Changeset 188384 in webkit for trunk/Source/JavaScriptCore/runtime/JSGlobalObjectFunctions.cpp

Timestamp:

Aug 13, 2015, 10:25:01 AM (10 years ago)

Author:

Yusuke Suzuki

Message:

X.SetPrototypeOf(Y) should succeed if X.Prototype is already Y even if X is not extensible
​https://bugs.webkit.org/show_bug.cgi?id=147930

Reviewed by Saam Barati.

When the passed prototype object to be set is the same to the existing
prototype object, SetPrototypeOf just finishes its operation even
if the extensibility of the target object is false.

• runtime/JSGlobalObjectFunctions.cpp:

(JSC::globalFuncProtoSetter):

• runtime/ObjectConstructor.cpp:

(JSC::objectConstructorSetPrototypeOf):

• runtime/ReflectObject.cpp:

(JSC::reflectObjectSetPrototypeOf):

• tests/stress/set-same-prototype.js: Added.

(shouldBe):
(shouldThrow):

File:

• trunk/Source/JavaScriptCore/runtime/JSGlobalObjectFunctions.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/runtime/JSGlobalObjectFunctions.cpp

@@ -875 +875 @@
         return JSValue::encode(jsUndefined());
 
+    if (thisObject->prototype() == value)
+        return JSValue::encode(jsUndefined());
+
     if (!thisObject->isExtensible())
         return throwVMError(exec, createTypeError(exec, StrictModeReadonlyPropertyWriteError));