md",
-    "Version": "0.4.6",
-    "DownloadLocation": "https://github.com/mity/md4c/releases/tag/release-0.4.6",
+    "Version": "0.4.7",
+    "DownloadLocation": "https://github.com/mity/md4c/releases/tag/release-0.4.7",
     "Copyright": "Copyright © 2016-2020 Martin Mitáš"
 }