Commit 25228d5d5c335b38af14d36bcaffb92a684feb25
2017-01-08T09:25:10
md_is_link_destination_B: Apply new spec rules for parenthesis. The specification now allows nesting parenthesis inside a link destination as long as opening and closing ones are balanced.
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diff --git a/md4c/md4c.c b/md4c/md4c.c
index 08a61a5..0b10c72 100644
--- a/md4c/md4c.c
+++ b/md4c/md4c.c
@@ -1960,7 +1960,7 @@ 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 in_parentheses = 0;
+ int parenthesis_level = 0;
while(off < max_end) {
if(CH(off) == _T('\\') && off+1 < max_end && ISPUNCT(off+1)) {
@@ -1971,24 +1971,23 @@ md_is_link_destination_B(MD_CTX* ctx, OFF beg, OFF max_end, OFF* p_end,
if(ISWHITESPACE(off) || ISCNTRL(off))
break;
- /* Link destination may include balanced pair of unescaped '(' ')'
- * but only if they are not nested. */
+ /* 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('(')) {
- if(in_parentheses)
+ parenthesis_level++;
+ if(parenthesis_level > 32)
return FALSE;
- else
- in_parentheses = 1;
} else if(CH(off) == _T(')')) {
- if(in_parentheses)
- in_parentheses = 0;
- else
+ if(parenthesis_level == 0)
break;
+ parenthesis_level--;
}
off++;
}
- if(in_parentheses || off == beg)
+ if(parenthesis_level != 0 || off == beg)
return FALSE;
/* Success. */