Merge pull request from GHSA-r8vr-c48j-fcc5

Fix quadratic behavior in rendering
github · Mar 31, 2023 · 07a66c9 · 07a66c9
2 parents 2300c1b + bd4f96e
commit 07a66c9
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Showing 10 changed files with 80 additions and 100 deletions.
diff --git a/src/commonmark.c b/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;
@@ -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) {
@@ -228,19 +216,15 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
       LIT("<!-- end list -->");
       BLANKLINE();
     }
+    renderer->list_number = cmark_node_get_list_start(node);
     break;
 
   case CMARK_NODE_ITEM:
     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 = renderer->list_number++;
       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
@@ -405,10 +389,12 @@ 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;
 

diff --git a/src/html.c b/src/html.c
@@ -364,10 +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;
 

diff --git a/src/latex.c b/src/latex.c
@@ -385,10 +385,12 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
     break;
 
   case CMARK_NODE_STRONG:
-    if (entering) {
-      LIT("\\textbf{");
-    } else {
-      LIT("}");
+    if (node->parent == NULL || node->parent->type != CMARK_NODE_STRONG) {
+      if (entering) {
+        LIT("\\textbf{");
+      } else {
+        LIT("}");
+      }
     }
     break;
 

diff --git a/src/man.c b/src/man.c
@@ -74,7 +74,6 @@ static void S_outc(cmark_renderer *renderer, cmark_node *node,
 
 static int S_render_node(cmark_renderer *renderer, cmark_node *node,
                          cmark_event_type ev_type, int options) {
-  cmark_node *tmp;
   int list_number;
   bool entering = (ev_type == CMARK_EVENT_ENTER);
   bool allow_wrap = renderer->width > 0 && !(CMARK_OPT_NOBREAKS & options);
@@ -114,6 +113,7 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
     break;
 
   case CMARK_NODE_LIST:
+    renderer->list_number = cmark_node_get_list_start(node);
     break;
 
   case CMARK_NODE_ITEM:
@@ -123,12 +123,7 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
       if (cmark_node_get_list_type(node->parent) == CMARK_BULLET_LIST) {
         LIT("\\[bu] 2");
       } else {
-        list_number = cmark_node_get_list_start(node->parent);
-        tmp = node;
-        while (tmp->prev) {
-          tmp = tmp->prev;
-          list_number += 1;
-        }
+        list_number = renderer->list_number++;
         char list_number_s[LIST_NUMBER_SIZE];
         snprintf(list_number_s, LIST_NUMBER_SIZE, "\"%d.\" 4", list_number);
         LIT(list_number_s);
@@ -225,10 +220,12 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
     break;
 
   case CMARK_NODE_STRONG:
-    if (entering) {
-      LIT("\\f[B]");
-    } else {
-      LIT("\\f[]");
+    if (node->parent == NULL || node->parent->type != CMARK_NODE_STRONG) {
+      if (entering) {
+        LIT("\\f[B]");
+      } else {
+        LIT("\\f[]");
+      }
     }
     break;
 

diff --git a/src/node.h b/src/node.h
@@ -83,6 +83,14 @@ struct cmark_node {
 
   cmark_syntax_extension *extension;
 
+  /**
+   * Used during cmark_render() to cache the most recent non-NULL
+   * extension, if you go up the parent chain like this:
+   *
+   * node->parent->...parent->extension
+   */
+  cmark_syntax_extension *ancestor_extension;
+
   union {
     int ref_ix;
     int def_count;

diff --git a/src/plaintext.c b/src/plaintext.c
@@ -16,23 +16,8 @@ static CMARK_INLINE void outc(cmark_renderer *renderer, cmark_node *node,
   cmark_render_code_point(renderer, c);
 }
 
-// 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 i;
@@ -46,14 +31,17 @@ 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->plaintext_render_func) {
@@ -73,19 +61,15 @@ static int S_render_node(cmark_renderer *renderer, cmark_node *node,
                                     node->next->type == CMARK_NODE_LIST)) {
       CR();
     }
+    renderer->list_number = cmark_node_get_list_start(node);
     break;
 
   case CMARK_NODE_ITEM:
     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 = renderer->list_number++;
       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

diff --git a/src/render.c b/src/render.c
@@ -31,13 +31,7 @@ static void S_out(cmark_renderer *renderer, cmark_node *node,
   cmark_chunk remainder = cmark_chunk_literal("");
   int k = renderer->buffer->size - 1;
 
