bpy.data.meshes.new_from_object() doesn't increment user count for materials referenced by the mesh #65352

New Issue

Ivan Lyubovnikov · 2019-05-31T15:59:03+02:00

Ivan Lyubovnikov commented

2019-05-31 15:59:03 +02:00

System Information
Operating system: Linux-4.18.0-10-lowlatency-x86_64-with-debian-buster-sid 64 Bits
Graphics card: AMD RAVEN (DRM 3.26.0, 4.18.0-10-lowlatency, LLVM 7.0.0) X.Org 4.5 (Core Profile) Mesa 18.2.8

Blender Version
Broken: version: 2.80 (sub 73), branch: blender2.7, commit date: 2019-05-30 22:28, hash: fc336f973d
Worked: (optional)

Short description of error
When using bpy.data.meshes.new_from_object() for an object with a material, the amount of users for that material stays the same despite that the newly generated mesh also references it.
After removing the generated mesh with bpy.data.meshes.remove() the number of users becomes 0 also making the material on the original object look invalid in the interface:

Exact steps for others to reproduce the error

open the attached blend file
run the active script in the Text Editor
see the output in the console and the material data-block highlighted in red in the Shader Editor

test.blend

**System Information** Operating system: Linux-4.18.0-10-lowlatency-x86_64-with-debian-buster-sid 64 Bits Graphics card: AMD RAVEN (DRM 3.26.0, 4.18.0-10-lowlatency, LLVM 7.0.0) X.Org 4.5 (Core Profile) Mesa 18.2.8 **Blender Version** Broken: version: 2.80 (sub 73), branch: blender2.7, commit date: 2019-05-30 22:28, hash: `fc336f973d` Worked: (optional) **Short description of error** When using bpy.data.meshes.new_from_object() for an object with a material, the amount of users for that material stays the same despite that the newly generated mesh also references it. After removing the generated mesh with bpy.data.meshes.remove() the number of users becomes 0 also making the material on the original object look invalid in the interface: ![material_no_users.png](https://archive.blender.org/developer/F7081298/material_no_users.png) **Exact steps for others to reproduce the error** 1) open the attached blend file 2) run the active script in the Text Editor 3) see the output in the console and the material data-block highlighted in red in the Shader Editor [test.blend](https://archive.blender.org/developer/F7081308/test.blend)

Ivan Lyubovnikov commented

2019-05-31 15:59:03 +02:00

Added subscriber: @ivan_lyubovnikov

Alexander Kovelenov commented

2019-05-31 16:04:13 +02:00

Added subscriber: @AlexKowel

Ivan Lyubovnikov commented

2019-05-31 16:20:07 +02:00

After some testing it appears that the breaking change was in 392e58afb321

After some testing it appears that the breaking change was in [392e58afb321 ](https://developer.blender.org/rB392e58afb32162d7d31e5cfc0d6206382e7e7d62)

Dalai Felinto commented

2019-05-31 17:04:44 +02:00

Added subscriber: @dfelinto

Bastien Montagne was assigned by Dalai Felinto

2019-05-31 17:04:44 +02:00

Dalai Felinto commented

2019-05-31 17:04:44 +02:00

If the issue started on 392e58afb3, let's have Bastien to look at it.

If the issue started on 392e58afb321, let's have Bastien to look at it.

blender-admin commented

2019-06-03 20:59:13 +02:00

This issue was referenced by d62a749fcf

This issue was referenced by d62a749fcf4848958d748a4d5ef5c4f1172cd351

Bastien Montagne commented

2019-06-03 21:01:25 +02:00

Changed status from 'Open' to: 'Resolved'

Bastien Montagne closed this issue

2019-06-03 21:01:25 +02:00

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bpy.data.meshes.new_from_object() doesn't increment user count for materials referenced by the mesh #65352