Gala: Grey backdrop after switching workspace via gestures

[hanaral]

@JoseExposito I think that you said you were never able to reproduce it

What Happened

Using the workspace gestures by lightly swiping in opposing directions in quick succession causes the background to be replaced by the system grey backdrop (it doesn't actually switch workspace).

Expected Behavior

Workspace switching should not create such bugs.

Steps to Reproduce

1. Swipe to another workspace quickly, with only enough contact with the fingers to just about toggle the animation
2. Do it again in the other direction
3. Repeat until you see the bug

Video for referance:

https://user-images.githubusercontent.com/58219504/103150631-f1488080-476d-11eb-8e0a-0a0737095c5c.mp4

Logs

Utterly useless:

Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
 Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
  Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
 Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.
Window manager warning: META_CURRENT_TIME used to choose focus window; focus window may not be correct.

Platform Information

elementary OS 6 Daily, Gala compiled from latest git

[hanaral]

@JoseExposito I've made a demonstation video on how you should be able to reproduce it on a touchpad:

https://user-images.githubusercontent.com/58219504/103486723-c60e0300-4df7-11eb-90c8-82a56b643344.mp4

[JoseExposito]

Great! Thanks for the video @hanaral :tada: Now I know what is going on. I was trying something different.
I found the bug, but I don't know how to solve it yet. I'll ask for help in the Gala channel as soon as Slack is back online.

[JoseExposito]

It should be fixed here @hanaral , in case you can confirm it: https://github.com/elementary/gala/pull/1024/files

[hanaral]

@JoseExposito Yup, can't reproduce it. Good job dude!
As a side note, when testing for #1016 I managed to reproduce the dreaded wallpaper-drawn-over-the-desktop bug, I still have no clue how I reproduced it but it might be a good idea to keep an eye out