[Bug] Firefox white flashing with dynamic theme since 4.9.40.

Bug Report

Bug Description

Since the latest update, pages will flash white upon loading. Both foreground and background pages will flash white for a brief moment before the dynamic theme gets applied. This was not an issue before 4.9.40. Static filter continues to work fine.

Website Address

Any website with dynamic mode enabled.

Steps To Reproduce

Open website in foreground:

• Page loads
• White flash occurs
• Dynamic theme is applied

or Open website in background:

• Wait for page to fully load in background
• Upon switch to the loaded tab, white flash occurs
• Dynamic theme is applied

Expected Behavior

Not sure how it worked before the update, but background pages already had the dynamic theme applied when switching to tab.

Pages loaded in the foreground would honor the nglayout.initialpaint.delay configured in Firefox, and the dynamic theme would be applied before the page was shown, thus no white flashing.

System Information

• OS: Windows 10 21H1
• Browser: Firefox 94
• Dark Reader Version: 4.9.40

[racofer]

Hi @bershanskiy and @Gusted , thanks for acting so quickly on this one. I have tested both builds:

• Build 1: same as before, unfortunately. The white flashes occur the same way as with the 4.9.40 release;
• Build 2: this one appears to have fixed the issue. Now I get the same behavior as with 4.9.39;

I will continue testing with Build 2 for the rest of the day and watch for anything odd, but while I could instantly spot the problem with 4.9.40, now with Build 2 I’m yet to notice any white flashes. Thanks!

[racofer]

I will like to give my thought on a possibility that this might be related to the recent released Firefox v94, as @bershanskiy mentions that it doesn’t occur on chromium 🤷🏽 just a possibility to consider.

But version 4.9.39 works fine with Firefox 94, so that is not likely the case.