-  cmark_syntax_extension *ext = NULL;
-  cmark_node *n = node;
-  while (n && !ext) {
-    ext = n->extension;
-    if (!ext)
-      n = n->parent;
-  }
+  cmark_syntax_extension *ext = node->ancestor_extension;
   if (ext && !ext->commonmark_escape_func)
     ext = NULL;
 
@@ -177,11 +171,16 @@ char *cmark_render(cmark_mem *mem, cmark_node *root, int options, int width,
 
   cmark_renderer renderer = {mem,   &buf, &pref, 0,           width,
                              0,     0,    true,  true,        false,
-                             false, outc, S_cr,  S_blankline, S_out,
-                             0};
+                             false, 0,    outc,  S_cr,        S_blankline,
+                             S_out, 0};
 
   while ((ev_type = cmark_iter_next(iter)) != CMARK_EVENT_DONE) {
     cur = cmark_iter_get_node(iter);
+    if (cur->extension) {
+      cur->ancestor_extension = cur->extension;
+    } else if (cur->parent) {
+      cur->ancestor_extension = cur->parent->ancestor_extension;
+    }
     if (!render_node(&renderer, cur, ev_type, options)) {
       // a false value causes us to skip processing
       // the node's contents.  this is used for

diff --git a/src/render.h b/src/render.h
@@ -23,6 +23,7 @@ struct cmark_renderer {
   bool begin_content;
   bool no_linebreaks;
   bool in_tight_list_item;
+  int list_number;
   void (*outc)(struct cmark_renderer *, cmark_node *, cmark_escaping, int32_t, unsigned char);
   void (*cr)(struct cmark_renderer *);
   void (*blankline)(struct cmark_renderer *);

diff --git a/src/xml.c b/src/xml.c
@@ -11,6 +11,7 @@
 #include "syntax_extension.h"
 
 #define BUFFER_SIZE 100
+#define MAX_INDENT 40
 
 // Functions to convert cmark_nodes to XML strings.
 
@@ -26,7 +27,7 @@ struct render_state {
 
 static CMARK_INLINE void indent(struct render_state *state) {
   int i;
-  for (i = 0; i < state->indent; i++) {
+  for (i = 0; i < state->indent && i < MAX_INDENT; i++) {
     cmark_strbuf_putc(state->xml, ' ');
   }
 }

diff --git a/test/spec.txt b/test/spec.txt
@@ -6926,7 +6926,7 @@ foo__bar__
 ```````````````````````````````` example
 __foo, __bar__, baz__
 .
-<p><strong>foo, <strong>bar</strong>, baz</strong></p>
+<p><strong>foo, bar, baz</strong></p>
 ````````````````````````````````
 
 
@@ -7197,7 +7197,7 @@ foo***bar***baz
 ```````````````````````````````` example
 foo******bar*********baz
 .
-<p>foo<strong><strong><strong>bar</strong></strong></strong>***baz</p>
+<p>foo<strong>bar</strong>***baz</p>
 ````````````````````````````````
 
 
@@ -7268,21 +7268,21 @@ __foo _bar_ baz__
 ```````````````````````````````` example
 __foo __bar__ baz__
 .
-<p><strong>foo <strong>bar</strong> baz</strong></p>
+<p><strong>foo bar baz</strong></p>
 ````````````````````````````````
 
 
 ```````````````````````````````` example
 ____foo__ bar__
 .
-<p><strong><strong>foo</strong> bar</strong></p>
+<p><strong>foo bar</strong></p>
 ````````````````````````````````
 
 
 ```````````````````````````````` example
 **foo **bar****
 .
-<p><strong>foo <strong>bar</strong></strong></p>
+<p><strong>foo bar</strong></p>
 ````````````````````````````````
 
 
@@ -7567,14 +7567,14 @@ switching delimiters:
 ```````````````````````````````` example
 ****foo****
 .
-<p><strong><strong>foo</strong></strong></p>
+<p><strong>foo</strong></p>
 ````````````````````````````````
 
 
 ```````````````````````````````` example
 ____foo____
 .
-<p><strong><strong>foo</strong></strong></p>
+<p><strong>foo</strong></p>
 ````````````````````````````````
 
 
@@ -7585,7 +7585,7 @@ delimiters:
 ```````````````````````````````` example
 ******foo******
 .
-<p><strong><strong><strong>foo</strong></strong></strong></p>
+<p><strong>foo</strong></p>
 ````````````````````````````````
 
 
@@ -7601,7 +7601,7 @@ Rule 14:
 ```````````````````````````````` example
 _____foo_____
 .
-<p><em><strong><strong>foo</strong></strong></em></p>
+<p><em><strong>foo</strong></em></p>
 ````````````````````````````````