Bug 213110 - REGRESSION (r262124): Twitter videos go blank after exiting fullscreen
Summary: REGRESSION (r262124): Twitter videos go blank after exiting fullscreen
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: Safari Technology Preview
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Sergio Villar Senin
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2020-06-11 20:29 PDT by Simon Fraser (smfr)
Modified: 2020-09-01 12:18 PDT (History)
19 users (show)

See Also:

Attachments
Patch (6.69 KB, patch)
2020-06-18 13:26 PDT, Sergio Villar Senin 		no flags Details | Formatted Diff | Diff
Patch (6.83 KB, patch)
2020-06-22 05:24 PDT, Sergio Villar Senin 		darin: review+
Details | Formatted Diff | Diff
Show Obsolete (1) View All Add an attachment (proposed patch, testcase, etc.)

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Description Simon Fraser (smfr) 2020-06-11 20:29:13 PDT 
Summary:
Twitter videos go blank after exiting fullscreen

Steps To Reproduce:
1. Load https://twitter.com/stephentyrone/status/1271230268762992642 in Safari
2. Take the video fullscreen
3. Exit fullscreen

Results:
The area where the video should be is blank.

Regression:
I regressed this to https://trac.webkit.org/changeset/262124/webkit
Comment 1 Sergio Villar Senin 2020-06-12 00:53:28 PDT 
We'll check. It's weird because I cannot reproduce it with WebKitGTK
Comment 2 Peng Liu 2020-06-12 16:25:22 PDT 
Is FULLSCREEN_API enabled for WebKitGTK? Looks like it is not. Then this issue affects Mac version only.
Comment 3 Peng Liu 2020-06-12 16:26:55 PDT 
<rdar://problem/64282632>
Comment 4 Simon Fraser (smfr) 2020-06-12 17:54:29 PDT 
Can we revert the change for now?
Comment 5 Sergio Villar Senin 2020-06-14 22:57:53 PDT 
(In reply to Simon Fraser (smfr) from comment #4)
> Can we revert the change for now?

Reverted for now while investigating.
Comment 6 Sergio Villar Senin 2020-06-15 02:22:41 PDT 
(In reply to Peng Liu from comment #2)
> Is FULLSCREEN_API enabled for WebKitGTK? Looks like it is not. Then this
> issue affects Mac version only.

Not by default, but it's implemented. After building with it enabled I cannot reproduce the test case in WebKitGtk either. I'm wondering whether there is some special code in twitter depending on the UA that could cause the issue. Still checking
Comment 7 Sergio Villar Senin 2020-06-15 03:34:57 PDT 
(In reply to Sergio Villar Senin from comment #6)
> (In reply to Peng Liu from comment #2)
> > Is FULLSCREEN_API enabled for WebKitGTK? Looks like it is not. Then this
> > issue affects Mac version only.
> 
> Not by default, but it's implemented. After building with it enabled I
> cannot reproduce the test case in WebKitGtk either. I'm wondering whether
> there is some special code in twitter depending on the UA that could cause
> the issue. Still checking

BTW the issue if any will be with the interaction between RenderFlexibleBox and RenderFullscreen (derived) more than with the FULLSCREEN_API which is different stuff.
Comment 8 Sergio Villar Senin 2020-06-15 06:07:49 PDT 
(In reply to Sergio Villar Senin from comment #7)
> (In reply to Sergio Villar Senin from comment #6)
> > (In reply to Peng Liu from comment #2)
> > > Is FULLSCREEN_API enabled for WebKitGTK? Looks like it is not. Then this
> > > issue affects Mac version only.
> > 
> > Not by default, but it's implemented. After building with it enabled I
> > cannot reproduce the test case in WebKitGtk either. I'm wondering whether
> > there is some special code in twitter depending on the UA that could cause
> > the issue. Still checking
> 
> BTW the issue if any will be with the interaction between RenderFlexibleBox
> and RenderFullscreen (derived) more than with the FULLSCREEN_API which is
> different stuff.

Good news is that I managed to repro it using WebKitGtk so it'll be much easier to get a fix.
Comment 9 Simon Fraser (smfr) 2020-06-15 08:28:28 PDT 
Was reverted in https://trac.webkit.org/changeset/263018/webkit
Comment 10 Sergio Villar Senin 2020-06-18 13:26:10 PDT 
Created attachment 402230 [details]
Patch
Comment 11 Sergio Villar Senin 2020-06-22 05:24:53 PDT 
Created attachment 402464 [details]
Patch

Test working now in Mac/iOS
Comment 12 Sergio Villar Senin 2020-06-23 00:27:36 PDT 
Committed r263389: <https://trac.webkit.org/changeset/263389>
Comment 13 Karl Rackler 2020-06-23 08:38:12 PDT 
Created https://bugs.webkit.org/show_bug.cgi?id=213517 for the test because it is flaky failing since introduction.