[MusicXML export] missing staff in harmony
Reported version
3.4
Type
Functional
Frequency
Once
Severity
S4 - Minor
Reproducibility
Always
Status
active
Regression
No
Workaround
No
Project
Existing bug exposed by new test file testHarmony6 in pull request https://github.com/musescore/MuseScore/pull/5958 commit 6ff0246: in a multi-staff context, a harmony element should have a child element staff.
Note that this issue does NOT lead to invalid MusicXML and that the staff is implicitly defined by the following note. It does not seem very likely that this issue would cause import errors.
Trivial to fix.