Tested in 97.0 release on Windows 7.

STR:

1. Flip widget.non-native-theme.enabled to false.
2. Open about:preferences to confirm the current scrollbar style.

Expected Behavior:

Firefox uses Windows 7 scrollbars on Windows 7 when widget.non-native-theme.enabled to false (see FF96).

Actual Behavior:

Firefox uses Windows 10 scrollbars on Windows 7 even though widget.non-native-theme.enabled to false.

Presumably this was regressed by bug 1747618 comment #7? I understand the security/fingerprinting concerns but (for the lack of a better word) Windows 10 scrollbars look just awful on Windows 7, and judging from some other bug tickets it would seem like win32k lockdown won't be fully supported on Windows 7 anyway? Personally, I Would really appreciate if Mozilla can provide some sort of workaround to reverting to Windows 7 scollbars, and only remove this from the stable version after Firefox's windows 7 support moves to ESR only.

I did check out widget.non-native-theme.scrollbar.style but I didn't see a "Windows 7 Aero/Classic scrollbar" option there.

The Bugbug bot thinks this bug should belong to the 'Core::Widget' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Set release status flags based on info from the regressing bug 1747618

Yeah we always use the non-native theme scrollbars now, and we're probably not going to change this. Before those patches you'd get some scrollbar styles in the parent process and others in the child process, and since then the native scrollbars drawing code has been removed in
https://hg.mozilla.org/mozilla-central/rev/971c7211949d886f0ff4fa11f2d5189700084373.

I'm not sure about the Win32k lockdown state for Win7, but disabling the non-native theme is not the right way to fix this as the native theme can cause other compat issues due to form control rendering.

The right way to fix this would be to add a non-native Win7 scrollbar style like Win11 has. I'd be happy to review a patch but it's most likely not a priority to fix.

I was so happy to finally get Firefox to look like just what I wanted, only to see the cool look getting destroyed yet again. Code changes like this should be toggleable if they are there by default; you can't assume the user will only have one of 5 styles that Microsoft wants people to use.

Resolving this bug as WONTFIX because Firefox versions >= 116 no longer support Windows 7-8.1.