1922592 - Dragging a tab (for drag-and-drop) randomly fails as of Firefox 131, possibly confused by the new tooltips / hover preview

Status: UNCONFIRMED

(Firefox :: Tabbed Browser, defect)

Description

[Vincent Lefevre]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:131.0) Gecko/20100101 Firefox/131.0

Steps to reproduce:

1. Open Firefox 131 with tabs in a window.
2. Put the mouse pointer over a tab.
3. Once the tooltip (tab title + host) appears (which is almost immediate), try to drag the tab.

Actual results:

Sometimes, nothing happens, as if Firefox did not notice that the left button was pressed. Sometimes, same issue, except that a black rectangle appears. It seems that this black rectangle has about the same dimensions as the preview when a preview appears (I sometimes get a preview, but this is not always the case and I don't know why).

Expected results:

The tab should be dragged.

Note: When the issue occurs, a solution that always seems to work is to drag the tab before the tooltip appears, but this is rather difficult as one needs to be fast.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Firefox::Tabbed Browser' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Vincent Lefevre]

And sometimes, it is possible to drag a tab, but only in the same tab bar (in particular, not to a tab bar of another Firefox window),

Comment 3

[Vincent Lefevre]

Actually it seems that one can move a tab only toward the right (but this does not work if one tries to move it toward the left first). After the initial move, there does not seem to be any restriction. So, in short, if one wants to move a tab leftward, one first needs to move it a bit toward the right, then backward to the left.

But this does not work for the rightmost tab. So, for this case, one first needs to move the tab at its left to the rightmost position.

Comment 4

[Vincent Lefevre]

(In reply to Vincent Lefevre from comment #3)

But this does not work for the rightmost tab. So, for this case, one first needs to move the tab at its left to the rightmost position.

Well, dragging the rightmost tab seems to work if done when the tooltip is not present, i.e. either before it appears (one needs to be quick enough) or by making it disappear with the Esc key.

I'm not sure, though, because after some time, it seems that the issue no longer appears for a while. There seems to be randomness in the behavior.

Comment 5

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:mconley, could you have a look please?

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