157083 2016-04-27 10:29:16 -0700 Assertion failure for Reflect.get with Proxy and explicit receiver object 2016-05-26 05:16:19 -0700 1 1 1 Unclassified WebKit JavaScriptCore WebKit Local Build Unspecified Unspecified RESOLVED DUPLICATE 157080 P2 Normal --- 1 andre.bargull webkit-unassigned ggaren saam ysuzuki oldest_to_newest 1187795 0 andre.bargull 2016-04-27 10:29:16 -0700 SVN: rev200124 Build with: perl Tools/Scripts/build-jsc --gtk --debug The following test case triggers this assertion error: --- ASSERTION FAILED: prototype.isObject() --- Test case: --- Reflect.get(new Proxy({},{}), "x", {}) --- Stack trace: --- #0 0x00007ffff6e289ac in WTFCrash () at ../../Source/WTF/wtf/Assertions.cpp:322 #1 0x00007ffff6cf22a7 in JSC::performProxyGet (exec=0x7fffffffcae0, thisValue=140736127155904, propertyName=...) at ../../Source/JavaScriptCore/runtime/ProxyObject.cpp:112 #2 0x00007ffff6cebb4e in JSC::PropertySlot::customGetter (this=0x7fffffffca80, exec=0x7fffffffcae0, propertyName=...) at ../../Source/JavaScriptCore/runtime/PropertySlot.cpp:39 #3 0x00000000004423b2 in JSC::PropertySlot::getValue (this=0x7fffffffca80, exec=0x7fffffffcae0, propertyName=...) at ../../Source/JavaScriptCore/runtime/PropertySlot.h:294 #4 0x0000000000448cfb in JSC::JSValue::get (this=0x7fffffffca40, exec=0x7fffffffcae0, propertyName=..., slot=...) at ../../Source/JavaScriptCore/runtime/JSCJSValueInlines.h:768 #5 0x00007ffff6cfc288 in JSC::reflectObjectGet (exec=0x7fffffffcae0) at ../../Source/JavaScriptCore/runtime/ReflectObject.cpp:181 #6 0x00007fffb0bff028 in ?? () #7 0x00007fffffffcb60 in ?? () #8 0x00007ffff6a33818 in llint_entry () from /home/andre/svn/webkit/WebKitBuild/Debug/lib/libjavascriptcoregtk-4.0.so.18 Backtrace stopped: frame did not save the PC --- 1196698 1 ysuzuki 2016-05-26 05:16:19 -0700 Fixed by 157080. Thanks for your reporting. *** This bug has been marked as a duplicate of bug 157080 ***