RegExp: Fix caching to correctly set lastIndex.

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 168 matching lines @@
   }
 
   var cache = regExpCache;
   var saveAnswer = false;
 
   if (%_ObjectEquals(cache.type, 'exec') &&
       %_ObjectEquals(cache.lastIndex, this.lastIndex) &&
       %_IsRegExpEquivalent(cache.regExp, this) &&
       %_ObjectEquals(cache.subject, string)) {
     if (cache.answerSaved) {
+      // If this regexp is not global, cache.lastIndex is zero, so we only get 
+      // here if this.lastIndex is zero, and resulting this.lastIndex
+      // must be zero too, so no change is necessary.
+      if (this.global) this.lastIndex = lastMatchInfo[CAPTURE1];
       return %_RegExpCloneResult(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 76 matching lines @@
   } else {
     s = ToString(string);
   }
 
   var lastIndex = this.lastIndex;
   var cache = regExpCache;
   if (%_ObjectEquals(cache.type, 'test') &&
       %_IsRegExpEquivalent(cache.regExp, this) &&
       %_ObjectEquals(cache.subject, string) &&
       %_ObjectEquals(cache.lastIndex, lastIndex)) {
+    // If this regexp is not global, cache.lastIndex is zero, so we only get 
+    // here if this.lastIndex is zero, and resulting this.lastIndex
+    // must be zero too, so no change is necessary.
+    if (this.global) this.lastIndex = lastMatchInfo[CAPTURE1];
     return cache.answer;
   }
 
   // Remove irrelevant preceeding '.*' in a test regexp. The expression
   // checks whether this.source starts with '.*' and that the third
   // char is not a '?'
   if (%_StringCharCodeAt(this.source,0) == 46 && // '.'
       %_StringCharCodeAt(this.source,1) == 42 && // '*'
       %_StringCharCodeAt(this.source,2) != 63) { // '?'
     if (!%_ObjectEquals(regexp_key, this)) {
@@ skipping 234 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();