start plasma session, open dolphin, select some file/folder, press shift+del, cancel file/folder deletion, right click sound icon in the system tray,
select "Configure audio volume...", click "Audio volume" section,
click "applications" tab, click the button to mute/unmute
the notification sounds (above percentage).
Result: mute/unmute button changes visually but the state of the "Notification sounds" feature remains the same.
Click "Notification sounds" slider, click mute-unmute button again: now the button works as expected.
*** Bug 395293 has been marked as a duplicate of this bug. ***
Git commit fbdef07f554bbec59d6142837fdf44afd103f6dc by Kai Uwe Broulik.
Committed on 11/04/2019 at 07:27.
Pushed by broulik into branch 'Plasma/5.15'.
[StreamRestore] Don't mess with channels
Just set volume for all of them.
Otherwise when just calling setMuted, we will send the original volume struct, which might have multiple channels,
with a hardcoded channel map that only has one channel. PulseAudio then refuses to write the settings.
Patch ported from pulseaudio-qt
Differential Revision: https://phabricator.kde.org/D20450
M +4 -4 src/streamrestore.cpp