1927414 - Desktop briefly revealed during sidebar animation expansion when double-clicking sidebar toggle button on Linux

Status: NEW

(Firefox :: Sidebar, defect, P3)

Description

[Kestrel]

Attachment: Desktop wallpaper flashes through window during sidebar expansion

STR:

1. Change sidebar.revamp = true on Ubuntu 24.10.
2. Collapse the sidebar if it is already expanded.
3. Double-click the sidebar toggle.

Desktop briefly shows through during expansion animation.

Does not happen when sidebar already expanded or on Windows 11 (opaque window).

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=aa6305a65fb5e7e7a9a1c0b572cdb0e2d4dac4fc&tochange=05fe9b71651f981ada58733864135b940f9c27b0

Regressed by Bug 1915230.

Comment 1

[Sarah Clements [:sclements]]

Emilio, could you take a look at this please?

Comment 2

[Emilio Cobos Álvarez (:emilio)]

To be clear is this only an issue the first time you switch sidebar.revamp = true? I.e. not after a restart or so? If so I don't think this is worth digging into it much...

Comment 3

[Sarah Clements [:sclements]]

(In reply to Emilio Cobos Álvarez (:emilio) from comment #2)

To be clear is this only an issue the first time you switch sidebar.revamp = true? I.e. not after a restart or so? If so I don't think this is worth digging into it much...

I don't think this is the first thing we want users to see if they're in the experiment branch with the new sidebar enabled (even if its fixed with a restart) - I don't think Ania or Yulia would be happy with this. We should try to get this fixed in 133.

Comment 4

[Stuart Colville [:muffinresearch]]

I don't seem to be able to repro this on 24.04.1 in Fx 132 or Nightly.

Bug specifically mentions 132, but does this also occur in Nightly?

Comment 5

[Sarah Clements [:sclements]]

Yeah I missed that. If its not reproducible on 133 beta we can close it out.

Comment 6

[Stuart Colville [:muffinresearch]]

I haven't been able repro on 133 Beta with Ubuntu 24.04.1 so far.

Comment 7

[Sam Foster [:sfoster] (he/him)]

I'm not able to reproduce either. On nightly or 133.0b1 Beta, on Ubuntu 24. I tried with a fresh install, and after restarting and also with a couple of different themes. I tried with both the expand and collapse and show/hide sidebar settings. Is this still an issue for you Kestrel, and if so can you add any more detail to the steps to reproduce?

Comment 8

[Emilio Cobos Álvarez (:emilio)]

Haven't been able to repro in Nightly either.

Comment 9

[Kestrel]

Attachment: Desktop flash when double-clicking sidebar button

It's only a very brief flash during the sidebar animation, most noticeable with a strongly contrasting background. It is easier to reproduce with software webrender (layers.acceleration.disable = true).

I see it with HW-WR and SW-WR, Wayland and XWayland, Ubuntu 24.04.1 LTS and Ubuntu 24.10, Beta 133.0b1 and latest Nightly 134.0a1 (2024-10-29).

Comment 10

[Sarah Clements [:sclements]]

(In reply to Kestrel from comment #9)

Created attachment 9434172 [details]
Desktop flash when double-clicking sidebar button

It's only a very brief flash during the sidebar animation, most noticeable with a strongly contrasting background. It is easier to reproduce with software webrender (layers.acceleration.disable = true).

I see it with HW-WR and SW-WR, Wayland and XWayland, Ubuntu 24.04.1 LTS and Ubuntu 24.10, Beta 133.0b1 and latest Nightly 134.0a1 (2024-10-29).

Is that video with layers.acceleration.disable = true? Because if its barely perceptible with that pref in its default setting then this is not worth spending time on (also with 3 other people confirming they can't reproduce).

Comment 11

[Kestrel]

The screen capture video is not a 1:1 representation since it has a limited frame rate. The length of the flash seems to be dependent on hardware capabilities and available resources. Note that older hardware can have acceleration disabled by default.

Comment 12

[Sarah Clements [:sclements]]

Emilio, should we 'wont't fix' this or move it to some sort of layout component with a P3 or lower?

Comment 13

[Emilio Cobos Álvarez (:emilio)]

I think it's probably worth keeping here, since the bug might be / probably is in the sidebar animation code. But yeah given this is both rather hard to repro and it needs a double click (which is not a thing you'd usually do with that button anyways) I think the current severity / priority is fair...