Cross-staff glissando missing when creating piano part
Steps to reproduce:
1) Create a new score with piano and another instrument
2) Add some cross-staff glissando
3) Create parts
4) Glissando have not been copied to the piano part
Glissando do get propagated when added after part creation.
See the attached file for an example and more details.
Confirmed on Manjaro Linux and Windows 7 (see https://musescore.org/it/node/151066)