Update common mark code from upstream

lib/commonmarker/src/arena.c

@@ -68,15 +68,16 @@ static void *arena_calloc(size_t nmem, size_t size) {
   const size_t align = sizeof(size_t) - 1;
   sz = (sz + align) & ~align;
 
+  struct arena_chunk *chunk;
   if (sz > A->sz) {
-    A->prev = alloc_arena_chunk(sz, A->prev);
-    return (uint8_t *) A->prev->ptr + sizeof(size_t);
+    A->prev = chunk = alloc_arena_chunk(sz, A->prev);
+  } else if (sz > A->sz - A->used) {
+    A = chunk = alloc_arena_chunk(A->sz + A->sz / 2, A);
+  } else {
+    chunk = A;
   }
-  if (sz > A->sz - A->used) {
-    A = alloc_arena_chunk(A->sz + A->sz / 2, A);
-  }
-  void *ptr = (uint8_t *) A->ptr + A->used;
-  A->used += sz;
+  void *ptr = (uint8_t *) chunk->ptr + chunk->used;
+  chunk->used += sz;
   *((size_t *) ptr) = sz - sizeof(size_t);
   return (uint8_t *) ptr + sizeof(size_t);
 }
@@ -98,6 +99,6 @@ static void arena_free(void *ptr) {
 
 cmark_mem CMARK_ARENA_MEM_ALLOCATOR = {arena_calloc, arena_realloc, arena_free};
 
-cmark_mem *cmark_get_arena_mem_allocator() {
+cmark_mem *cmark_get_arena_mem_allocator(void) {
   return &CMARK_ARENA_MEM_ALLOCATOR;
 }

lib/commonmarker/src/blocks.c

@@ -8,6 +8,7 @@
 #include <stdlib.h>
 #include <assert.h>
 #include <stdio.h>
+#include <limits.h>
 
 #include "cmark_ctype.h"
 #include "syntax_extension.h"
@@ -26,6 +27,14 @@
 #define CODE_INDENT 4
 #define TAB_STOP 4
 
+/**
+ * Very deeply nested lists can cause quadratic performance issues.
+ * This constant is used in open_new_blocks() to limit the nesting
+ * depth. It is unlikely that a non-contrived markdown document will
+ * be nested this deeply.
+ */
+#define MAX_LIST_DEPTH 100
+
 #ifndef MIN
 #define MIN(x, y) ((x < y) ? x : y)
 #endif
@@ -639,6 +648,14 @@ static cmark_node *finalize_document(cmark_parser *parser) {
   }
 
   finalize(parser, parser->root);
+
+  // Limit total size of extra content created from reference links to
+  // document size to avoid superlinear growth. Always allow 100KB.
+  if (parser->total_size > 100000)
+    parser->refmap->max_ref_size = parser->total_size;
+  else
+    parser->refmap->max_ref_size = 100000;
+
   process_inlines(parser, parser->refmap, parser->options);
   if (parser->options & CMARK_OPT_FOOTNOTES)
     process_footnotes(parser);
@@ -698,6 +715,11 @@ static void S_parser_feed(cmark_parser *parser, const unsigned char *buffer,
   const unsigned char *end = buffer + len;
   static const uint8_t repl[] = {239, 191, 189};
 
+  if (len > UINT_MAX - parser->total_size)
+    parser->total_size = UINT_MAX;
+  else
+    parser->total_size += len;
+
   if (parser->last_buffer_ended_with_cr && *buffer == '\n') {
     // skip NL if last buffer ended with CR ; see #117
     buffer++;
@@ -1105,10 +1127,11 @@ static void open_new_blocks(cmark_parser *parser, cmark_node **container,
   bool has_content;
   int save_offset;
   int save_column;
+  size_t depth = 0;
 
   while (cont_type != CMARK_NODE_CODE_BLOCK &&
          cont_type != CMARK_NODE_HTML_BLOCK) {
-
+    depth++;
     S_find_first_nonspace(parser, input);
     indented = parser->indent >= CODE_INDENT;
 
