Blender crash when using collection user_id remapping (python) #82149

New Issue

Jose Conseco · 2020-10-27T15:56:40+01:00

Jose Conseco commented

2020-10-27 15:56:40 +01:00

System Information
Operating system: Linux-5.8.16-2-MANJARO-x86_64-with-arch-Manjaro-Linux 64 Bits
Graphics card: GeForce GTX 1660 SUPER/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 440.100

Blender Version
Broken: version: 2.91.0 Beta, branch: master, commit date: 2020-10-23 17:33, hash: `70cc0d7121;
Wont work in 2.83 and 2.90 too
Worked: 2.82a
Caused by 37e08e526c

Short description of error
Python script from attached blend file crashes Blender with error:

/snap/blender/47/./blender-wrapper: linie 19: 37036 Naruszenie ochrony pamięci (somthing about memory override error) (zrzut pamięci) $SNAP/blender "$@"

What the script does is:

add and assign custom PropertyGroup property to bpy.types.Collections
create new collection that is used for user remapping of existing collection 'cube_coll'.
if we assign some parameter to new PropertyGroup Parameter blender will crash
Script wont crash if we comment out new property assignment, or user remapping.

The script:

import bpy

class CollectionsSettings(bpy.types.PropertyGroup):
    parent: bpy.props.PointerProperty(name="parent", type=bpy.types.Collection)
    
bpy.utils.register_class(CollectionsSettings)

bpy.types.Collection.prop = bpy.props.PointerProperty(type=CollectionsSettings)

# 4 lines below gives crash
cube_col = bpy.data.collections['Cube_coll']
new_col = bpy.data.collections.new('new_col')
new_col.prop.parent = cube_col

cube_col.id_data.user_remap(new_col)

Exact steps for others to reproduce the error
Just execute script from text editor to see the crash.
col_pointer_crash.blend

**System Information** Operating system: Linux-5.8.16-2-MANJARO-x86_64-with-arch-Manjaro-Linux 64 Bits Graphics card: GeForce GTX 1660 SUPER/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 440.100 **Blender Version** Broken: version: 2.91.0 Beta, branch: master, commit date: 2020-10-23 17:33, hash: `70cc0d7121; Wont work in 2.83 and 2.90 too Worked: 2.82a Caused by 37e08e526c **Short description of error** Python script from attached blend file crashes Blender with error: - /snap/blender/47/./blender-wrapper: linie 19: 37036 Naruszenie ochrony pamięci (somthing about memory override error) (zrzut pamięci) $SNAP/blender "$@" What the script does is: - add and assign custom PropertyGroup property to bpy.types.Collections - create new collection that is used for user remapping of existing collection 'cube_coll'. - if we assign some parameter to new PropertyGroup Parameter blender will crash Script wont crash if we comment out new property assignment, or user remapping. The script: ``` import bpy class CollectionsSettings(bpy.types.PropertyGroup): parent: bpy.props.PointerProperty(name="parent", type=bpy.types.Collection) bpy.utils.register_class(CollectionsSettings) bpy.types.Collection.prop = bpy.props.PointerProperty(type=CollectionsSettings) # 4 lines below gives crash cube_col = bpy.data.collections['Cube_coll'] new_col = bpy.data.collections.new('new_col') new_col.prop.parent = cube_col cube_col.id_data.user_remap(new_col) ``` **Exact steps for others to reproduce the error** Just execute script from text editor to see the crash. [col_pointer_crash.blend](https://archive.blender.org/developer/F9111378/col_pointer_crash.blend)

Jose Conseco commented

2020-10-27 15:56:40 +01:00

Added subscriber: @JoseConseco

Philipp Oeser commented

2020-10-27 17:02:56 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2020-10-27 17:02:56 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Philipp Oeser commented

2020-10-27 17:02:56 +01:00

Can confirm, caused by 37e08e526c

This is only the case if you remap to the same id that holds the property -- and in that case, looks like this enters infinite recursion

