Fix crash: handle all flat string types in regexp replace.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index e3a150d907419a10273d1cd8923d6566e1973811..f81bb8627f9f16b0ef3d8006cec5d668757cf0ff 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -2284,8 +2284,9 @@ static Object* StringReplaceRegExpWithString(String* subject,
   return *(builder.ToString());
 }
 
+
 template <typename ResultSeqString>
-static Object* StringReplaceRegExpWithEmptyString(ResultSeqString* subject,
+static Object* StringReplaceRegExpWithEmptyString(String* subject,
                                                   JSRegExp* regexp,
                                                   JSArray* last_match_info) {
   ASSERT(subject->IsFlat());
@@ -2320,9 +2321,8 @@ static Object* StringReplaceRegExpWithEmptyString(ResultSeqString* subject,
   if (new_length == 0) {
     return Heap::empty_string();
   }
-  // TODO(sandholm) try to use types statically to determine this.
   Handle<ResultSeqString> answer;
-  if (subject_handle->IsAsciiRepresentation()) {
+  if (ResultSeqString::kHasAsciiEncoding) {
     answer =
         Handle<ResultSeqString>::cast(Factory::NewRawAsciiString(new_length));
   } else {
@@ -2440,14 +2440,12 @@ static Object* Runtime_StringReplaceRegExpWithString(Arguments args) {
   ASSERT(last_match_info->HasFastElements());
 
   if (replacement->length() == 0) {
-    if (subject->IsAsciiRepresentation()) {
-      return StringReplaceRegExpWithEmptyString(SeqAsciiString::cast(subject),
-                                                regexp,
-                                                last_match_info);
+    if (subject->IsAsciiRepresentation() || subject->HasOnlyAsciiChars()) {

[Lasse Reichstein, 2010/07/06 12:09:36]

Does subject->IsAsciiRepresentation() imply subject->HasOnlyAsciiChars()? (I.e.,
could we do with just HasOnlyAsciiChars?)

[Vitaly Repeshko, 2010/07/06 12:22:39]

Done.

+      return StringReplaceRegExpWithEmptyString<SeqAsciiString>(
+          subject, regexp, last_match_info);
     } else {
-      return StringReplaceRegExpWithEmptyString(SeqTwoByteString::cast(subject),
-                                                regexp,
-                                                last_match_info);
+      return StringReplaceRegExpWithEmptyString<SeqTwoByteString>(
+          subject, regexp, last_match_info);
     }
   }