Bug 70207 – After deleting __defineSetter__, it is absent but appears in name list

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

[Mark S. Miller]

Below I delete __defineSetter__ on Object.prototype. Afterwards, it reappears on the end of the list returned by Object.getOwnPropertyNames but otherwise appears to be truly deleted.

This is a new problem, in that Safari Version 5.0.6 (5533.22.3) instead has the problem described by issue 61014, namely that delete reports that it successfully deleted __defineSetter__, but it seems to still be there in all the ways tested below. So is this a new bug introduced in trying to fix issue 61014 ?



> var gopn = Object.getOwnPropertyNames
> var gopd = Object.getOwnPropertyDescriptor
> gopn(Object.prototype)
constructor,__defineSetter__,valueOf,__lookupGetter__,toLocaleString,__defineGetter__,hasOwnProperty,propertyIsEnumerable,toString,__lookupSetter__,isPrototypeOf

> var desc = gopd(Object.prototype, '__defineSetter__')
> JSON.stringify(desc)
{"writable":true,"enumerable":false,"configurable":true}

> desc.value
function __defineSetter__() {
    [native code]
}

> delete Object.prototype.__defineSetter__;
true

> gopn(Object.prototype)
constructor,toString,valueOf,__lookupGetter__,toLocaleString,__defineGetter__,hasOwnProperty,propertyIsEnumerable,__lookupSetter__,isPrototypeOf,__defineSetter__

> var desc = gopd(Object.prototype, '__defineSetter__')
> desc === undefined
true

> Object.prototype.__defineSetter__ === undefined
true

> '__defineSetter__' in Object.prototype
false

[Mark S. Miller]

This occurs on WebKit Nightly r97567.

[Gavin Barraclough]

Ah, good catch, thank you Mark.
This will be related to r61014, the fix to that should be expanded to cover Object.getOwnPropertyNames - this should be easy to resolve.  I'll look into this.

[Gavin Barraclough]

Created attachment 111322 [details]
Fix

[WebKit Review Bot]

Attachment 111322 [details] did not pass style-queue:

Failed to run "['Tools/Scripts/update-webkit', '--chromium']" exit_code: 2

Updating OpenSource
Current branch master is up to date.
Updating chromium port dependencies using gclient...
Error: Can't switch the checkout to http://v8.googlecode.com/svn/branches/3.6@9637; UUID don't match and there is local changes in /mnt/git/webkit-style-queue/Source/WebKit/chromium/v8. Delete the directory and try again.
Re-trying 'depot_tools/gclient sync'
Error: Can't switch the checkout to http://v8.googlecode.com/svn/branches/3.6@9637; UUID don't match and there is local changes in /mnt/git/webkit-style-queue/Source/WebKit/chromium/v8. Delete the directory and try again.
Re-trying 'depot_tools/gclient sync'
Error: Can't switch the checkout to http://v8.googlecode.com/svn/branches/3.6@9637; UUID don't match and there is local changes in /mnt/git/webkit-style-queue/Source/WebKit/chromium/v8. Delete the directory and try again.
Error: 'depot_tools/gclient sync' failed 3 tries and returned 256 at Tools/Scripts/update-webkit-chromium line 107.
Re-trying 'depot_tools/gclient sync'
No such file or directory at Tools/Scripts/update-webkit line 104.


If any of these errors are false positives, please file a bug against check-webkit-style.

[Gavin Barraclough]

Fixed in r97655