**System Information**
Operating system: Linux-4.15.0-96-generic-x86_64-with-debian-buster-sid 64 Bits
Graphics card: GeForce GTX 1050/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 435.21
**Blender Version**
Broken: version: 2.83.0 Beta, branch: master, commit date: 2020-05-30 15:33, hash: `rBec26260132b4`
Worked: `rB1239cab11ff9`
**Short description of error**
Using a custom operator to append an object from another file, will crash Blender when undoing right after.
Curiously, the operator has to be called from a menu (like the operator search menu), and won't crash when run from the text editor.
{F8569400}
**Exact steps for others to reproduce the error**
* open the append_obj_undo_crash.blend file from the zip
* run the script in the text editor to register the AppendUndoCrash operator
* run Append Undo Crash from the operator search menu in the 3d view