Corruption of files when adding local time signatures

[oktophonie]

(Originally posted by mozbadel in https://github.com/orgs/musescore/discussions/16817):

For some years I have been trying to complete my transcription of Mother Goose but failing because of corruptions when using time signature changes for some (but not all) instruments.

I have also raised this issue in the support section of the forum on musescore.org. The four attached four files here (in the zip below) with subscripts a through d show:

a) 2/4 successfully added to Celesta at rehearsal mark 17 b) 2/4 successfully added to 2nd Violins at rehearsal mark 17 c) 6/8 successfully added to Violas (Altos) at rehearsal mark 17 d) 6/8 causing corruption to file when added to 2nd Violins at rehearsal mark 18

mothergoose.zip

There have been no notes added to the files at all as yet.

Saith Marc Sabatella:

I can confirm the problem that occurs with the following steps:

1) load "c" version of the score 2) use Ctrl+drag to add 6/8 to top violin 2 at rehearsal mark 18 3) save

Using 4.0.2, the corruption is reported immediately upon saving, giving you an opportunity to fix it right away. And luckily, it's trivially simple to fix. Just select those (empty) measures and hit Delete.

[oktophonie]

I found what I think is a variant of this (if not the same thing).

Start with this:

If we add a local time sig subsequently to return to the 'global' time sig of 2/4, it will treat all parts as having bars of that length (though as you can see here, the oboe is now spaced as though there are going to be 3 quarters in that bar:

A corruption will be reported when trying to save, after this point.