Found in

Firefox 105.0a1

Affected versions

104.0a1
105.0a1

Affected platforms

Windows 10
Ubuntu 20

Preconditions

In about:config set:
"browser.theme.colorway-closet" to true
"browser.tabs.firefox-view" to true

Steps to reproduce

1. Open Colorways modal from Fxview or from about:addons
2. Using the keyboard, get any random colorway in focus, keep left or right keyboard arrow for 2-3 seconds and release it.

Expected result

The colorway in focus is not applied.

Actual result

The colorway selected should be applied accordingly.

Regression range

Not a regression.

Note:

The issue seems to be intermittent, I can reproduce it around 2-3 attempts from 5. It is not reproducible at all on macOS.

Some observations while reproducing this bug on Windows 10: the failure occurs when we try to read an extension ID because extension is null. We pass data about the colorway here, which is especially obtained via getData (call, definition). getData is returning null however, causing the error and failing to load a colorway.

When a theme is enabled and then disabled (or vice-versa) really quickly, there is a chance that the theme will fail to load due to a race condition. To address this issue on the colorway closet modal, delay keyboard arrow input on colorway family or intensity radio buttons - this will give the browser time to fully load a selected colorway before trying to view and enable another one.

Can this be resolved wontfix/invalid Amy? I don't think the interaction described will be possible anymore, right?