Improve worst-case performance of inline.text regex

The old regex may take quadratic time to scan for potential line breaks or email addresses starting at every point. Fix it to avoid scanning from points that would have been in the middle of a previous scan. Signed-off-by: Anders Kaseorg <[email protected]>
markedjs · Apr 3, 2019 · 18dbc0b · 18dbc0b
1 parent ba1de1e
commit 18dbc0b
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diff --git a/lib/marked.js b/lib/marked.js
@@ -546,7 +546,7 @@ var inline = {
   code: /^(`+)([^`]|[^`][\s\S]*?[^`])\1(?!`)/,
   br: /^( {2,}|\\)\n(?!\s*$)/,
   del: noop,
-  text: /^(`+|[^`])[\s\S]*?(?=[\\<!\[`*]|\b_| {2,}\n|$)/
+  text: /^(`+|[^`])(?:[\s\S]*?(?:(?=[\\<!\[`*]|\b_|$)|[^ ](?= {2,}\n))|(?= {2,}\n))/
 };
 
 // list of punctuation marks from common mark spec
@@ -615,10 +615,7 @@ inline.gfm = merge({}, inline.normal, {
   url: /^((?:ftp|https?):\/\/|www\.)(?:[a-zA-Z0-9\-]+\.?)+[^\s<]*|^email/,
   _backpedal: /(?:[^?!.,:;*_~()&]+|\([^)]*\)|&(?![a-zA-Z0-9]+;$)|[?!.,:;*_~)]+(?!$))+/,
   del: /^~+(?=\S)([\s\S]*?\S)~+/,
-  text: edit(inline.text)
-    .replace(']|', '~]|')
-    .replace('|$', '|https?://|ftp://|www\\.|[a-zA-Z0-9.!#$%&\'*+/=?^_`{\\|}~-]+@|$')
-    .getRegex()
+  text: /^(`+|[^`])(?:[\s\S]*?(?:(?=[\\<!\[`*~]|\b_|https?:\/\/|ftp:\/\/|www\.|$)|[^ ](?= {2,}\n)|[^a-zA-Z0-9.!#$%&'*+\/=?_`{\|}~-](?=[a-zA-Z0-9.!#$%&'*+\/=?_`{\|}~-]+@))|(?= {2,}\n|[a-zA-Z0-9.!#$%&'*+\/=?_`{\|}~-]+@))/
 });
 
 inline.gfm.url = edit(inline.gfm.url, 'i')
@@ -630,7 +627,7 @@ inline.gfm.url = edit(inline.gfm.url, 'i')
 
 inline.breaks = merge({}, inline.gfm, {
   br: edit(inline.br).replace('{2,}', '*').getRegex(),
-  text: edit(inline.gfm.text).replace('{2,}', '*').getRegex()
+  text: edit(inline.gfm.text).replace('{2,}', '*').replace('{2,}', '*').getRegex()
 });
 
 /**

diff --git a/test/specs/gfm/gfm.0.28.json b/test/specs/gfm/gfm.0.28.json
@@ -141,8 +141,7 @@
     "section": "Autolinks",
     "html": "<p><a href=\"mailto:[email protected]\">[email protected]</a></p>\n<p><a href=\"mailto:[email protected]\">[email protected]</a>.</p>\n<p>[email protected]</p>\n<p>[email protected]_</p>",
     "markdown": "[email protected]\n\n[email protected].\n\n[email protected]\n\n[email protected]_",
-    "example": 607,
-    "shouldFail": true
+    "example": 607
   },
   {
     "section": "Disallowed Raw HTML",