1434351 - Unresponsive UI elements in Windows tablet mode

Status: NEW

(Core :: Widget: Win32, defect, P3)

Description

[aleksandar]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:60.0) Gecko/20100101 Firefox/60.0
Build ID: 20180126035135

Steps to reproduce:

Using: Nightly 60.0a1 on Lenovo Yoga 920 on Windows 10. Experienced this in Yoga 510 as well.

I can't find a reliable way to reproduce it, but these steps work in ~30% of the cases:

1. Tilt the screen so that Windows enters the tablet mode with Firefox in the foreground.
2. Try to close some tab near the window control buttons (min, max, exit).

The bug seems to appear randomly in other situations as well, almost always when trying to close a tab.


Actual results:

The entire UI becomes completely unresponsive while Firefox is in focus.

A workaround seems to be to click on any other UI element (for example, swiping on the right side of the screen to show the notification window). After doing so, Firefox becomes responsive again.


Expected results:

The Firefox window should remain responsive.

Comment 1

[aleksandar]

In case there's someone in San Francisco office today or tomorrow (or Mountain View office on Thursday) that would like to see this bug in person, email me with info about how to find your desk and I'll approach you as soon as I reproduce this bug again.

Comment 2

[ovidiu boca[:Ovidiu]]

I tested this on Surface Pro 4 with FF 58 and FF Nightly 60.0a1(2018-01-31) and in my case, I can reproduce a delay when I want to close some tabs, but after a few seconds, the UI becomes responsive. I don't know if this issue is related to the one described by the reporter, but maybe someone with more experience might know.

Comment 3

[Jim Mathies [:jimm]]

I see this as well. I think this is mouse targeting related.

Comment 4

[Mike]

I am experiencing this regularly as well.  It seems most common if I attempt to close a tab by tapping while it is still loading.  The rest of the UI goes unresponsive for an amount of time I haven't yet been able to confirm.  However, I find that over 90% of the time if I switch applications and come back to FF, FF has become responsive again without having to wait any longer.  This may not fix the issue the first time every time, but it is pretty reliable.  Hope this helps.