Bug 168231 – REGRESSION(r211967): [GTK] Glitch rendering backgrounds after hovering elements in HiDPI

• Status: RESOLVED
• Resolution: FIXED
• Component: WebKitGTK

[Adrian Perez]

Created attachment 301346 [details]
Screen capture demoing the issue (GIF, ~4 MiB)

In some websites, after hovering an element which changes the background, the original
background is not correctly restored when the element is not hovered anymore. Check the
attached GIF for a demo of how this looks when the issue is triggered by PhpReport
(https://github.com/Igalia/phpreport).

This happens both an AC and non-AC modes, but only in HiDPI: manually setting the
window scale factor to 1x in GNOME Tweak Tool makes the glitches go away.

[Adrian Perez]

Created attachment 301347 [details]
Even more background glitches in AC mode (without needing to hover-unhover)

Moreover, when AC is enabled, there are additional background rendering
glitches which show already as soon as the page loads, without needing
to hover/unhover elements. It looks like those glitches could be related.

[Adrian Perez]

These are happening at least since WebKitGTK+ 2.14.4, and they also happen
in the current Git “master” with MiniBrowser.

[Adrian Perez]

Carlos García suggested reverting r211967 (http://trac.webkit.org/changeset/211967).
Doing that makes all the glitches go away (both in AC and non-AC modes). Adding Miguel
Gómez (the author of r211967) in the loop as well, hoping that he can take a look at
this.

[Miguel Gomez]

We've decided to rollback r211967 and work a better solution for the scrolling problem. Due to that this is not reproducible anymore, so closing.