Bug 250310 – CSS clip-path should prevent direct image compositing

• Component: CSS
• Status: RESOLVED INVALID

[Ahmad Saleem]

Hi Team,

While going through Blink's commit, I came cross another failing test case in Safari 16.2 & Safari Technology Preview 160 (while passing in Chrome Canary 111 & Firefox Nightly 110), I tried to look for related bug but couldn't find (it could be silly me here):

Test Case - https://jsfiddle.net/sjmanpte/

^ Hover and it will be different black while in Chrome etc., it would be turning into greyish + light greenish.

Blink Commit - https://chromium.googlesource.com/chromium/blink/+/f952e432e1e936b068eed89fbc567ee2a261aa58

WebKit Source - https://searchfox.org/wubkat/source/Source/WebCore/rendering/RenderLayerBacking.cpp#2988

adding "|| renderer().hasClipPath())" into above.

Just wanted to raise it so this can be fixed.

Thanks!

[Simon Fraser (smfr)]

The testcase renders correctly in WebKit so I'm not sure we need the change.

[Ahmad Saleem]

Created attachment 464427 [details]
Safari 16.2, Chrome Canary 111 & Firefox Nightly 110 - difference

@smfr - I am getting this on my end, you checked with WebKit Trunk build?

[Simon Fraser (smfr)]

In a recent WebKit build (and STP 160) I see the same as the CHrome/Firefox behavior; the circle gets more transparent as it zooms up.

[Ahmad Saleem]

(In reply to Simon Fraser (smfr) from comment #3)
> In a recent WebKit build (and STP 160) I see the same as the CHrome/Firefox
> behavior; the circle gets more transparent as it zooms up.

For some reason, I have same behavior in STP160 and Safari 16.2 and similar to attached video. Strange! :-(

[Ahmad Saleem]

(In reply to Ahmad Saleem from comment #4)
> (In reply to Simon Fraser (smfr) from comment #3)
> > In a recent WebKit build (and STP 160) I see the same as the CHrome/Firefox
> > behavior; the circle gets more transparent as it zooms up.
> 
> For some reason, I have same behavior in STP160 and Safari 16.2 and similar
> to attached video. Strange! :-(

If I use incognito mode then I get same as Chrome Canary 111 and Firefox Nightly 110 using even Safari 16.2. So it might be cache issue?

[Radar WebKit Bug Importer]

<rdar://problem/104294888>

[Antti Koivisto]

I can't repro this with WebKit trunk.

[Ahmad Saleem]

Let's mark this as "RESOLVED INVALID" since others are not able to reproduce and no need to loss our time here. :-)