1954821 - Ghost tabs that cannot be close, selected, or moved

Status: RESOLVED FIXED

(Firefox :: Tabbed Browser, defect, P1)

Description

[Francesco Lodolo [:flod]]

Attachment: Tab screenshot

I've been seeing this on Nightly for a few days, still not sure how I get there. In this case, it happened with a container tab, but in other cases it was standard ones.

Suddenly, one of the tabs doesn't close. Clicking on it doesn't open the page, there is nothing in console.
Moving it around creates even more chaos (the screenshot is taken after trying to drag an Instagram tab past the Bugzilla tab).

The only way to fix the tab strip is to restart the browser.

Comment 1

[Mike Conley (:mconley) (:⚙️)]

This might be a dupe of bug 1952530.

Comment 2

[Francesco Lodolo [:flod]]

Attachment: tab_strip.html

Tried to capture the tab strip at the moment of filing the bug. Hopefully I didn't leave any PII in there.

As mentioned, the console doesn't show any error when I try to click around.

Comment 3

[Francesco Lodolo [:flod]]

Interestingly enough, it happened again after a restart. I was able to close the tab from the dropdown list at the bottom of the tab strip, but it didn't disappear from that list.

Comment 4

[Mike Conley (:mconley) (:⚙️)]

Do you have STR that lets you reliably reproduce the bug in a new profile?

Comment 5

[Francesco Lodolo [:flod]]

(In reply to Mike Conley (:mconley) (:⚙️) from comment #4)

Do you have STR that lets you reliably reproduce the bug in a new profile?

Sadly, no. I've been trying to find one for the past week.

Comment 6

[Andrew McCreight [:mccr8]]

I've also been seeing this. Very rarely, maybe every 3 days. I don't have any STR unfortunately. I think it is happening the most in my tab that I have 18 pinned tabs. I think it often happens when I have a ton of tabs open additionally.

Comment 7

[Francesco Lodolo [:flod]]

Not sure if bug 1954865 is a variation of this one, as I can't reproduce this consistently, and for me it happens with any tab, not just New Tab.

Comment 8

[Stephen Thompson [:sthompson]]

In Francesco's tab strip DOM, the Instagram <tab> has style="transform: translateX(450px);", which is most likely what's set on most tabs during a drag operation. https://searchfox.org/mozilla-central/source/browser/components/tabbrowser/content/tabs.js#2383-2389 When the drag operation ends, that transform style is supposed to be cleared from all tabs and tab group labels here https://searchfox.org/mozilla-central/source/browser/components/tabbrowser/content/tabs.js#2744-2749

It's odd to have just one tab left with this style attribute. I can understand how getting into this situation would be fixed by restarting the browser. I would also expect that starting a new drag operation would fix this by recomputing all of the tabs' style transforms, so there is probably more going on than just the style attr. So far, that's the only anomalous thing I can see.

Comment 9

[Stephen Thompson [:sthompson]]

This was likely fixed by an intervening patch, but I am not sure which exact one it would be.