(sorry for the bad bug title, I don't know how to summarize the problem with only a few words)

We got the attached test case in the Firefox support. The page refreshes itself every second - but not if the select field is opened. Then no refresh occurs and the select field stays open. This is the expected behavior and worked without problems until Firefox 124. It still works in Chrome and Safari without problems.

In Firefox 125 and higher it still works when you click somewhere on the select field, but no longer if you click on the arrow of the select field. Then a refresh occurs and the select field closes.

It was reported by a user with Windows 11, I can confirm on macOS 14.4.1. According to mozregression it's a regression from bug 1362907.

This matches what the old display list code used to do:

https://hg.mozilla.org/integration/autoland/rev/a75137d48b99#l6.818

This is a bit tricky to test, because the button isn't really supposed
to be web-observable, but can try to write one...

Can you please assign a severity to this?

The expectation that <select> matches focus when open is bad to break. This only breaks it when hitting the menulist button... Keeping it as S2 even with that tho, for now at least...

Comment on attachment 9398431 [details]
Bug 1893177 - Don't allow menulist button to be hit by mouse. r=#layout

Beta/Release Uplift Approval Request

• User impact if declined: comment 0
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: Yes
• If yes, steps to reproduce: comment 0
• List of other uplifts needed: none
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): One-liner
• String changes made/needed: none
• Is Android affected?: Yes

https://hg.mozilla.org/mozilla-central/rev/9f6047a5887c

Comment on attachment 9398431 [details]
Bug 1893177 - Don't allow menulist button to be hit by mouse. r=#layout

Approved for 126.0b6 and 125.0.3.

I was able to reproduce the issue on an affected Firefox Nightly 127.0a1 build from 2024-04-24, on macOS 12.6.6.
Verified this on Firefox Nightly 127.0a1, build ID 20240425212929 and on Firefox Beta 126.0b6, build ID 20240425210757 (from Treeherder), using macOS 12.6.6, Windows 11 and Ubuntu 22.04.
When loading the attached test case from Comment 0, no refresh occurs and the select field stays open after clicking on the arrow of the field.
However, I have noticed that intermittently, after clicking on the arrow of the field while the page is refreshing, a refresh occurs and the select field closes - see the attached video. It seems that is reproducing with older Firefox versions as well (122.0).
@emilio, do you think this is an issue? If yes, should we reopen this one or file a new bug? Thanks in advance!

If that happened before my patch it's not related to this issue. Feel free to file a new bug specially if it's a regression, but otherwise...

Thanks for the reply, @emilio.
Based on Comment 10 I am marking this verified as fixed on Firefox Nightly 127.0a1, build ID 20240425212929 and on Firefox Beta 126.0b6, build ID 20240425210757 (from Treeherder), using macOS 12.6.6, Windows 11 and Ubuntu 22.04.
I am waiting for the official 125.0.3 RC to verify the fix there too.

Added to the 125.0.3 relnotes.

Fixed an issue that could lead to inconsistent focus handling of <select> elements when opened

Verified as fixed on Firefox 125.0.3 RC, build ID 20240425211020, using macOS 12.6.6, Windows 11 and Ubuntu 22.04, as well.
When loading the attached test case from Comment 0, no refresh occurs and the select field stays open after clicking on the arrow of the field.