[Bug] [Nightly] 2nd+ pinned tabs are shifted down and unclickable

[Fanolian]

Abstract

Though this is a Nightly bug, I file this issue here just for the record and let tst users find the report easier.

On Nightly 2022-10-27 (20221027095047) build, 2nd+ pinned tabs are shifted down and unclickable. This is regressed by Bug 1797011 - Make nsFrameList and AbsoluteFrameList be move-only. There is already a regression bug filed so I did not file a separate bug for TST issue in BMO: Bug 1797703 - fixed positioned elements are broken on several websites.

Steps to reproduce

1. Start Nightly 2022-10-27 with clean profile.
2. Install TST.
3. Pin 2 or more tabs.
4. Press F1 to close and reopen TST tabbar.

Expected result

Pinned tabs align correctly.

Actual result

2nd+ pinned tabs are shifted down and I cannot select them in TST tab bar. Sometimes the bugged pinned tabs may shift back to their intended position after some time. I cannot figure out how though.

Environment

• Platform (OS): Win10
• Version of Firefox: Nightly 2022-10-27 (20221027095047) build
• Version (or revision) of Tree Style Tab: 3.9.7

[happy-dude]

This problem is also manifesting on macOS, albeit in a different manner.

The pinned tabs show up in the Firefox standard tab bar, but TST shows only the first pinned tab. There is no "overflow" on my system.

Firefox nightly details copy-pasted from about:support

Name    Firefox
Version     108.0a1
Build ID    20221027095047
Update Channel  nightly
User Agent  Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:108.0) Gecko/20100101 Firefox/108.0
OS  Darwin 21.6.0 Darwin Kernel Version 21.6.0: Thu Sep 29 20:13:56 PDT 2022; root:xnu-8020.240.7~1/RELEASE_ARM64_T6000

[happy-dude]

This looks like it has been fixed in the latest nightly:

Name: Firefox
Version: 108.0a1
Build ID: 20221028212211
Distribution ID:
Update Channel: nightly
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:108.0) Gecko/20100101 Firefox/108.0

[Fanolian]

Yes.