Crash. Script changing values of a prop attached to object by an operator popup crashes the app #60553

New Issue

Evgeniy Skvortsov · 2019-01-16T06:57:49+01:00

Evgeniy Skvortsov commented

2019-01-16 06:57:49 +01:00

System Information
Operating system: Windows 10 Pro
Graphics card: NVidia GTX 1070 Ti

Blender Version
Broken:
(example: 2.80, edbf15d3c0, blender2.8, 2018-11-28, as found on the splash screen)
Worked: (optional)

Short description of error
When used from a plugin, operator that uses wm.invoke_props_popup(self, event) to draw(and change) properties from a property group attached to an object (constantly) crashes the app.
When same code is used from the blender scripting area, the app does not crash, but after initial change of the param, the property is grayed out(seems like a bug as well).
Error : EXCEPTION_ACCESS_VIOLATION
Address : 0x00007FF7DDBEA080
Module : c:\Blender28\program\blender.exe
The terminal process terminated with exit code: 11

Exact steps for others to reproduce the error

Create a testing_grounds.py file
Fill it with code provided below
Install as an addon
Select an object
Launch the operator(through space, typing "TEZZT")
Change the value of the property by clicking and dragging the value;
Repeat step (6) a few times if the app hasn't crashed yet

bl_info = {
    "name" : "TestingGrounds",
    "author" : "ChieVFX",
    "description" : "",
    "blender" : (2, 80, 0),
    "location" : "",
    "warning" : "",
    "category" : "Generic"
}

import bpy

class SomeParams(bpy.types.PropertyGroup):
    float_value : bpy.props.FloatProperty()

class TestOp(bpy.types.Operator):
    bl_idname="testing_ground.tezzt"
    bl_label="TEZZT"
    bl_options={'REGISTER', 'UNDO'}

    def invoke(self, context, event):
        wm = context.window_manager
        return wm.invoke_props_popup(self, event)
    
    def execute(self, context):
        print("Im fine")
        return {'FINISHED'}
    
    def draw(self, context):
        layout : bpy.types.UILayout = self.layout
        obj = context.object
        some_params = obj.some_params
        layout.prop(some_params, "float_value", text="Prop popup test")
        
classes = [
    SomeParams,
    TestOp
]

def register():
    for cls in classes:
        bpy.utils.register_class(cls)
    
    bpy.types.Object.some_params = bpy.props.PointerProperty(type=SomeParams)


def unregister():
    for cls in classes:
        bpy.utils.unregister_class(cls)
    
if __name__ == "__main__":
    register()
    bpy.ops.testing_ground.tezzt('INVOKE_DEFAULT')

**System Information** Operating system: Windows 10 Pro Graphics card: NVidia GTX 1070 Ti **Blender Version** Broken: (example: 2.80, edbf15d3c044, blender2.8, 2018-11-28, as found on the splash screen) Worked: (optional) **Short description of error** When used from a plugin, operator that uses wm.invoke_props_popup(self, event) to draw(and change) properties from a property group attached to an object (constantly) crashes the app. When same code is used from the blender scripting area, the app does not crash, but after initial change of the param, the property is grayed out(seems like a bug as well). Error : EXCEPTION_ACCESS_VIOLATION Address : 0x00007FF7DDBEA080 Module : c:\Blender28\program\blender.exe The terminal process terminated with exit code: 11 **Exact steps for others to reproduce the error** 1) Create a testing_grounds.py file 2) Fill it with code provided below 3) Install as an addon 4) Select an object 5) Launch the operator(through space, typing "TEZZT") 6) Change the value of the property by clicking and dragging the value; 7) Repeat step (6) a few times if the app hasn't crashed yet ``` bl_info = { "name" : "TestingGrounds", "author" : "ChieVFX", "description" : "", "blender" : (2, 80, 0), "location" : "", "warning" : "", "category" : "Generic" } import bpy class SomeParams(bpy.types.PropertyGroup): float_value : bpy.props.FloatProperty() class TestOp(bpy.types.Operator): bl_idname="testing_ground.tezzt" bl_label="TEZZT" bl_options={'REGISTER', 'UNDO'} def invoke(self, context, event): wm = context.window_manager return wm.invoke_props_popup(self, event) def execute(self, context): print("Im fine") return {'FINISHED'} def draw(self, context): layout : bpy.types.UILayout = self.layout obj = context.object some_params = obj.some_params layout.prop(some_params, "float_value", text="Prop popup test") classes = [ SomeParams, TestOp ] def register(): for cls in classes: bpy.utils.register_class(cls) bpy.types.Object.some_params = bpy.props.PointerProperty(type=SomeParams) def unregister(): for cls in classes: bpy.utils.unregister_class(cls) if __name__ == "__main__": register() bpy.ops.testing_ground.tezzt('INVOKE_DEFAULT') ```

Evgeniy Skvortsov commented

2019-01-16 06:57:49 +01:00

Added subscriber: @ChieVFX

blender-admin commented

2019-01-16 06:57:49 +01:00

#60605 was marked as duplicate of this issue

Evgeniy Skvortsov commented

2019-01-16 07:18:31 +01:00

I realize that it might be intentional and is not a deal-breaker.
Using duplicating props in the operator whose values are then set on execute to the object's prop seems to work fine.

I realize that it might be intentional and is not a deal-breaker. Using duplicating props in the operator whose values are then set on execute to the object's prop seems to work fine.

