1637294 - Tab key selector has white dotted lines instead of black dotted lines

Status: RESOLVED WONTFIX

(Firefox :: Installer, defect)

Description

[Daniel Cicas [:dcicas], Release QA]

Attachment: image.png

Affected versions

• Fx 77.0b4

Affected platforms

• Win 7 x64
  Win 10 x64
  Win 10 aarch 64

Steps to reproduce

1. Download the Stub Installer and run it.
2. Click "Yes" on the UAC Prompt.
3. Open Firefox at least once so that a profile gets created.
4. Uninstall the installed Firefox copy.
5. Run Stub Installer again.
6. Press Tab key.

Expected result

• The Tab selector should be black dotted lines.

Actual result

• The Tab selector is a white dotted line.

Regression range
Will return with a regression range ASAP.

Comment 1

[Molly Howell (she/her) [:mhowell]]

I've been examining this by playing with the background color on the button, and it looks to me like the browser engine is selecting between the two focus rectangle styles (small black dots vs. large white dots) based on which one would provide more contrast against the button's background. If the background isn't changed from the default, the black dots are always used, but they are also used if the background color is customized to white or a light gray. But if the background color is darker, like a darker grey (the cutoff appears to be somewhere around #bbb), or our custom blue, you start getting this larger, white dot pattern instead. Somehow the display scale factor can also affect this behavior, perhaps just by changing relative sizes of different elements, so it seems like there's some fairly complex logic driving this behavior, and I know I haven't fully characterized it.

So, my opinion on this issue is that a) the behavior described is an intentional feature of the web engine we're using, and b) the behavior is there for a good reason (improving visual contrast) and we should leave it alone.