1600025 - Cannot very rapidly close all tabs via middle click

Status: NEW

(Firefox :: Tabbed Browser, enhancement, P3)

Description

[Dmitriy]

Steps to reproduce the problem:

1. Create 4 new tabs.
2. Very rapidly middle click 4 times on new tab #1, near its left edge (without moving the mouse)

What is the expected behavior?
All 4 new tabs are gone, all were closed.

What went wrong?
1 or 2 tabs remain open.

If I set toolkit.cosmeticAnimations.enabled to False in about:config, this problem disappears. But I shouldn't have to do that, I don't actually want to disable animation.

This problem is caused by subsequent middle click being applied to the tab that is already being animated as closing, so that click is wasted. It can easily be proven: in step 2 click near tab's right edge - all 4 tabs will be closed. In other words, problem is caused by tab from the right not having enough time to get under mouse pointer because of animation, so subsequent middle click gets applied to the tab that is already closing anyway, thus it does nothing.

Probably something like that could be a solution:
If middle clicked tab is already being closed, immediately finish its "closing animation", and propagate "close this tab" command to the tab to the right from it. Check if it is already being closed, and so on...

In case it might be helpful, I reported the same problem to Chrome's developers a year ago, they have already fixed it: https://bugs.chromium.org/p/chromium/issues/detail?id=920902
Chrome's UI designer described that this is how (without this problem) tabstrip should behave in 2010 already: https://bugs.chromium.org/p/chromium/issues/detail?id=44782