1679708 - tab's ui becomes "stuck" if tab is being dragged when tab-modal prompt for HTTP authentication appears

Status: RESOLVED DUPLICATE of bug 1542353

(Toolkit :: General, defect, P2)

Description

[eerroucloi]

Attachment: tab glitch ("test2" tab is overlapping "test3" tab)

tab-modal prompt for HTTP authentication was added in bug 613785

now if a tab is being dragged when that prompt comes up, the tab that was being dragged will become "stuck" part-way between other tabs, resulting in interface visual anomaly as well as e.g. that tab's close button not necessarily working. see attached screen capture.

Comment 1

[Sam Foster [:sfoster] (he/him)]

Can you triage this :pbz

Comment 2

[Paul Zühlcke [:pbz]]

I can reproduce this. This isn't specific to http auth prompts, but any prompt shown via nsIPromptService. I can't reproduce it with just showing a tab dialog (via TabDialogBox).
I was able to reproduce it by running

setTimeout(() => Services.prompt.asyncAlert(gBrowser.selectedBrowser.browsingContext, Services.prompt.MODAL_TYPE_TAB, "Hi", "hello world"), 5000)

and dragging a tab until the prompt opens.

In the browser console I get the following error:

Uncaught TypeError: can't access property "mozItemCount", dt is null

Thrown here: https://searchfox.org/mozilla-central/rev/168c45a7acc44e9904cfd4eebcb9eb080e05699c/browser/base/content/tabbrowser-tabs.js#1861

Gijs, do you have an idea what could cause the tab to become stuck here?

Comment 3

[:Gijs (he/him)]

This is a dupe of bug 1542353, I think?

bug 1544167 and https://bugzilla.mozilla.org/show_bug.cgi?id=1538460#c21 suggest how we could try to solve this.

Comment 4

[Paul Zühlcke [:pbz]]

Thanks! Yes, seems to be the same issue. Same behavior and same error messages in the console.