1739863 - Firefox loads light theme when starting

Status: RESOLVED INCOMPLETE

(Firefox :: Theme, defect)

Description

[SeedTech]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:96.0) Gecko/20100101 Firefox/96.0

Steps to reproduce:

Close firefox, then reopen it.

Actual results:

Firefox loads the light theme, before then switching to the theme the user has set.
This is just for a about 2 seconds, but this did not happen in 94.

Expected results:

The theme the user had set appears.

Comment 1

[SeedTech]

This also happens when changing themes, if you spam click the change theme button, it is much easier to see.

Comment 2

[BugBot [:suhaib / :marco]]

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

Comment 3

[Simona Badau, Desktop Test Engineering]

I could not reproduce this issue on macOS Big Sur 11.6 on Firefox 95 beta 4 nor the latest Nightly 96.0a1.

To bypass the effects of any extensions and settings, please can you confirm whether you reproduce this issue using Firefox with a new profile?
http://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

Also, could you please give more details about the Appearance of your mac (System Preferences -> General) and the Firefox theme you are using (hit the keys Cmd+Shift+A -> Themes)?

Comment 4

[SeedTech]

(In reply to Simona Badau from comment #3)

I could not reproduce this issue on macOS Big Sur 11.6 on Firefox 95 beta 4 nor the latest Nightly 96.0a1.

To bypass the effects of any extensions and settings, please can you confirm whether you reproduce this issue using Firefox with a new profile?
http://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

Also, could you please give more details about the Appearance of your mac (System Preferences -> General) and the Firefox theme you are using (hit the keys Cmd+Shift+A -> Themes)?

Hey, I have tested and the same thing happens (more noticable when changing themes) in firefox, and firefox nightly. My mac's apprence settings are set to dark, and this applies to any of the built in firefox themes. It just flases to the white theme for a second, but this can be a problem, when being used to dark mode, and then being blinded by light theme. I can record a video of this behaviour if you would like.

Comment 5

[BugBot [:suhaib / :marco]]

The severity field is not set for this bug.
:dao, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 6

[Simona Badau, Desktop Test Engineering]

Tried to reproduce this using the latest Nightly 97.0a1 also on Mac OS 10.15, but with no luck.
SeedTech, when time allows could you please make a recording?

Comment 7

[Simona Badau, Desktop Test Engineering]

Unfortunately, without more information, we can't investigate further or fix this issue. If more information becomes available, we can reopen and look more into this.