* Fixed bug in handling of quantified look-aheads.

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index 7236cb42cc01e418d16814efc2789b6f2a2e83aa..4c8f4979360e4aad11b672cea6022a45b38189ee 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -527,7 +527,7 @@ class RegExpParser {
   void Advance(int dist);
   void Reset(int pos);
 
-  bool HasCharacterEscapes();
+  bool IsNonSimple();

[Christian Plesner Hansen, 2008/12/12 09:52:01]

You should generally avoid negative method names.  How about IsSimple()?

 
   int captures_started() { return captures_ == NULL ? 0 : captures_->length(); }
   int position() { return next_pos_ - 1; }
@@ -548,7 +548,7 @@ class RegExpParser {
   int next_pos_;
   FlatStringReader* in_;
   Handle<String>* error_;
-  bool has_character_escapes_;
+  bool non_simple_;

[Christian Plesner Hansen, 2008/12/12 09:52:01]

Ditto.

   ZoneList<RegExpCapture*>* captures_;
   bool is_scanned_for_captures_;
   // The capture count is only valid after we have scanned for captures.
@@ -3502,7 +3502,7 @@ RegExpParser::RegExpParser(FlatStringReader* in,
     next_pos_(0),
     in_(in),
     error_(error),
-    has_character_escapes_(false),
+    non_simple_(false),
     captures_(NULL),
     is_scanned_for_captures_(false),
     capture_count_(0),
@@ -3550,11 +3550,10 @@ void RegExpParser::Advance(int dist) {
 }
 
 
-// Reports whether the parsed string atoms contain any characters that were
-// escaped in the original pattern. If not, all atoms are proper substrings
-// of the original pattern.
-bool RegExpParser::HasCharacterEscapes() {
-  return has_character_escapes_;
+// Reports whether the pattern might be used as a literal search string.
+// Only use if the result of the parse is a single atom node.
+bool RegExpParser::IsNonSimple() {

[Christian Plesner Hansen, 2008/12/12 09:52:01]

This should be a simple accessor, not a full camel case method.

+  return non_simple_;
 }
 
 RegExpTree* RegExpParser::ReportError(Vector<const char> message) {
@@ -3769,7 +3768,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
         Advance(2);
         break;
       }
-      has_character_escapes_ = true;
+      non_simple_ = true;
       break;
     case '{': {
       int dummy;
@@ -3822,6 +3821,7 @@ RegExpTree* RegExpParser::ParseDisjunction() {
       is_greedy = false;
       Advance();
     }
+    non_simple_ = true;  // Adding quantifier might *remove* look-ahead.
     builder.AddQuantifierToAtom(min, max, is_greedy);
   }
 }
@@ -4314,7 +4314,7 @@ bool ParseRegExp(FlatStringReader* input,
   } else {
     ASSERT(result->tree != NULL);
     ASSERT(result->error.is_null());
-    result->has_character_escapes = parser.HasCharacterEscapes();
+    result->non_simple = parser.IsNonSimple();
     result->capture_count = parser.captures_started();
   }
   return !parser.failed();