1   IDP_foreach_property                                       idprop.c                 1145 0x31b3297 
2   blender::deg::DepsgraphRelationBuilder::build_idproperties deg_builder_relations.cc 578  0xa34c6eb 
3   blender::deg::DepsgraphRelationBuilder::build_collection   deg_builder_relations.cc 594  0xa34c751 
4   blender::deg::DepsgraphRelationBuilder::build_id           deg_builder_relations.cc 497  0xa34c35e 
5   blender::deg::build_idproperties_callback                  deg_builder_relations.cc 573  0xa34c6b9 
6   IDP_foreach_property                                       idprop.c                 1151 0x31b32e6 
7   IDP_foreach_property                                       idprop.c                 1158 0x31b3325 
8   IDP_foreach_property                                       idprop.c                 1158 0x31b3325 
9   blender::deg::DepsgraphRelationBuilder::build_idproperties deg_builder_relations.cc 578  0xa34c6eb 
10  blender::deg::DepsgraphRelationBuilder::build_collection   deg_builder_relations.cc 594  0xa34c751 
11  blender::deg::DepsgraphRelationBuilder::build_id           deg_builder_relations.cc 497  0xa34c35e 
12  blender::deg::build_idproperties_callback                  deg_builder_relations.cc 573  0xa34c6b9 
13  IDP_foreach_property                                       idprop.c                 1151 0x31b32e6 
14  IDP_foreach_property                                       idprop.c                 1158 0x31b3325 
15  IDP_foreach_property                                       idprop.c                 1158 0x31b3325 
16  blender::deg::DepsgraphRelationBuilder::build_idproperties deg_builder_relations.cc 578  0xa34c6eb 
17  blender::deg::DepsgraphRelationBuilder::build_collection   deg_builder_relations.cc 594  0xa34c751 
18  blender::deg::DepsgraphRelationBuilder::build_id           deg_builder_relations.cc 497  0xa34c35e 
19  blender::deg::build_idproperties_callback                  deg_builder_relations.cc 573  0xa34c6b9 
20  IDP_foreach_property                                       idprop.c                 1151 0x31b32e6 
... <More>

So if you remap to something else, no crash occurs

import bpy

class CollectionsSettings(bpy.types.PropertyGroup):
    parent: bpy.props.PointerProperty(name="parent", type=bpy.types.Collection)
    
bpy.utils.register_class(CollectionsSettings)

bpy.types.Collection.prop = bpy.props.PointerProperty(type=CollectionsSettings)

# no crash
cube_col = bpy.data.collections['Cube_coll']
new_col = bpy.data.collections.new('new_col')
third_col = bpy.data.collections.new('third_col')
new_col.prop.parent = cube_col

cube_col.id_data.user_remap(third_col)

