1898619 - Firefox incorrectly jumps to anchor with "reduced motion" enabled on MacOS

Status: NEW

(Core :: Panning and Zooming, defect, P3)

Description

[Claas Augner [:claas]]

1. In Mac OS, enabled "Reduced motion" (System settings > Display > Accessibility > Reduced motion).
2. Go to https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-reduced-motion
3. Click an entry in the TOC on the right (e.g. "User preferences").
4. Expected: "User preferences" header to be below top navigation.
5. Actual: "User preferences" header hidden by top navigation.

Note: Clicking the same entry again scrolls to the right position.

Comment 1

[Claas Augner [:claas]]

Important to note that we use scroll-margin-top to prevent the header to appear behind the top navigation, but this seems to be ignored here.

Comment 2

[Alice0775 White]

I can reproduce the issue on Nightly128.0a1 Windows11 but not on Chrome.
Interestingly, when the bug occurs, if you click the link again, the page scrolls to the correct position.

Comment 3

[6k64x4ma]

see also: bug 1816003