1742976 - Text and color of tab breaks when (re)loading a site

Status: UNCONFIRMED

(Core :: Graphics, defect)

Description

[github-mg]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:94.0) Gecko/20100101 Firefox/94.0

Steps to reproduce:

I opened the latest Firefox Nightly 96.0a1 (2021-11-24) (64-Bit) on Windows 10 and opened a few websites in different tabs.

Actual results:

After Firefox has finished loading bugzilla.mozilla.org, the color of the text of all other tabs (not the current one) are flashing (see 0:25s, 0:40s-0:55s) and the light grey background color of the current opened tab disappears (see 0:27-0:31s, 1:05s and 1:42s). It is only visible when hovering over that tab again. After some time the light grey background color of the current tab stays visible (see 0:32s) even after moving the mouse cursor out of it (as it should)

Another very common glitch I saw is the one where only a part of the background color of the current tab is gone (see 1:21s) or when the text of a tab is completely gone or 'just' corrupted (see 1:46s)

Expected results:

The current opened tab should always have a light grey background color, without being destroyed and the text should not get currupted by reloading a tab.

Comment 1

[github-mg]

Attachment: firefox-bug-4.mp4

This is the video of the glitches I described in the bug report. I've been seeing this glitches for a few days now, but this is the first time I saw so many at once.

Comment 2

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

The Bugbug bot thinks this bug should belong to the 'Firefox::Tabbed Browser' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 3

[Clara Guerrero ( Need Info Brindusa Tot Please)]

Hi there,
Thanks for you report.
Can you please attach your about:support information? You started noticing these glitches on Firefox Nightly 96.0a1, but not on previous ones, correct?
If you enter safe mode, can you still experience those glitches?
Best,
Clara

Comment 4

[Andrew Osmond [:aosmond] (he/him)]

Also, if this is a recent change for you on nightly, could you please run mozregression if possible to try and identify the root cause? Thanks!

https://mozilla.github.io/mozregression/quickstart.html

Comment 5

[github-mg]

Attachment: about:support

Comment 6

[github-mg]

(In reply to Andrew Osmond [:aosmond] (he/him) from comment #4)

Also, if this is a recent change for you on nightly, could you please run mozregression if possible to try and identify the root cause? Thanks!

https://mozilla.github.io/mozregression/quickstart.html

I was able to reproduce this glitch in Firefox 94.0.2 (64-Bit), however, there were not as many glitches as I could record in the video above. And I was also seeing it after enabling the safe mode (with deabled addons and themes) in the latest Nightly version.

Should I still try using mozregression, even though this is only about two or three weeks old?

Comment 7

[github-mg]

I downloaded mozregression and followed the instruction on the website you gave me. I ran it two times (the first with specifying the date, the second with specifiying the release) and it gave me the following two commits as a result:

The first time:

2021-12-03T17:29:40.258000: DEBUG : Found commit message:
Bug 1728727 - Remove unused code in TabListener. r=kashav

Differential Revision: https://phabricator.services.mozilla.com/D124316

2021-12-03T17:29:40.258000: DEBUG : Did not find a branch, checking all integration branches
2021-12-03T17:29:40.258000: INFO : The bisection is done.
2021-12-03T17:29:40.258000: INFO : Stopped

And the second time:

2021-12-03T17:42:00.279000: DEBUG : Found commit message:
Bug 1729241 - Pt 3 - Make spatial node indices an opaque type r=gfx-reviewers,kvark

Since spatial node indices will become opaque handles in future,
remove the last part of code outside spatial_tree that relies
on the index. In this case, switch the hit-testing code to use
the spatial node indices as a hash key. This is unlikely to have
any noticeable performance impact since hit-tests are relatively
rare, and generally only access a small number of spatial nodes.

Differential Revision: https://phabricator.services.mozilla.com/D124706

2021-12-03T17:42:00.279000: DEBUG : Did not find a branch, checking all integration branches
2021-12-03T17:42:00.279000: INFO : The bisection is done.
2021-12-03T17:42:00.279000: INFO : Stopped

For me, exspecially the first commit sounds interesting, because it has something to do with "tabs" (but I think you now better what is important)

Comment 8

[Andrew Osmond [:aosmond] (he/him)]

Bug 1729241 sounds more likely to me.

Comment 9

[Glenn Watson [:gw]]

It looks like from the about:support that this was gathered in safe mode (which I think is why software webrender is enabled).

A couple of questions:

• Do the same glitches occur in safe mode vs. normal mode?
• Could you post your about:support when safe mode is not active (so we can see what GPU/driver is active and that hardware webrender is being enabled).

Comment 10

[github-mg]

Attachment: about:support-not-in-safe-mode

Although I encountered these glitches in safe mode in the Nightly 96.0a1 (2021-11-24) (64-Bit), I just tried it again (Nightly now updated itself to 97.0a1 (2021-12-07) (64-Bit)) and I can still see them, but **not in safe mode**.