Can confirm, caused by 37e08e526c This is only the case if you remap to the same id that holds the property -- and in that case, looks like this enters infinite recursion ``` 1 IDP_foreach_property idprop.c 1145 0x31b3297 2 blender::deg::DepsgraphRelationBuilder::build_idproperties deg_builder_relations.cc 578 0xa34c6eb 3 blender::deg::DepsgraphRelationBuilder::build_collection deg_builder_relations.cc 594 0xa34c751 4 blender::deg::DepsgraphRelationBuilder::build_id deg_builder_relations.cc 497 0xa34c35e 5 blender::deg::build_idproperties_callback deg_builder_relations.cc 573 0xa34c6b9 6 IDP_foreach_property idprop.c 1151 0x31b32e6 7 IDP_foreach_property idprop.c 1158 0x31b3325 8 IDP_foreach_property idprop.c 1158 0x31b3325 9 blender::deg::DepsgraphRelationBuilder::build_idproperties deg_builder_relations.cc 578 0xa34c6eb 10 blender::deg::DepsgraphRelationBuilder::build_collection deg_builder_relations.cc 594 0xa34c751 11 blender::deg::DepsgraphRelationBuilder::build_id deg_builder_relations.cc 497 0xa34c35e 12 blender::deg::build_idproperties_callback deg_builder_relations.cc 573 0xa34c6b9 13 IDP_foreach_property idprop.c 1151 0x31b32e6 14 IDP_foreach_property idprop.c 1158 0x31b3325 15 IDP_foreach_property idprop.c 1158 0x31b3325 16 blender::deg::DepsgraphRelationBuilder::build_idproperties deg_builder_relations.cc 578 0xa34c6eb 17 blender::deg::DepsgraphRelationBuilder::build_collection deg_builder_relations.cc 594 0xa34c751 18 blender::deg::DepsgraphRelationBuilder::build_id deg_builder_relations.cc 497 0xa34c35e 19 blender::deg::build_idproperties_callback deg_builder_relations.cc 573 0xa34c6b9 20 IDP_foreach_property idprop.c 1151 0x31b32e6 ... <More> ``` So if you remap to something else, no crash occurs ``` import bpy class CollectionsSettings(bpy.types.PropertyGroup): parent: bpy.props.PointerProperty(name="parent", type=bpy.types.Collection) bpy.utils.register_class(CollectionsSettings) bpy.types.Collection.prop = bpy.props.PointerProperty(type=CollectionsSettings) # no crash cube_col = bpy.data.collections['Cube_coll'] new_col = bpy.data.collections.new('new_col') third_col = bpy.data.collections.new('third_col') new_col.prop.parent = cube_col cube_col.id_data.user_remap(third_col) ```

Jose Conseco commented

2020-10-27 18:09:11 +01:00

Thx @lichtwerk I may simplified the script too much, but you are right. If I remap 'cube_col' first, then point cube_col to new_col we get no crash (no loop pointer to itself)
However in a bit more complicated case it will still crash:

import bpy

class CollectionsSettings(bpy.types.PropertyGroup):
    parent: bpy.props.PointerProperty(name="parent", type=bpy.types.Collection)
bpy.utils.register_class(CollectionsSettings)

bpy.types.Collection.prop = bpy.props.PointerProperty(type=CollectionsSettings)

# 4 lines below gives crash
cube_col = bpy.data.collections['Cube_coll']
new_col = bpy.data.collections.new('new_col')
cube_col.id_data.user_remap(new_col)                              # remap first so no cyclip loop
new_col.prop.parent = cube_col            # A points to B
cube_col.prop.parent = new_col            # B points to A

I guess you may say there is still loop
new_col points to cube_col ; then cube_col points back to new_col; etc
It worked it 2.82 though. IMO blender could/should check for loop like those.

Thx @lichtwerk I may simplified the script too much, but you are right. If I remap 'cube_col' first, then point cube_col to new_col we get no crash (no loop pointer to itself) However in a bit more complicated case it will still crash: ``` import bpy class CollectionsSettings(bpy.types.PropertyGroup): parent: bpy.props.PointerProperty(name="parent", type=bpy.types.Collection) bpy.utils.register_class(CollectionsSettings) bpy.types.Collection.prop = bpy.props.PointerProperty(type=CollectionsSettings) # 4 lines below gives crash cube_col = bpy.data.collections['Cube_coll'] new_col = bpy.data.collections.new('new_col') cube_col.id_data.user_remap(new_col) # remap first so no cyclip loop new_col.prop.parent = cube_col # A points to B cube_col.prop.parent = new_col # B points to A ``` I guess you may say there is still loop new_col points to cube_col ; then cube_col points back to new_col; etc It worked it 2.82 though. IMO blender could/should check for loop like those.

Bastien Montagne self-assigned this 2020-10-27 19:23:00 +01:00

blender-admin commented

2020-10-28 11:04:49 +01:00

This issue was referenced by 0d772221c6

This issue was referenced by 0d772221c64187b5004dd687888042f44603257d

Bastien Montagne commented

2020-10-28 11:08:10 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Bastien Montagne closed this issue

2020-10-28 11:08:10 +01:00

Thomas Dinges added this to the 2.91 milestone 2023-02-08 16:20:09 +01:00

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Blender crash when using collection user_id remapping (python) #82149