Crash on undoing setting "Beam middle" property on a single note

I experimented...

I also get the crash if I enter a 1/8 rest followed by a 1/8 note and set "Beam middle" on the rest - i.e. reversing the order of note/rest produced by the steps in the original post. But I get no crash if the "Beam middle" is applied to anything other than a note or rest on the first beat of a score (including the first note/rest of a new system). Thus, I can get the same visual result as with the instructions above with no crash if I enter a 1/8 note followed by a 1/8 rest and set "Beam middle" on that rest. (And we have a workaround.)

It seems that it is the beaming/undoing of something associated with the first beat of a score that causes the crash.

This issue occurs on February 18, 2019

• No crash with this nightly/commit (ie, it's impossible to add a middle beam on a single eighth note): 6469ea4

• Crash with this one (a beam is shaped and crash on Undo) : ab87985

(there is a few commits between them, but seem not involved?)

So a regression of 3.0.5 vs. 3.1(beta)

Fixed in branch master, commit 994c1c130c

_fix #299807: fix a crash on undoing "Beam middle" setting on single note

Prevents a crash by avoiding removing a beam from a score (and
recording this to undo stack) if not really necessary._

Fixed in branch master, commit 71137a8a9c

_Merge pull request #5629 from dmitrio95/299807-crash-beam-middle-single-note

fix #299807: fix a crash on undoing "Beam middle" setting on single note_

Automatically closed -- issue fixed for 2 weeks with no activity.