Bug 193088

Summary:

REGRESSION (Web Animations): CSS Transition sometimes jumps back and forth between initial position and current position

Product:

WebKit

Reporter:

Xidorn Quan <xidorn-webkit>

Component:

Animations

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED DUPLICATE

Severity:

Normal

CC:

bfulgham, dino, emilio, graouts, simon.fraser, webkit-bug-importer, zalan

Priority:

Keywords:

InRadar

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
testcase	none
Test without acceleration	none

Description Xidorn Quan 2019-01-02 13:05:41 PST

Created attachment 358197 [details]
testcase

See the attachment. When you move mouse, there should be a blue block follows the cursor with a delay. However, in Safari Technology Preview, it jumps back and forth if you move mouse continuously.

Gecko has similar bug which I reported in https://bugzilla.mozilla.org/show_bug.cgi?id=1517168 which you may be interested.

Safari 12.0.2 doesn't have this issue, so it seems like a regression between that and the preview version.

Comment 1 Radar WebKit Bug Importer 2019-01-02 14:59:31 PST

<rdar://problem/47011758>

Comment 2 Simon Fraser (smfr) 2019-01-02 15:03:15 PST

Only reproduces with Web Animations enabled.

Comment 3 Antoine Quint 2019-10-28 08:56:40 PDT

This still reproduces with ToT, investigating.

Comment 4 Antoine Quint 2019-10-28 09:08:21 PDT

Adapting the test case to use left/top doesn't reproduce the issue, so this is specific to accelerated animations.

Comment 5 Antoine Quint 2019-10-28 09:09:43 PDT

Created attachment 382075 [details]
Test without acceleration

Comment 6 Antoine Quint 2019-10-28 09:20:06 PDT

While it's more pronounced with Web Animations, the existing behavior with the flag off does exhibit the issue though.

Comment 7 Antoine Quint 2019-11-13 06:25:54 PST

This is a duplicate of https://bugs.webkit.org/show_bug.cgi?id=204116.

*** This bug has been marked as a duplicate of bug 204116 ***