Less intrusive patch for regexp bug.

src/regexp.js

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 179 matching lines @@
   }
 
   var cache = regExpCache;
   var saveAnswer = false;
 
   if (%_ObjectEquals(cache.type, 'exec') &&
       %_ObjectEquals(cache.lastIndex, this.lastIndex) &&
       %_ObjectEquals(cache.regExp, this) &&
       %_ObjectEquals(cache.subject, string)) {
     if (cache.answerSaved) {
-      if (this.global) this.lastIndex = 0;
       return CloneRegExpResult(cache.answer);
     } else {
       saveAnswer = true;
     }
   }
 
   if (%_ArgumentsLength() == 0) {
     var regExpInput = LAST_INPUT(lastMatchInfo);
     if (IS_UNDEFINED(regExpInput)) {
       throw MakeError('no_input_to_regexp', [this]);
@@ skipping 13 matching lines @@
   if (i < 0 || i > s.length) {
     this.lastIndex = 0;
     return null;
   }
 
   %_Log('regexp', 'regexp-exec,%0r,%1S,%2i', [this, s, lastIndex]);
   // matchIndices is either null or the lastMatchInfo array.
   var matchIndices = %_RegExpExec(this, s, i, lastMatchInfo);
 
   if (matchIndices == null) {
-    if (this.global) this.lastIndex = 0;
+    if (this.global) {
+      this.lastIndex = 0;
+      if (lastIndex != 0) return matchIndices;
+    }
     cache.lastIndex = lastIndex;
     cache.regExp = this;
     cache.subject = s;
     cache.answer = matchIndices;  // Null.
     cache.answerSaved = true;     // Safe since no cloning is needed.
     cache.type = 'exec';
     return matchIndices;        // No match.
   }
   lastMatchInfoOverride = null;
   var result = BuildResultFromMatchInfo(matchIndices, s);
@@ skipping 293 matching lines @@
   %DefineAccessor($RegExp, "$'", SETTER, NoOpSetter, DONT_ENUM | DONT_DELETE);
 
   for (var i = 1; i < 10; ++i) {
     %DefineAccessor($RegExp, '$' + i, GETTER, RegExpMakeCaptureGetter(i), DONT_DELETE);
     %DefineAccessor($RegExp, '$' + i, SETTER, NoOpSetter, DONT_DELETE);
   }
 }
 
 
 SetupRegExp();