Multimeasure rest number not shown on grand staff with hidden bottom staff

Issue type

Engraving bug (incorrect score rendering)

Description with steps to reproduce

1. Create a score for piano & cello (or any other instrument whose staff is placed below the piano staff
2. Hide the bass clef of the piano staff
3. Enable multimeasure rests

Result:

The piano staff is missing the number on the multimeasure rest.

Supporting files, videos and screenshots

In which versions of MuseScore Studio is this issue present?

All versions since 4.5.2, when the option to display numbers centered between the staves was added

Regression

Yes, this used to work in a previous version of MuseScore 4.x

Operating system

Debian 12

Additional context

It works fine if there is no staff below the piano. I assume the issue is that the code to decide about centering the number is looking for a visible staff below, but not checking to see if it actually belongs to the instrument, until

I set up the steps to be easy to reproduce, but it might seem like an odd corner case. The actual situation where it came up involved a staff hidden when empty and a part containing a subset of the instruments in the score and was rather less contrived.

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