Persistent crash on playback
Description of bug:
Starting playback frequently causes MuseScore to crash.
This bug appears randomly and cannot be reliably reproduced. Sometimes it occurs when I start playback immediately after opening a score. More often, it occurs when I start playback after making a change. The type of change doesn't matter; it can be adding or subtracting note, inserting or deleting dynamics, or altering some feature of the layout, e.g. changing the curve of a slur.
I have noticed that saving after every change, no matter how trivial the alteration, seems to keep MuseScore from crashing as often, but the strategy is not reliable.
I am not able to run MuseScore in debugging mode because it crashes immediately upon opening a score with
time 0.000000 not found in RepeatList
Aborted (core dumped)
I'm attaching the output from /var/log/kern.log, which shows MuseScore segfaulting during calls to libstdc++. The quantity of segfaults is an indicator of how frequently the problem occurs.
I'm also attaching a sample score in progress that exhibits the bug. The playback will sound awful since I use LinuxSampler rather than MuseScore's internal synthesizer. Also note that this is an .mxcz copy of the .mscx file I actually work on.
Intel quad core, 2.67 GHz, 64 bit architecture
3.9 gig RAM
Kubuntu 16.04 with KXStudio repo enabled
4.4.0-101-low-latency Linux kernel
KDE Plasma desktop 5.5.5
jackd 0.124.2, started with Cadence