@@ -1194,22 +1217,25 @@ static void open_new_blocks(cmark_parser *parser, cmark_node **container,
                              parser->first_nonspace + 1);
       S_advance_offset(parser, input, input->len - 1 - parser->offset, false);
     } else if (!indented &&
-               parser->options & CMARK_OPT_FOOTNOTES &&
+               (parser->options & CMARK_OPT_FOOTNOTES) &&
+               depth < MAX_LIST_DEPTH &&
                (matched = scan_footnote_definition(input, parser->first_nonspace))) {
       cmark_chunk c = cmark_chunk_dup(input, parser->first_nonspace + 2, matched - 2);
-      cmark_chunk_to_cstr(parser->mem, &c);
 
       while (c.data[c.len - 1] != ']')
         --c.len;
       --c.len;
 
+      cmark_chunk_to_cstr(parser->mem, &c);
+
       S_advance_offset(parser, input, parser->first_nonspace + matched - parser->offset, false);
       *container = add_child(parser, *container, CMARK_NODE_FOOTNOTE_DEFINITION, parser->first_nonspace + matched + 1);
       (*container)->as.literal = c;
 
       (*container)->internal_offset = matched;
     } else if ((!indented || cont_type == CMARK_NODE_LIST) &&
 	       parser->indent < 4 &&
+               depth < MAX_LIST_DEPTH &&
                (matched = parse_list_marker(
                     parser->mem, input, parser->first_nonspace,
                     (*container)->type == CMARK_NODE_PARAGRAPH, &data))) {

lib/commonmarker/src/cmark-gfm-extension_api.h

@@ -114,6 +114,7 @@ typedef struct delimiter {
   struct delimiter *previous;
   struct delimiter *next;
   cmark_node *inl_text;
+  bufsize_t position;
   bufsize_t length;
   unsigned char delim_char;
   int can_open;

lib/commonmarker/src/cmark-gfm.h

@@ -111,13 +111,13 @@ typedef struct cmark_mem {
  * realloc and free.
  */
 CMARK_GFM_EXPORT
-cmark_mem *cmark_get_default_mem_allocator();
+cmark_mem *cmark_get_default_mem_allocator(void);
 
 /** An arena allocator; uses system calloc to allocate large
  * slabs of memory.  Memory in these slabs is not reused at all.
  */
 CMARK_GFM_EXPORT
-cmark_mem *cmark_get_arena_mem_allocator();
+cmark_mem *cmark_get_arena_mem_allocator(void);
 
 /** Resets the arena allocator, quickly returning all used memory
  * to the operating system.
@@ -225,6 +225,11 @@ CMARK_GFM_EXPORT cmark_node *cmark_node_first_child(cmark_node *node);
  */
 CMARK_GFM_EXPORT cmark_node *cmark_node_last_child(cmark_node *node);
 
+/** Returns the footnote reference of 'node', or NULL if 'node' doesn't have a
+ * footnote reference.
+ */
+CMARK_GFM_EXPORT cmark_node *cmark_node_parent_footnote_def(cmark_node *node);
+
 /**
  * ## Iterator
  *
@@ -408,6 +413,17 @@ CMARK_GFM_EXPORT int cmark_node_get_list_tight(cmark_node *node);
  */
 CMARK_GFM_EXPORT int cmark_node_set_list_tight(cmark_node *node, int tight);
 
+/**
+ * Returns item index of 'node'. This is only used when rendering output
+ * formats such as commonmark, which need to output the index. It is not
+ * required for formats such as html or latex.
+ */
+CMARK_GFM_EXPORT int cmark_node_get_item_index(cmark_node *node);
+
+/** Sets item index of 'node'. Returns 1 on success, 0 on failure.
+ */
+CMARK_GFM_EXPORT int cmark_node_set_item_index(cmark_node *node, int idx);
+
 /** Returns the info string from a fenced code block.
  */
 CMARK_GFM_EXPORT const char *cmark_node_get_fence_info(cmark_node *node);

lib/commonmarker/src/cmark.c

@@ -10,9 +10,9 @@
 cmark_node_type CMARK_NODE_LAST_BLOCK = CMARK_NODE_FOOTNOTE_DEFINITION;
 cmark_node_type CMARK_NODE_LAST_INLINE = CMARK_NODE_FOOTNOTE_REFERENCE;
 
