Bug 204951 – compositing/video/video-border-radius-clipping.html is a flaky Image Failure

• Status: RESOLVED
• Resolution: FIXED
• Component: Compositing

[Matt Lewis]

compositing/video/video-border-radius-clipping.html is a flaky Image Failure on Catalina Release WK2

This seems to have first started after https://trac.webkit.org/changeset/252245/webkit where Angle support was introduced.

https://build.webkit.org/results/Apple-Catalina-Release-WK2-Tests/r253206%20(1314)/results.html
https://results.webkit.org/?suite=layout-tests&test=compositing%2Fvideo%2Fvideo-border-radius-clipping.html
https://build.webkit.org/results/Apple-Catalina-Release-WK2-Tests/r253206%20(1314)/compositing/video/video-border-radius-clipping-diffs.html

[Radar WebKit Bug Importer]

<rdar://problem/57703078>

[Alexey Proskuryakov]

This is quite interesting.

The first failure on results.webkit.org is indeed with r252246, but that seems very unlikely to be related, and the failure is too rare to blame to a specific revision.

But the test also fails on other queues, both or results.webkit.org and internally. It fails in many different ways. The failure that Matt pointed out is painting a red rectangle. Other failures include antialiasing differences and getting a red line.

[Simon Fraser (smfr)]

Created attachment 385210 [details]
Patch

[Simon Fraser (smfr)]

https://trac.webkit.org/changeset/253310/webkit

[Truitt Savell]

This appears to have caused compositing/video/video-border-radius-clipping.html to become a constant failure on High Sierra and Catalina wk1

history:
https://results.webkit.org/?suite=layout-tests&test=compositing%2Fvideo%2Fvideo-border-radius-clipping.html

Diff:
https://build.webkit.org/results/Apple%20High%20Sierra%20Release%20WK1%20(Tests)/r253485%20(17701)/compositing/video/video-border-radius-clipping-diffs.html

Looks like a single pixel difference.

[Truitt Savell]

Tracking this in https://bugs.webkit.org/show_bug.cgi?id=205226