File opencpn.conf 'leaks' to 0 byte !

[nohal]

Originally Posted by Didier B

I am not sure the button has any responsibility in this issue, as :

1. I have observed the problem before using the pi desktop ;
2. It upraised again yesterday, though I had formerly halted Opencpn with a CTRL+Q, before shutting down the rpi ...

Your system is pretty clearly not syncyng the data to the filesystem and there is nothing OpenCPN can do about it. It is impossible that it did not close and save the config file and has written that the shutdown was complete to the logfile at the same time, simple order of execution.
If you want to make it better, start it using a shell script with this content:

#!/usr/bin/env sh

/usr/bin/opencpn

sync
echo 3 > /proc/sys/vm/drop_caches
sleep 5

Which does what your system should do at shutdown anyway.

Pavel