Fix set variable value bug: a function argument must be updated in 2 places

src/runtime.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 10816 matching lines @@
                                   Handle<Object> new_value) {
   if (inlined_jsframe_index != 0 || frame->is_optimized()) {
     // Optimized frames are not supported.
     return false;
   }
 
   Handle<JSFunction> function(JSFunction::cast(frame->function()));
   Handle<SharedFunctionInfo> shared(function->shared());
   Handle<ScopeInfo> scope_info(shared->scope_info());
 
+  bool default_result = false;
+
   // Parameters.
   for (int i = 0; i < scope_info->ParameterCount(); ++i) {
     if (scope_info->ParameterName(i)->Equals(*variable_name)) {
       frame->SetParameterValue(i, *new_value);
-      return true;
+      // Argument might be shadowed in heap context, don't stop here.
+      default_result = true;
     }
   }
 
   // Stack locals.
   for (int i = 0; i < scope_info->StackLocalCount(); ++i) {
     if (scope_info->StackLocalName(i)->Equals(*variable_name)) {
       frame->SetExpression(i, *new_value);
       return true;
     }
   }
@@ skipping 21 matching lines @@
                       variable_name,
                       new_value,
                       NONE,
                       kNonStrictMode);
           return true;
         }
       }
     }
   }
 
-  return false;
+  return default_result;
 }
 
 
 // Create a plain JSObject which materializes the closure content for the
 // context.
 static Handle<JSObject> MaterializeClosure(Isolate* isolate,
                                            Handle<Context> context) {
   ASSERT(context->IsFunctionContext());
 
   Handle<SharedFunctionInfo> shared(context->closure()->shared());
@@ skipping 2730 matching lines @@
     // 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(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal