Corruption / empty measures when pasting measure repeat non-measure-aligned

Issue type

File corruption

Description with steps to reproduce

1. Create score
2. Add some quarter rests for some measures (or anything to subdivide the measure)
3. Create measure repeat somewhere
4. Copy the measure repeat
5. Select a quarter rest not at the start of the measure
6. Paste the measure repeat
   -> measure becomes empty, and the measure after it will contain some rests

Alternative way to reproduce it: paste a measure repeat into a measure that has a different time signature than the measure where the measure repeat comes from.

Expected behaviour: I think pasting measure repeats should behave as pasting a whole-measure rest, possibly unless the measure repeat fits exactly into the target measure (and is being pasted in a measure-aligned position).

Supporting files, videos and screenshots

https://github.com/user-attachments/assets/46fdab50-973b-4709-9548-5fdcc8d7644a

What is the latest version of MuseScore Studio where this issue is present?

4.4 and master

Regression

Yes, this used to work in MuseScore 3.x and now is broken

Operating system

*

Additional context

Demystified version of https://github.com/musescore/MuseScore/issues/23742, originally discovered by @ElixirAmongUs

Checklist

• This report follows the guidelines for reporting bugs and issues
• I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• I have attached all requested files and information to this report
• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible