Crash: Python Operator Create New Object Then Undo #81346

New Issue

Wayde Moss · 2020-10-01T09:39:56+02:00

Wayde Moss commented

2020-10-01 09:39:56 +02:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 441.66

Blender Version
Broken: version: 2.90.0, branch: master, commit date: 2020-08-31 11:26, hash: 0330d1af29
2.83.4
2.83.0
2.91 (build from September 29, 2020)

Worked: (newest version of Blender that worked as expected)
2.82.7
2.81.16

Short description of error
Undoing an operator that creates an object and links it to a collection will crash Blender. Oddly enough, doing the same thing but outside an operator will not crash Blender on undo. The video shows both cases.

Exact steps for others to reproduce the error
The provided file will open with the proper UI.
Run script
In View3D, open "Crash" Tab (N) and press "Simple Object Operator" button.
Undo (crashes)

undo_new_object_from_operator.blend
Crash:
crash.mp4
Similar But No Crash:
similar_but_no_crash.mp4

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 441.66 **Blender Version** Broken: version: 2.90.0, branch: master, commit date: 2020-08-31 11:26, hash: `0330d1af29` 2.83.4 2.83.0 2.91 (build from September 29, 2020) Worked: (newest version of Blender that worked as expected) 2.82.7 2.81.16 **Short description of error** Undoing an operator that creates an object and links it to a collection will crash Blender. Oddly enough, doing the same thing but outside an operator will not crash Blender on undo. The video shows both cases. **Exact steps for others to reproduce the error** The provided file will open with the proper UI. Run script In View3D, open "Crash" Tab (N) and press "Simple Object Operator" button. Undo (crashes) [undo_new_object_from_operator.blend](https://archive.blender.org/developer/F8943097/undo_new_object_from_operator.blend) Crash: [crash.mp4](https://archive.blender.org/developer/F8943136/crash.mp4) Similar But No Crash: [similar_but_no_crash.mp4](https://archive.blender.org/developer/F8943135/similar_but_no_crash.mp4)

Wayde Moss commented

2020-10-01 09:39:56 +02:00

Added subscriber: @wbmoss_dev

Philipp Oeser commented

2020-10-01 12:06:16 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2020-10-01 12:06:16 +02:00

Looks like #77557 (Python Operators that add/remove ID data without an undo step crash Blender)

Since the new Undo system in 2.83, you have to add an Undo push to operators that add or remove ID data

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"
    bl_options = {'UNDO'}

Doing this will prevent the crash

Or: use the Undo Legacy option in User Preferences > Experimental > Debugging

So, this is a known thing (will merge this report into #77557), but you have a workaround to fix this already (add the UNDO option to your operator).

Looks like #77557 (Python Operators that add/remove ID data without an undo step crash Blender) Since the new Undo system in 2.83, you have to add an Undo push to operators that add or remove ID data ``` class SimpleOperator(bpy.types.Operator): """Tooltip""" bl_idname = "object.simple_operator" bl_label = "Simple Object Operator" bl_options = {'UNDO'} ``` Doing this will prevent the crash Or: use the `Undo Legacy` option in `User Preferences` > `Experimental` > `Debugging` So, this is a known thing (will merge this report into #77557), but you have a workaround to fix this already (add the UNDO option to your operator).

Philipp Oeser commented

2020-10-01 12:06:28 +02:00

Closed as duplicate of #77557

Philipp Oeser closed this issue

2020-10-01 12:06:28 +02:00

Wayde Moss commented

2020-10-02 00:58:22 +02:00

Thanks, the workarounds (manually pushing undo) in the other report works for my actual use case.

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Crash: Python Operator Create New Object Then Undo #81346