Fix saving scores opened by relative pathname from cmdline

[mirabilos]

https://musescore.org/en/node/150956

The patch was tested against the 2.1 release and committed relative to the 2.2 branch.

[Jojo-Schmitz]

As far as I can see it should apply cleanly to master too.
If you make the commit message starting with fix #150956:, that issue will get marked as fixed automagically once ths PR gets merged

[mirabilos]

Thanks, I’ve updated the commit message.

As scorefile.cpp didn’t change between 2.1 and 2.2 it should work; master does contain some changes, but (in the function affected) only in the way things were translated, so it will likely just work there as well, yes.

[Jojo-Schmitz]

Yes, I manually checked that this PR should not cause merge conflits with master, so should cherrypick cleanly

[mirabilos]

@lasconic can we pretty please have this in 2.2? I’ve been carrying it in the Debian package since like forever…

[lasconic]

Merged, also on master 28a54f3

[mirabilos]

Thanks!