Bug 249091

Summary:	[macOS] Flashing for slideshow on https://www.space-invaders.com/world/paris/
Product:	WebKit	Reporter:	Antoine Quint <graouts>
Component:	Animations	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED DUPLICATE
Severity:	Normal	CC:	dino, graouts, simon.fraser
Priority:	P2
Version:	Safari Technology Preview
Hardware:	Unspecified
OS:	Unspecified

Description Antoine Quint 2022-12-11 05:14:15 PST

Steps to reproduce:

1. On macOS, open a full-screen Safari window
2. Load https://www.space-invaders.com/world/paris/
3. Click on the right arrow or press the right arrow key

Notice more often than not a flash. This is likely an animation or compositing bug. Does not seem to happen on iOS at all, and I see it very rarely on iPad.

Reproduces for me on macOS Ventura with system Safari.

Comment 1 Antoine Quint 2022-12-11 05:15:08 PST

There is a CSS transition for the "transform" property on the .slides-control element:

<div class="slides-control" style="position: relative; height: 100%; width: 4536px; left: -1512px; transition-property: all; transition-duration: 0s; transition-timing-function: ease;">

Comment 2 Antoine Quint 2022-12-11 05:23:33 PST

This appears to be resolved in STP 159, going to try to find a clear point when this progressed.

Comment 3 Antoine Quint 2022-12-11 05:40:45 PST

I can track the progression to this range:

https://github.com/WebKit/WebKit/compare/23bb0ec47b1821e3254c6ec68a38b7660042678f...85e031dc15b29db800bff87451782df542bca724

Of all those commits the fix for bug https://bugs.webkit.org/show_bug.cgi?id=244017 seems obviously the most likely to have progressed this. Marking as a dupe.

*** This bug has been marked as a duplicate of bug 244017 ***