-int cmark_version() { return CMARK_GFM_VERSION; }
+int cmark_version(void) { return CMARK_GFM_VERSION; }
 
-const char *cmark_version_string() { return CMARK_GFM_VERSION_STRING; }
+const char *cmark_version_string(void) { return CMARK_GFM_VERSION_STRING; }
 
 static void *xcalloc(size_t nmem, size_t size) {
   void *ptr = calloc(nmem, size);
@@ -38,7 +38,7 @@ static void xfree(void *ptr) {
 
 cmark_mem CMARK_DEFAULT_MEM_ALLOCATOR = {xcalloc, xrealloc, xfree};
 
-cmark_mem *cmark_get_default_mem_allocator() {
+cmark_mem *cmark_get_default_mem_allocator(void) {
   return &CMARK_DEFAULT_MEM_ALLOCATOR;
 }
 

lib/commonmarker/src/commonmark.c

@@ -153,23 +153,8 @@ static bool is_autolink(cmark_node *node) {
                   link_text->as.literal.len) == 0);
 }
 
-// if node is a block node, returns node.
-// otherwise returns first block-level node that is an ancestor of node.
-// if there is no block-level ancestor, returns NULL.
-static cmark_node *get_containing_block(cmark_node *node) {
-  while (node) {
-    if (CMARK_NODE_BLOCK_P(node)) {
-      return node;
-    } else {
-      node = node->parent;
-    }
-  }
-  return NULL;
-}
-
 static int S_render_node(cmark_renderer *renderer, cmark_node *node,
                          cmark_event_type ev_type, int options) {
-  cmark_node *tmp;
   int list_number;
   cmark_delim_type list_delim;
   int numticks;
@@ -180,7 +165,7 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
   char fencechar[2] = {'\0', '\0'};
   size_t info_len, code_len;
   char listmarker[LISTMARKER_SIZE];
-  char *emph_delim;
+  const char *emph_delim;
   bool first_in_list_item;
   bufsize_t marker_width;
   bool allow_wrap = renderer->width > 0 && !(CMARK_OPT_NOBREAKS & options) &&
@@ -189,14 +174,17 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
   // Don't adjust tight list status til we've started the list.
   // Otherwise we loose the blank line between a paragraph and
   // a following list.
-  if (!(node->type == CMARK_NODE_ITEM && node->prev == NULL && entering)) {
-    tmp = get_containing_block(node);
-    renderer->in_tight_list_item =
-        tmp && // tmp might be NULL if there is no containing block
-        ((tmp->type == CMARK_NODE_ITEM &&
-          cmark_node_get_list_tight(tmp->parent)) ||
-         (tmp && tmp->parent && tmp->parent->type == CMARK_NODE_ITEM &&
-          cmark_node_get_list_tight(tmp->parent->parent)));
+  if (entering) {
+    if (node->parent && node->parent->type == CMARK_NODE_ITEM) {
+      renderer->in_tight_list_item = node->parent->parent->as.list.tight;
+    }
+  } else {
+    if (node->type == CMARK_NODE_LIST) {
+      renderer->in_tight_list_item =
+        node->parent &&
+        node->parent->type == CMARK_NODE_ITEM &&
+        node->parent->parent->as.list.tight;
+    }
   }
 
