1754950 - [Wayland] Pop up menus are flashing/flickering when opened/resized

Status: VERIFIED FIXED

(Core :: Widget: Gtk, defect, P3)

Description

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Attachment: flash.gif

Affected versions

• 99.0a1
• 98.0b3
• 97.0 (if Wayland ENV enabled)
• 91.6.0esr (if Wayland ENV enabled)

Affected platforms

• Ubuntu 21.04

Steps to reproduce

1. Open Firefox and Protection menu.
2. Expand and narrow the protection menu.

Expected result

• No visual glitches.

Actual result

• Protection menu is flashing. This can be seen when opening Pocket and the downloads menu as well.

Regression range

• First regression range with default settings takes me to bug 1749174. Forcing Wayland gives this pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=8f68705097b4bf88cd61b43b14401cde98ac75b6&tochange=6c10970490f3cc19e644964f583be1a047c08b2c. I believe that bug 1637948 may be the cause but this is only an assumption. Older builds with enabled Wayland have tab crashes on Ubuntu 21 and I tried to reproduce the issue on the View history saved bookmarks and more-> History/ Bookmarks/ Downloads panel but the issue is really intermittent so the regression range may be inaccurate or it may be not a regression.

Notes

• Screen Recording attached.
• Reproduced on two VM stations with Ubuntu 21 while having Wayland inside about:support-> Protocol Window. Cannot reproduce with xWaylan on Protocol Window. I don’t know if this reproduces on native installed ubuntu 21 as well.
• 97.0 and 91.6.0esr are affected as well if opened with Wayland ENV enabled.

Comment 1

[Martin Stránský [:stransky] (ni? me)]

Do you see the flashing with permission/addon popups only?

Comment 2

[Martin Stránský [:stransky] (ni? me)]

Please run Firefox on terminal with MOZ_LOG="WidgetPopup:5", reproduce the flashing once and attach the log here.
Thanks.

Comment 3

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Attachment: flash_02.gif

(In reply to Martin Stránský [:stransky] (ni? me) from comment #1)

Do you see the flashing with permission/addon popups only?

I can see this on the Downloads Panel and Library panel as well.

(In reply to Martin Stránský [:stransky] (ni? me) from comment #2)

Please run Firefox on terminal with MOZ_LOG="WidgetPopup:5", reproduce the flashing once and attach the log here.
Thanks.

I will run this and come back with the details.

Comment 4

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Attachment: Library-_ Bookmarks.log.txt.moz_log

I hope this helps. This was reproduced inside Library-> Bookmarks panel. I tried making another one on the Protection pop up but after the restart, for some reason, the logs are no longer exported. If there is another log needed please let me know.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

:atrif, since this bug is a regression, could you fill (if possible) the regressed_by field?
For more information, please visit auto_nag documentation.

Comment 6

[Martin Stránský [:stransky] (ni? me)]

Yes, that's because we use move-to-rect to position that window. Just for the check, please go to about:config, add 'widget.use-move-to-rect' boolean key, set it to false and restart browser. You should not see that flickering then.
As a workaround we may use move-to-rect only if popup window is outside of main browser window.

Comment 7

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Attachment: 1754950.gif

(In reply to Martin Stránský [:stransky] (ni? me) from comment #6)

Yes, that's because we use move-to-rect to position that window. Just for the check, please go to about:config, add 'widget.use-move-to-rect' boolean key, set it to false and restart browser. You should not see that flickering then.
As a workaround we may use move-to-rect only if popup window is outside of main browser window.

Hello! Unfortunately, I can still see the flicker on Ubuntu 21.1 VM with Firefox 98.0b5 after setting the above pref as described. Please see the attached screen recording.

Clearing ni? because I don't know for sure if the regression range is accurate.

Comment 8

[Martin Stránský [:stransky] (ni? me)]

Yes, it's caused by repeated resize of the popup and workaround for move-to-rect where window needs to be hidden to reposition/resize it.

Comment 9

[Martin Stránský [:stransky] (ni? me)]

We have only few options how to handle it due to a bug in Wayland/Gtk: https://gitlab.gnome.org/GNOME/gtk/-/issues/1986 which is fixed in Gtk4.

There's a new xdg-popup 'reposition' interface for it:
https://lists.freedesktop.org/archives/wayland-devel/2019-October/040968.html

Comment 10

[Martin Stránský [:stransky] (ni? me)]

For most cases it's fixed by Bug 1760276.

Comment 11

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Attachment: ubuntu_flash_2.gif

Hello Martin!
I looked over this today and the initial issue seems to be gone on Ubuntu 21.04 using Firefox 100.0b7 (20220417185951) with Wayland. I can no longer see the flashing on the Libray/ Downloads and Enhanced Tracking Protection dropdowns.

However, there is a slight flash when expanding/ collapsing the Enhanced Tracking Protection dropdown. I attached a screen recording. This also seems to be intermittent and it's not as obvious as before. I cannot reproduce it on xwayland window protocol.

Should we close this issue as verified and open another one for the remaining issue? Thank you!

Comment 12

[Martin Stránský [:stransky] (ni? me)]

The fix here works only when popup window is inside main Firefox window - in such case we expect it's also visible on screen so we don't use move-to-rect popup placement which involves the flashing during popup resize.

So this is expected behavior and covers 99% user cases I guess.

Comment 13

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Thank you, Martin! Closing this per comment 11 and comment 12.