Affected versions

• Firefox 101.0a1
• Firefox 100.0b2
• Firefox 99.0

Affected platforms

• Windows 8.1 x64
• Windows 10 x64
• Ubuntu 20 x64
• macOS 12

Steps to reproduce

1. Set White High contrast on system level.
2. Open Firefox and go to the about:preferences page at the Search Shortcuts section.
3. Double click on keyword input field from any search engine in order to add a keyword.

Expected result

• Editing the input field you should not see any extra white line before the textbox.

Actual result

• See extra white line before the edited input field.

Regression range

• I will come back with regression range ASAP.

Additional notes

• Minimize and maximize the browser window (change the window width) you will see
  what's under the edited input field (see bug: 1192474)

I've user mozregression to determine a regressor:

2022-04-27T14:30:29.362000: DEBUG : Found commit message:
Bug 1755184 - Remove macOS-specific --focus-ring-box-shadow. r=Itiel
Differential Revision: https://phabricator.services.mozilla.com/D138624
2022-04-27T14:30:29.362000: DEBUG : Did not find a branch, checking all integration branches
2022-04-27T14:30:29.364000: INFO : The bisection is done.
2022-04-27T14:30:29.366000: INFO : Stopped

The investigation was made in Windows 10.

:dao, since you are the author of the regressor, bug 1755184, could you take a look?
For more information, please visit auto_nag documentation.

Set release status flags based on info from the regressing bug 1755184