Calling window.open("", "_self") allows working around restrictions on window.close()

[Ali Juma]

Windows that haven't been opened by script can't be closed using window.close(). However, calling |window.open("", "_self")| causes the existing window to be treated as if it's been opened by script, since in DOMWindow::createWindow we call |newFrame->page()->setOpenedByDOM();| without checking if this is really a newly-created frame.

This means that script can trivially workaround the restriction on window.close() by instead calling:
window.open("", "_self").close()

Neither Blink nor Gecko allows scripts to close windows this way.

[Ali Juma]

Created attachment 353388 [details]
Patch

[Chris Dumez]

Comment on attachment 353388 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=353388&action=review

r=me

> LayoutTests/fast/dom/Window/window-open-self-disallow-close.html:5
> +    <div id="log"></div>

Is this really needed?

[Ali Juma]

Created attachment 353396 [details]
Patch for landing

[Ali Juma]

(In reply to Chris Dumez from comment #2)
> Comment on attachment 353388 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=353388&action=review
> 
> r=me
> 
> > LayoutTests/fast/dom/Window/window-open-self-disallow-close.html:5
> > +    <div id="log"></div>
> 
> Is this really needed?

Not needed, removed now.

[WebKit Commit Bot]

Comment on attachment 353396 [details]
Patch for landing

Clearing flags on attachment: 353396

Committed r237598: <https://trac.webkit.org/changeset/237598>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/45677825>