   if (node->extension && node->extension->commonmark_render_func) {
@@ -225,8 +213,7 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
       // this ensures that a following indented code block or list will be
       // inteprereted correctly.
       CR();
-      // MBGJ: Do not output html in parser
-      //LIT("<!-- end list -->");
+      LIT("<!-- end list -->");
       BLANKLINE();
     }
     break;
@@ -235,13 +222,8 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
     if (cmark_node_get_list_type(node->parent) == CMARK_BULLET_LIST) {
       marker_width = 4;
     } else {
-      list_number = cmark_node_get_list_start(node->parent);
+      list_number = cmark_node_get_item_index(node);
       list_delim = cmark_node_get_list_delim(node->parent);
-      tmp = node;
-      while (tmp->prev) {
-        tmp = tmp->prev;
-        list_number += 1;
-      }
       // we ensure a width of at least 4 so
       // we get nice transition from single digits
       // to double
@@ -406,10 +388,12 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
     break;
 
   case CMARK_NODE_STRONG:
-    if (entering) {
-      LIT("**");
-    } else {
-      LIT("**");
+    if (node->parent == NULL || node->parent->type != CMARK_NODE_STRONG) {
+      if (entering) {
+        LIT("**");
+      } else {
+        LIT("**");
+      }
     }
     break;
 

lib/commonmarker/src/html.c

@@ -63,10 +63,16 @@ static bool S_put_footnote_backref(cmark_html_renderer *renderer, cmark_strbuf *
   if (renderer->written_footnote_ix >= renderer->footnote_ix)
     return false;
   renderer->written_footnote_ix = renderer->footnote_ix;
+  char m[32];
+  snprintf(m, sizeof(m), "%d", renderer->written_footnote_ix);
 
   cmark_strbuf_puts(html, "<a href=\"#fnref-");
   houdini_escape_href(html, node->as.literal.data, node->as.literal.len);
-  cmark_strbuf_puts(html, "\" class=\"footnote-backref\" data-footnote-backref aria-label=\"Back to content\">↩</a>");
+  cmark_strbuf_puts(html, "\" class=\"footnote-backref\" data-footnote-backref data-footnote-backref-idx=\"");
+  cmark_strbuf_puts(html, m);
+  cmark_strbuf_puts(html, "\" aria-label=\"Back to reference ");
+  cmark_strbuf_puts(html, m);
+  cmark_strbuf_puts(html, "\">↩</a>");
 
   if (node->footnote.def_count > 1)
   {
@@ -78,7 +84,15 @@ static bool S_put_footnote_backref(cmark_html_renderer *renderer, cmark_strbuf *
       houdini_escape_href(html, node->as.literal.data, node->as.literal.len);
       cmark_strbuf_puts(html, "-");
       cmark_strbuf_puts(html, n);
-      cmark_strbuf_puts(html, "\" class=\"footnote-backref\" data-footnote-backref aria-label=\"Back to content\">↩<sup class=\"footnote-ref\">");
+      cmark_strbuf_puts(html, "\" class=\"footnote-backref\" data-footnote-backref data-footnote-backref-idx=\"");
+      cmark_strbuf_puts(html, m);
+      cmark_strbuf_puts(html, "-");
+      cmark_strbuf_puts(html, n);
+      cmark_strbuf_puts(html, "\" aria-label=\"Back to reference ");
+      cmark_strbuf_puts(html, m);
+      cmark_strbuf_puts(html, "-");
+      cmark_strbuf_puts(html, n);
+      cmark_strbuf_puts(html, "\">↩<sup class=\"footnote-ref\">");
       cmark_strbuf_puts(html, n);
       cmark_strbuf_puts(html, "</sup></a>");
     }
@@ -350,10 +364,12 @@ static int S_render_node(cmark_html_renderer *renderer, cmark_node *node,
     break;
 
   case CMARK_NODE_STRONG:
-    if (entering) {
-      cmark_strbuf_puts(html, "<strong>");
-    } else {
-      cmark_strbuf_puts(html, "</strong>");
+    if (node->parent == NULL || node->parent->type != CMARK_NODE_STRONG) {
+      if (entering) {
+        cmark_strbuf_puts(html, "<strong>");
+      } else {
+        cmark_strbuf_puts(html, "</strong>");
+      }
     }
     break;