Description of problem:
Version-Release number of selected component (if applicable):
100% of cases
Steps to Reproduce:
press the winkey (super)
move the mouse cursor to the upper-left corner
All windows of running applications disappear for good.
You cannot switch to them with Alt-Tab, for example
I can observe a grey background, a system panel on top and an application panel on bottom. But clicking on them has no effect. Clicking on "show applications" has no effect either
miniature windows are to be shown. Windows are selectable. Alt-tab should continue working.
This bug lasts at least from Fedora 30.
But it used to be sporadic, not it's always reproducible on my machine
Video card ATI Radeon 9600, video driver: amdgpu.
My previous bug report in Fedora 30
Created attachment 1779131 [details]
an extract from journalctl when the bug occurs
The faulty applications are GNOME Shell (mutter?) and mpv.
GNOME windows disappear because mpv pushes a mangled title
$ wmctrl -l
0x04200002 0 N/A ����������� ���� - mpv
relevant lines in journalctl (see the attached log):
gnome-shell: Invalid UTF-8 string passed to pango_layout_set_text()
gnome-shell: JS ERROR: TypeError: app is null
mpv takes a title from metadata of a video file.
So in my case if I run mpv with the --metadata-codepage=cp1251 option, everything works great: the title is correctly displayed and windows don't disappear.
From this it follows that
1) mpv should validate a string before making it a title
2) mutter should be protected against a mangled string (show an empty title for example)
I filed bug reports upstream