Affected versions

• Fx77.0b3

Affected platforms

• Windows

Affected platforms

• Have an older version of Fx installed (e.g. Fx71.0b3) and run it at least once (to create a profile).
• Have a high contrast theme enabled on the OS.

Steps to reproduce

1. Launch the latest stub intaller.
2. Change the focus from the 'Update' button.

Expected result

• The Update button should still be visilbe.

Actual result

• Only the label is visible, but not the button border.

Additional notes

• This issue does not occur on Firefox Nightly.
• This issue does not occur on old beta stub installers.
• Issue occurs on both, black and white high contrast themes.
• The issue occurs regardless of the stub installer locale.

The engine is disabling our background and border because that's how high-contrast mode works, but after that it isn't re-applying its default styles, so there is no border or background and the thing just looks like a label instead of a button. Disabling our styling when high-contrast is active should take care of it.

Comment on attachment 9146811 [details]
Bug 1636445 - Skip applying profile refresh button styles in high-contrast. r=agashlin

Beta/Release Uplift Approval Request

• User impact if declined: Stub installer usability issue for users who've configured Windows with a high-contrast theme.
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: Yes
• If yes, steps to reproduce: See comment 0 for STR and other details.

This can't be tested on Nightly because the bug only affects the official branding (that's why it wasn't found until the beta cycle). I've tested in local builds that this patch turns the problem off and makes the button border visible (and also that it doesn't regress the non-high-contrast case), but QA should verify as well.

• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): This is a small, straightforward CSS styling fix.
• String changes made/needed:

https://hg.mozilla.org/mozilla-central/rev/f43b62fdbefc

Comment on attachment 9146811 [details]
Bug 1636445 - Skip applying profile refresh button styles in high-contrast. r=agashlin

Low risk css fix for our installer, approved for the next beta thanks.

https://hg.mozilla.org/releases/mozilla-beta/rev/f2f4bb3f05ec

Verified the fix using the latest beta(Fx77.0b5) on Windows 10, ARM and 8.1.
The update/re-install button from the stub installer is now correctly visible while using the OS high contrast theme.