Fix store_mode bug involving polymorphism with external and JS arrays.

src/ic.cc

 // Copyright 2012 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 1753 matching lines @@
     if (store_mode == STANDARD_STORE) {
       store_mode = old_store_mode;
     } else if (store_mode != old_store_mode) {
       TRACE_GENERIC_IC(isolate(), "KeyedIC", "store mode mismatch");
       return strict_mode == kStrictMode
           ? generic_stub_strict()
           : generic_stub();
     }
   }
 
+  // If the store mode isn't the standard mode, make sure that all polymorphic
+  // receivers are either external arrays, or all "normal" arrays. Otherwise,
+  // use the generic stub.
+  if (store_mode != STANDARD_STORE) {
+    int external_arrays = 0;
+    for (int i = 0; i < target_receiver_maps.length(); ++i) {
+      if (target_receiver_maps[i]->has_external_array_elements()) {
+        external_arrays++;
+      }
+    }
+    if (external_arrays != 0 &&
+        external_arrays != target_receiver_maps.length()) {
+      TRACE_GENERIC_IC(isolate(), "KeyedIC",
+          "unsupported combination of external and normal arrays");
+      return strict_mode == kStrictMode
+          ? generic_stub_strict()
+          : generic_stub();
+    }
+  }
+
   return isolate()->stub_cache()->ComputeStoreElementPolymorphic(
       &target_receiver_maps, store_mode, strict_mode);
 }
 
 
 Handle<Map> KeyedStoreIC::ComputeTransitionedMap(
     Handle<JSObject> receiver,
     KeyedAccessStoreMode store_mode) {
   switch (store_mode) {
     case STORE_TRANSITION_SMI_TO_OBJECT:
@@ skipping 992 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal