72766 2011-11-18 15:18:47 -0800 Setting a property on an object whose prototype has a readonly property of the same name should not work 2012-03-01 02:20:24 -0800 1 1 1 Unclassified WebKit JavaScriptCore 528+ (Nightly build) Unspecified Unspecified RESOLVED DUPLICATE 79069 P2 Normal --- 1 bzbarsky webkit-unassigned barraclough jwalden+bwo oliver oldest_to_newest 506115 0 115885 bzbarsky 2011-11-18 15:18:47 -0800 Created attachment 115885 Testcase The attached testcase should print "PASS" twice. Instead, it prints "FAIL" twice in JavaScriptCore. The relevant analysis per ECMA-262 follows: 1) Per section 15.2.3.9, Object.freeze reconfigures data properties not be writable. 2) Per section 11.13.1, setting "test_instance.x = 'hello'" calls PutValue() with "test_instance.x" as the first argument. 3) Per section 8.7.2 step 4 the [[Put]] internal method of test_instance is called. IsStrictReference is true if an only if the code is in strict mode. 4) Per section 8.12.5 step 1, the [[CanPut]] internal method of test_instance is called. 5) Per section 8.12.4 step 1, [[GetOwnProperty]] is called on test_instance; in this case it returns undefined, so step 2 is skipped. 6) Per section 8.12.4 step 5 [[GetProperty]] is called on the prototype and returns a data descriptor for a non-writable data property. 7) Per section 8.12.4 step 8b, [[CanPut]] returns false. 8) Per section 8.12.5 step 1, either a TypeError is thrown or the set is ignored, depending on whether the code is in strict mode. JavaScriptCore most certainly doesn't do the above. SpiderMonkey gets this right. 506439 1 bzbarsky 2011-11-19 13:58:29 -0800 Step 2 should be: 2) Per section 11.13.1, setting "test_instance.x" calls PutValue() with "test_instance.x" as the first argument. 568487 2 barraclough 2012-03-01 02:20:24 -0800 This has been fixed in r108304. *** This bug has been marked as a duplicate of bug 79069 *** 115885 2011-11-18 15:18:47 -0800 2011-11-18 15:18:47 -0800 Testcase test.js text/plain 503 bzbarsky KGZ1bmN0aW9uICgpIHsKICAgIHZhciB0ZXN0ID0gZnVuY3Rpb24oKSB7IHJldHVybiB0aGlzOyB9 OwogICAgdGVzdC5wcm90b3R5cGUgPSB7IHg6ICdQQVNTJyB9OwogICAgT2JqZWN0LmZyZWV6ZSh0 ZXN0LnByb3RvdHlwZSk7CiAgICB2YXIgdGVzdF9pbnN0YW5jZSA9IG5ldyB0ZXN0OwogICAgdGVz dF9pbnN0YW5jZS54ICAgPSAnRkFJTCc7CiAgICBwcmludCh0ZXN0X2luc3RhbmNlLngpOwp9KSgp OwoKKGZ1bmN0aW9uICgpIHsKICAgICJ1c2Ugc3RyaWN0IjsKICAgIHZhciB0ZXN0ID0gZnVuY3Rp b24oKSB7IHJldHVybiB0aGlzOyB9OwogICAgdGVzdC5wcm90b3R5cGUgPSB7IHg6IDEgfTsKICAg IE9iamVjdC5mcmVlemUodGVzdC5wcm90b3R5cGUpOwogICAgdmFyIHRlc3RfaW5zdGFuY2UgPSBu ZXcgdGVzdDsKICAgIHRyeSB7Cgl0ZXN0X2luc3RhbmNlLnggICA9IDI7CglwcmludCgiRkFJTCIp OwogICAgfSBjYXRjaCAoZSkgewoJcHJpbnQoIlBBU1MiKTsKICAgIH0KfSkoKTs=