Crash on change sound for channel added via instrument change

• Nov 20, 2018 - 19:27
Reported version
3.0
Priority
P0 - Critical
Type
Functional
Frequency
Once
Severity
S2 - Critical
Reproducibility
Always
Status
closed
Regression
Yes
Workaround
No
Project
MuseScore

1) default empty score
2) add an instrument change text from the palette somewhere within the score
3) open mixer
4) open the piano column to show both channels
5) select the second (new) channel
6) change sound using details dropdown

Result: crash, in Channel::firePropertyChanged

Comments

• Nov 21, 2018 - 08:34

What do you mean by details dropdown? Changing patch for the new channel doesn't produce a crash for me as well as changing other properties regarding that channel.

Reply

• Nov 21, 2018 - 15:40

It is indeed a bit finicky to reproduce. I do mean the Patch. For me it's reproducible every time if I follow those steps precisely, bit crash does go away if I get creative and doing other things in there somewhere, like moving a slider. I guess it is a memory management issuI and hence symptoms can appear aottle random?

Reply

• Nov 22, 2018 - 14:10
Status PR created ⇒ active

Above fix is invalid. This one should work:
https://github.com/musescore/MuseScore/pull/4198

I believe this is happening due to listeners not being detached when objects are deleted. I'm using the Qt system now for maintaining listeners, so this will hopefully be more robust. It is tricky, though, to mix Qt with non-Qt code.

Also, I was getting this issue sometimes with moving the volume sliders. This is more an unstable UI issue than something specific to patches.

Reply