Inserted a missing string encoding check in lastIndexOf.

src/runtime.cc

 // Copyright 2011 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 3145 matching lines @@
     return Smi::FromInt(start_index);
   }
 
   if (!sub->IsFlat()) FlattenString(sub);
   if (!pat->IsFlat()) FlattenString(pat);
 
   AssertNoAllocation no_heap_allocation;  // ensure vectors stay valid
 
   int position = -1;
 
-  if (pat->IsAsciiRepresentation()) {
-    Vector<const char> pat_vector = pat->ToAsciiVector();
-    if (sub->IsAsciiRepresentation()) {
-      position = StringMatchBackwards(sub->ToAsciiVector(),
+  String* seq_sub = *sub;
+  // Extract flattened substrings of cons strings before determining asciiness.

[Vitaly Repeshko, 2011/08/22 13:37:46]

nit: Move the comment one line above.

+  if (seq_sub->IsConsString()) seq_sub = ConsString::cast(seq_sub)->first();
+  String* seq_pat = *pat;
+  if (seq_pat->IsConsString()) seq_pat = ConsString::cast(seq_pat)->first();
+
+  if (seq_pat->IsAsciiRepresentation()) {
+    Vector<const char> pat_vector = seq_pat->ToAsciiVector();
+    if (seq_sub->IsAsciiRepresentation()) {
+      position = StringMatchBackwards(seq_sub->ToAsciiVector(),
                                       pat_vector,
                                       start_index);
     } else {
-      position = StringMatchBackwards(sub->ToUC16Vector(),
+      position = StringMatchBackwards(seq_sub->ToUC16Vector(),
                                       pat_vector,
                                       start_index);
     }
   } else {
-    Vector<const uc16> pat_vector = pat->ToUC16Vector();
-    if (sub->IsAsciiRepresentation()) {
-      position = StringMatchBackwards(sub->ToAsciiVector(),
+    Vector<const uc16> pat_vector = seq_pat->ToUC16Vector();
+    if (seq_sub->IsAsciiRepresentation()) {
+      position = StringMatchBackwards(seq_sub->ToAsciiVector(),
                                       pat_vector,
                                       start_index);
     } else {
-      position = StringMatchBackwards(sub->ToUC16Vector(),
+      position = StringMatchBackwards(seq_sub->ToUC16Vector(),
                                       pat_vector,
                                       start_index);
     }
   }
 
   return Smi::FromInt(position);
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_StringLocaleCompare) {
@@ skipping 9715 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal