Previous time signatures affecting later beaming

[Postoli]

Issue type

Engraving bug (incorrect score rendering)

Bug description

In this score, I have a 15/16 bar, followed by a 7/8 bar. Before this point, 4/4 was beamed as 4+4. However following this point, all beams of 4 (or 6) are split into two, EVEN THOUGH the Time Signature properties for future time signatures (4/4, 6/4) outline beams should be grouped (i.e. 4+4, 6+6, not 2+2+2+2 etc.). BUT, strangely, when a bar is placed between the 15/16 and 7/8, this resolves the issue.

Steps to reproduce

1. Insert a 15/16 bar
2. Insert a 7/8 bar IMMEDIATELY after
3. Insert a 4/4 some place after
4. Insert 8 quavers in the 4/4 bar. Note how they are beamed in twos, even though the Time Sig properties outlines it should be grouped as fours.

Screenshots/Screen recordings

MuseScore Version

4.2.1

Regression

I don't know

Operating system

macOS Sonoma

Additional context

No response

[DaddyLudwig]

Seems somewhat related to this issue I encountered months ago with a Mozart cadenza, like they probably have the same root cause. Not a nominal time signature change in my case, but a joining of measures to make a cadenza that is 57/16 in length. Also causing eighths in 4/4 to be split into groups of 2 when it shouldn't be.

#17905

And I encountered similar beaming issues in 4/4 when making a 1/32 pickup via Measure Properties at the start of a Beethoven cello sonata as well. 3 different causes, same result, there's gotta be something at the root of all this.

[Earlgrey99]

Hi,

I'm a university student looking to contribute to MuseScore for a class project. I'd like to take a look at this bug.

[GreeeenCat]

I am having a similar issue, with the same problem occurring after an anacrusis.

[henkdegroot]

Came up in this as well: https://musescore.org/en/node/377529

Just in case it help, just creating a pickup measure with a duration of 1/16 or less has this effect on the beaming in group of 2 eight notes. Increase the duration of the pickup measure to 1/8 instantly resolves the beaming and grouping is back to 4. I used 4/4 time signature for my test.