Undo in Song Editor Fails After Duplicating Multiple Midi Reigions

[tinkerlevu]

Bug Summary

LMMS fails to to properly undo an operation where midi regions from two separate instrument tracks are duplicated.
This has also randomly caused crashes or instability.

Steps to reproduce

1. Create two instrument tracks next to each other in the song editor.
2. Create a Midi regions in each track and populate them with notes.
3. Select the multiple Midi regions simultaneously.
4. Use Ctrl+drag to duplicate the selected reigions to other positions in the tracks
5. Use Ctrl + Z to attempt an Undo

Expected behavior

The two duplicates are deleted.

Actual behavior

Only the duplicates in one of the instrument tracks are deleted.
A crash may occur depending on the instrument and project.

Screenshot

Affected LMMS versions

1.3.0 Alpha

Logs

Click to expand

Carla appears to be installed on this system at /usr/lib[64]/carla so we'll use it.
Jack appears to be installed on this system, so we'll use it.
Lv2 plugin SUMMARY: 95 of 192  loaded in 1550 msecs.
For details about not loaded plugins, please set
  environment variable "LMMS_LV2_DEBUG" to nonempty.
Lv2 Plugins blacklisted: 2 of 192 
  If you want to ignore the blacklist (dangerous!), please set
  environment variable "LMMS_IGNORE_BLACKLIST" to nonempty.