Use GC-safe version when setting elements.

src/runtime.cc

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@@ skipping 7373 matching lines @@
 
   int index;
   PropertyAttributes attributes;
   ContextLookupFlags flags = FOLLOW_CHAINS;
   Handle<Object> holder = context->Lookup(name, flags, &index, &attributes);
 
   if (index >= 0) {
     if (holder->IsContext()) {
       // Ignore if read_only variable.
       if ((attributes & READ_ONLY) == 0) {
         Handle<Context>::cast(holder)->set(index, *value);

[Mads Ager (chromium), 2011/02/09 07:03:36]

Do you know that this one cannot fail? Code that is a handle non-handle mix is
always scary. Let's do this one in a GC safe way as well.

[antonm, 2011/02/09 11:38:09]

Agree, but in this case I am afraid we cannot use SetElement as a context is a
fixed array actually.  Good news is set should be GC safe.  I slightly reworked
this line (to have lesser mixture of handles and non-handles stuff) and added a
comment explaining why it's safe.

On 2011/02/09 07:03:36, Mads Ager wrote:

       }
     } else {
       ASSERT((attributes & READ_ONLY) == 0);
-      Handle<JSObject>::cast(holder)->SetElement(index, *value)->
-          ToObjectUnchecked();
+      Handle<Object> result =
+          SetElement(Handle<JSObject>::cast(holder), index, value);
+      if (result.is_null()) return Failure::Exception();
     }
     return *value;
   }
 
   // Slow case: The property is not in a FixedArray context.
   // It is either in an JSObject extension context or it was not found.
   Handle<JSObject> context_ext;
 
   if (!holder.is_null()) {
     // The property exists in the extension context.
@@ skipping 3686 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal