PM28.5.0: When tab bar is not visible in "normal" mode, it also doesn't show in customize mode

[coffeebreak]

When PM 28.5.0 is set to hide the tab bar when only one tab is open, the tab bar is also getting hidden in "customize mode" when only one tab is open. (If additional tabs are opened, or if the preference is changed, the tab bar is accessible again in customize mode.) In PM 28.4.1, the tab bar was accessible in customize mode regardless of that setting.

Starting with new profile:

• Pale Moon 28.5.0 > Preferences > Tabs > deselect "Always show the tab bar" (browser.tabs.autoHide = true);
• Have only one tab open;
• Open customize mode: the tab bar is not visible there;
• Expected: that although the tab bar was hidden in normal view due to the preference and just one tab open, it would still be accessible in customize mode.

[Moonchild]

This is a corner case that simply isn't taken into account in customize mode. If you need access to the bar you have automatically hidden, just open a second tab (although I'm not sure why you'd need access to it if you are obviously mainly using windowed browsing with the tab bar collapsed -- what are you going to put on it that won't be visible?)

[coffeebreak]

I don't use windowed browsing exclusively, or nearly exclusively.
I'm a light tab user, but use both windowed browsing and windows with multiple tabs about equally.

The use would be to move the "new tab button" (or in theory the "all tabs button") on or off the tab bar.

I noticed what to me is a bug while setting up a fresh portable version.
Because it was new, I was going through the settings available in the UI to make adjustments, in Preferences and Customize, in no special order. I didn't open multiple tabs to do this, there was no reason to.

Typically, I hide the tab bar for only one tab open, and also remove the "New Tabs Button" from the tab bar.
Happens, I went through Preferences first, then Customize.
Intended to remove the new tab button, but (until some problem solving) couldn't because it was not accessible.

This is not how I'd seen Customize behave in the past, and from my perspective some functionality is broken.

This is a corner case that simply isn't taken into account in customize mode.

But this corner case was taken account of through PM 28.4.1, or behaved like it was.

The breakage in Customize is presumably caused by this from v28.5.0 (2019-04-30):
Fixed border drawing when the tab bar is hidden

Can't this work be done in a way that doesn't impair functionality in Customize ?

[Moonchild]

I wasn't aware that this was a regression. I assumed it never worked before.

EDIT: Opened Issue #1072 (UXP) to track this.