* Fixed bug in handling of quantified look-aheads.

src/jsregexp.cc

Index: src/jsregexp.cc
diff --git a/src/jsregexp.cc b/src/jsregexp.cc
index 5f4f6bda51f2d1870156edb056499cf2f0ac9755..365ecb598bddc0621d0d7fd73ecb99f91ae740d4 100644
--- a/src/jsregexp.cc
+++ b/src/jsregexp.cc
@@ -271,8 +271,10 @@ Handle<Object> RegExpImpl::Compile(Handle<JSRegExp> re,
       return Handle<Object>::null();
     }
     RegExpAtom* atom = parse_result.tree->AsAtom();
-    if (atom != NULL && !flags.is_ignore_case()) {
-      if (parse_result.has_character_escapes) {
+    if (atom != NULL &&
+        !flags.is_ignore_case() &&
+        parse_result.capture_count == 0) {
+      if (parse_result.non_simple) {
         Vector<const uc16> atom_pattern = atom->data();
         Handle<String> atom_string =
             Factory::NewStringFromTwoByte(atom_pattern);