Bug 86461 – Property names of the built-in object cannot be retrieved after trying to delete one of its properties

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Hojong Han]

[Script]
delete navigator.geolocation;
	
for (var prop in navigator) {
	document.write("name: " + prop + "; value: " + navigator[prop], "<br>");
}

[Actual Result]
name: javaEnabled; value: function javaEnabled() { [native code] }
name: getStorageUpdates; value: function getStorageUpdates() { [native code] }

====================================================================================

I think the result of that script should be like below.
because geolocation cannot be removed since it has "DontDelete | ReadOnly" attribute
and properties of navigator nothing changed at last.

[Expected Result]
name: geolocation; value: [object Geolocation]
name: cookieEnabled; value: true
name: language; value: ko-KR
name: productSub; value: 20030107
name: product; value: Gecko
name: appCodeName; value: Mozilla
name: mimeTypes; value: [object MimeTypeArray]
name: vendorSub; value: 
name: vendor; value: Apple Computer, Inc.
name: platform; value: Win32
name: appName; value: Netscape
name: appVersion; value: 5.0 (Windows NT 5.1) AppleWebKit/534+ (KHTML, like Gecko) Version/5.0.3 Safari/533.19.4
name: userAgent; value: Mozilla/5.0 (Windows NT 5.1) AppleWebKit/534+ (KHTML, like Gecko) Version/5.0.3 Safari/533.19.4
name: plugins; value: [object PluginArray]
name: onLine; value: true
name: javaEnabled; value: function javaEnabled() { [native code] }
name: getStorageUpdates; value: function getStorageUpdates() { [native code] }


This issue is occurred after setStaticFunctionsReified().
It blocks an object from calling getClassPropertyNames method.

Any comment welcomed...

[Hojong Han]

Created attachment 145557 [details]
Patch

[Gavin Barraclough]

Hi, the fix looks great, but we do ask that changes are accompanied by a layout test – would it be possible to add one?

The appropriate place to test this is likely in LayoutTests/fast/js, you can add a test case to an appropriate existing test, or create a new test by copying an existing .html and corresponding .js.

Many thanks,
G.

[Hojong Han]

Created attachment 146787 [details]
Patch

[WebKit Review Bot]

Comment on attachment 146787 [details]
Patch

Attachment 146787 [details] did not pass chromium-ews (chromium-xvfb):
Output: http://queues.webkit.org/results/12925913

New failing tests:
fast/js/delete-syntax.html

[WebKit Review Bot]

Created attachment 146818 [details]
Archive of layout-test-results from ec2-cr-linux-04

The attached test failures were seen while running run-webkit-tests on the chromium-ews.
Bot: ec2-cr-linux-04  Port: <class 'webkitpy.common.config.ports.ChromiumXVFBPort'>  Platform: Linux-2.6.35-28-virtual-x86_64-with-Ubuntu-10.10-maverick

[Hojong Han]

Created attachment 146821 [details]
Patch

[Gavin Barraclough]

*** Bug 88403 has been marked as a duplicate of this bug. ***

[Gavin Barraclough]

Comment on attachment 146821 [details]
Patch

Thanks for adding the layout test Hojong, this looks great.

[WebKit Review Bot]

Comment on attachment 146821 [details]
Patch

Clearing flags on attachment: 146821

Committed r120045: <http://trac.webkit.org/changeset/120045>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.

[Hojong Han]

(In reply to comment #8)
> (From update of attachment 146821 [details])
> Thanks for adding the layout test Hojong, this looks great.

Really thanks for review Gavin.

There's one thing I'm curious is that how to delete static built-in properties, not function. 
JSObject::deleteProperty does nothing but return true for "Deletable" built-in properties and there's comment like "// FIXME: Should the code here actually do some deletion?".
Are you working on this to figure out?