Affected versions

• 105.0a1(2022-08-11)

Affected platforms

• macOS 11
• Win 11
• Win 10
• Ubuntu 22

Steps to reproduce

1. Launch FF.
2. Go to about:config and activate browser.tabs.firefox-view pref.
3. Restart FF.
4. Go to More Tools-> Customize toolbar in the burger menu.
5. Drag any element after the FF View button and before its separator in the Tab bar.

Expected result

• The FF View separator remains visible.

Actual result

• The FF view separator is no longer displayed.

Regression range

• Not a regression

Additional notes

• The FF View separator remains visible if element is placed before the FF View button.

This is by design - the separator is supposed to be there to separate the tab from the "real" pinned tabs, which isn't necessary if there are other buttons before it.

We could have the separator appear in front of the tabstrip whenever there are any buttons next to it, but that seems unrelated to FxView.

Adding Josh for feedback here as well.

I'd recommend maintaining the separator between toolbar buttons and pinned tabs. Not critical, but I think visual separation between these different elements is a helpful communication tool

https://hg.mozilla.org/mozilla-central/rev/32125b47aa43

Reproduced the initial issue reported using an old Nightly from 2022-08-12, verified that using Firefox 108.0b2 this is no longer an issue across platforms (Windows 10, macOS 11.6 and Ubuntu 22.04).