Crash when adding a new scene with empty #57390

New Issue

Mal Duffin · 2018-10-26T12:46:50+02:00

Mal Duffin commented

2018-10-26 12:46:50 +02:00

System Information
Windows 10

Blender Version
Broken: Blender 2.8 Alpha 2 70d73ff500

Short description of error
Blender crashes if you add an empty, then create a new scene. The crash occurs in buttons_context_compute when CTX_data_active_object returns null.

Exact steps for others to reproduce the error

Create a new scene
Delete the cube
Shift A and add an empty
Create a new scene

Blender will crash

**System Information** Windows 10 **Blender Version** Broken: Blender 2.8 Alpha 2 70d73ff5007 **Short description of error** Blender crashes if you add an empty, then create a new scene. The crash occurs in buttons_context_compute when CTX_data_active_object returns null. **Exact steps for others to reproduce the error** 1) Create a new scene 2) Delete the cube 3) Shift A and add an empty 4) Create a new scene Blender will crash

Mal Duffin commented

2018-10-26 12:46:50 +02:00

Added subscriber: @MalDuffin

Mal Duffin commented

2018-10-26 12:51:00 +02:00

I've added a fix for this, I just need to get permissions set up to push it to the repo.

- a/source/blender/editors/space_buttons/buttons_context.c

+++ b/source/blender/editors/space_buttons/buttons_context.c
@@ -647,7 +647,7 @@ void buttons_context_compute(const bContext *C, SpaceButs *sbuts)

                              }
                              else {
                                      Object *ob = CTX_data_active_object(C);

if (ob->type == OB_GPENCIL) {

                                  if (ob && ob->type == OB_GPENCIL) {

                                              sbuts->dataicon = ICON_GREASEPENCIL;
                                      }
                                      else {

I've added a fix for this, I just need to get permissions set up to push it to the repo. - a/source/blender/editors/space_buttons/buttons_context.c +++ b/source/blender/editors/space_buttons/buttons_context.c @@ -647,7 +647,7 @@ void buttons_context_compute(const bContext *C, SpaceButs *sbuts) ``` } else { Object *ob = CTX_data_active_object(C); ``` - if (ob->type == OB_GPENCIL) { + if (ob && ob->type == OB_GPENCIL) { ``` sbuts->dataicon = ICON_GREASEPENCIL; } else {

Philipp Oeser commented

2018-10-26 16:02:26 +02:00

Added subscribers: @antoniov, @brecht, @lichtwerk

Philipp Oeser commented

2018-10-26 16:02:26 +02:00

Can confirm this fixes the crash.
@MalDuffin : for maximum convenience, could you create a diff here ?
Regarding commit rights, see https://wiki.blender.org/wiki/Process/Commit_Rights.

Not sure though if there is a better fix for this [there might be an underlying issue still]

Even with the patch we are still getting an error from UI code:

Traceback (most recent call last):
  File "/scripts/startup/bl_ui/properties_object.py", line 59, in draw
    row.prop(ob, "location")
TypeError: UILayout.prop(): error with argument 1, "data" -  Function.data does not support a 'None' assignment AnyType type

So something is wrong with the buttons context when adding a "New" scene. We shouldnt actually be getting to this part of the code for a context without active object?
2.79 would have changed to the Scene context BCONTEXT_SCENE (and its relating panels) in Properties Editor automatically when you were in e.g. Object context. 2.8 however doesnt do this, it sticks the object context and its panels -- "Transform" etc.

Might just be a refresh/notifier/messagebus thingie, havent looked deeper (will happily do so if the following want me to)
@antoniov: you've added the dependency on active object in that part of the code: have an idea?
@brecht: does the missing refresh (or whatever cause it actually is) ring a bell?

Can confirm this fixes the crash. @MalDuffin : for maximum convenience, could you create a diff [here ](https://developer.blender.org/differential/diff/create/)? Regarding commit rights, see https://wiki.blender.org/wiki/Process/Commit_Rights. Not sure though if there is a better fix for this [there might be an underlying issue still] Even with the patch we are still getting an error from UI code: ``` Traceback (most recent call last): File "/scripts/startup/bl_ui/properties_object.py", line 59, in draw row.prop(ob, "location") TypeError: UILayout.prop(): error with argument 1, "data" - Function.data does not support a 'None' assignment AnyType type ``` So something is wrong with the buttons context when adding a "New" scene. We shouldnt actually be getting to this part of the code for a context without active object? 2.79 would have changed to the Scene context `BCONTEXT_SCENE` (and its relating panels) in Properties Editor automatically when you were in e.g. Object context. 2.8 however doesnt do this, it sticks the object context and its panels -- "Transform" etc. Might just be a refresh/notifier/messagebus thingie, havent looked deeper (will happily do so if the following want me to) @antoniov: you've added the dependency on active object in that part of the code: have an idea? @brecht: does the missing refresh (or whatever cause it actually is) ring a bell?

Brecht Van Lommel commented

2018-10-29 15:45:18 +01:00

This special exception for the grease pencil icon should be removed, it seems to work fine without. It's wrong to base the icon on the object type, it is possible to pin just the grease pencil data without an object.

For the refresh issue, there is a problem in the context path computation in buttons_context_compute() and the various functions that it calls. It should not use CTX_data_scene, CTX_data_view_layer and CTX_data_active_object, because that will read from the (previous) path with the old scene. Instead it should use WM_window_get_active_scene and WM_window_get_active_view_layer (and get the active object from that view layer too).

This special exception for the grease pencil icon should be removed, it seems to work fine without. It's wrong to base the icon on the object type, it is possible to pin just the grease pencil data without an object. For the refresh issue, there is a problem in the context path computation in `buttons_context_compute()` and the various functions that it calls. It should not use `CTX_data_scene`, `CTX_data_view_layer` and `CTX_data_active_object`, because that will read from the (previous) path with the old scene. Instead it should use `WM_window_get_active_scene` and `WM_window_get_active_view_layer` (and get the active object from that view layer too).

Philipp Oeser self-assigned this 2018-10-29 15:54:11 +01:00

Philipp Oeser commented

2018-10-29 15:54:11 +01:00

@brecht: thanx for the explanation, let me see if I can put that together

Antonio Vazquez commented

2018-10-29 17:46:49 +01:00

The dependency to ob->type was a code I added, but testing now it's not needed as Brecht commented bcause the icon is get above.

@lichtwerk Do you want I remove this unneeded code?

The dependency to ob->type was a code I added, but testing now it's not needed as Brecht commented bcause the icon is get above. @lichtwerk Do you want I remove this unneeded code?

Antonio Vazquez commented

2018-10-29 17:50:23 +01:00

I have removed the code related to object in commit: bd7cb42f3d

I have removed the code related to object in commit: bd7cb42f3d4c

Philipp Oeser commented

2018-10-30 19:06:46 +01:00

D3866 should fix the refresh.
Noticed issues with greasepencil pinning [but will move that to a fresh report...]

[D3866](https://archive.blender.org/developer/D3866) should fix the refresh. Noticed issues with greasepencil pinning [but will move that to a fresh report...]

blender-admin commented

2018-11-07 14:51:06 +01:00

This issue was referenced by 36b9ee1277

This issue was referenced by 36b9ee1277519f1ae471afbc0a99e26eee1acbe4

Brecht Van Lommel commented

2018-11-07 14:58:07 +01:00

Changed status from 'Open' to: 'Resolved'

Brecht Van Lommel closed this issue

2018-11-07 14:58:07 +01:00

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Crash when adding a new scene with empty #57390