Jacques Lucke commented

2019-01-16 12:35:30 +01:00

Added subscriber: @JacquesLucke

Jacques Lucke commented

2019-01-16 12:35:30 +01:00

It's certainly not typical to show properties that don't belong to the operator in this place. However, I don't see why this should crash.
Note: you can reproduce this without creating an addon. Just execute the code in Blenders Text editor.

__GI_raise(int sig) (/build/glibc-OTsEL5/glibc-2.27/sysdeps/unix/sysv/linux/raise.c:51)
__GI_abort() (/build/glibc-OTsEL5/glibc-2.27/stdlib/abort.c:79)
BKE_idcode_to_index(const short idcode) (/home/jacques/blender-git/blender/source/blender/blenkernel/intern/idcode.c:315)
DEG_id_type_tag(Main * bmain, short id_type) (/home/jacques/blender-git/blender/source/blender/depsgraph/intern/depsgraph_tag.cc:658)
DEG::(anonymous namespace)::deg_graph_id_tag_update(Main * bmain, DEG::Depsgraph * graph, ID * id, int flag) (/home/jacques/blender-git/blender/source/blender/depsgraph/intern/depsgraph_tag.cc:462)
DEG::(anonymous namespace)::deg_id_tag_update(Main * bmain, ID * id, int flag) (/home/jacques/blender-git/blender/source/blender/depsgraph/intern/depsgraph_tag.cc:488)
DEG_id_tag_update_ex(Main * bmain, ID * id, int flag) (/home/jacques/blender-git/blender/source/blender/depsgraph/intern/depsgraph_tag.cc:632)
DEG_id_tag_update(ID * id, int flag) (/home/jacques/blender-git/blender/source/blender/depsgraph/intern/depsgraph_tag.cc:623)
rna_property_update(bContext * C, Main * bmain, Scene * scene, PointerRNA * ptr, PropertyRNA * prop) (/home/jacques/blender-git/blender/source/blender/makesrna/intern/rna_access.c:2200)
RNA_property_update(bContext * C, PointerRNA * ptr, PropertyRNA * prop) (/home/jacques/blender-git/blender/source/blender/makesrna/intern/rna_access.c:2233)
ui_apply_but_funcs_after(bContext * C) (/home/jacques/blender-git/blender/source/blender/editors/interface/interface_handlers.c:782)
ui_popup_handler(bContext * C, const wmEvent * event, void * userdata) (/home/jacques/blender-git/blender/source/blender/editors/interface/interface_handlers.c:9939)
wm_handler_ui_call(bContext * C, wmEventHandler * handler, const wmEvent * event, int always_pass) (/home/jacques/blender-git/blender/source/blender/windowmanager/intern/wm_event_system.c:573)
wm_handlers_do_intern(bContext * C, wmEvent * event, ListBase * handlers) (/home/jacques/blender-git/blender/source/blender/windowmanager/intern/wm_event_system.c:2374)
wm_handlers_do(bContext * C, wmEvent * event, ListBase * handlers) (/home/jacques/blender-git/blender/source/blender/windowmanager/intern/wm_event_system.c:2607)
wm_event_do_handlers(bContext * C) (/home/jacques/blender-git/blender/source/blender/windowmanager/intern/wm_event_system.c:2997)
WM_main(bContext * C) (/home/jacques/blender-git/blender/source/blender/windowmanager/intern/wm.c:427)
main(int argc, const char ** argv) (/home/jacques/blender-git/blender/source/creator/creator.c:523)

It's certainly not typical to show properties that don't belong to the operator in this place. However, I don't see why this should crash. Note: you can reproduce this without creating an addon. Just execute the code in Blenders Text editor. ``` __GI_raise(int sig) (/build/glibc-OTsEL5/glibc-2.27/sysdeps/unix/sysv/linux/raise.c:51) __GI_abort() (/build/glibc-OTsEL5/glibc-2.27/stdlib/abort.c:79) BKE_idcode_to_index(const short idcode) (/home/jacques/blender-git/blender/source/blender/blenkernel/intern/idcode.c:315) DEG_id_type_tag(Main * bmain, short id_type) (/home/jacques/blender-git/blender/source/blender/depsgraph/intern/depsgraph_tag.cc:658) DEG::(anonymous namespace)::deg_graph_id_tag_update(Main * bmain, DEG::Depsgraph * graph, ID * id, int flag) (/home/jacques/blender-git/blender/source/blender/depsgraph/intern/depsgraph_tag.cc:462) DEG::(anonymous namespace)::deg_id_tag_update(Main * bmain, ID * id, int flag) (/home/jacques/blender-git/blender/source/blender/depsgraph/intern/depsgraph_tag.cc:488) DEG_id_tag_update_ex(Main * bmain, ID * id, int flag) (/home/jacques/blender-git/blender/source/blender/depsgraph/intern/depsgraph_tag.cc:632) DEG_id_tag_update(ID * id, int flag) (/home/jacques/blender-git/blender/source/blender/depsgraph/intern/depsgraph_tag.cc:623) rna_property_update(bContext * C, Main * bmain, Scene * scene, PointerRNA * ptr, PropertyRNA * prop) (/home/jacques/blender-git/blender/source/blender/makesrna/intern/rna_access.c:2200) RNA_property_update(bContext * C, PointerRNA * ptr, PropertyRNA * prop) (/home/jacques/blender-git/blender/source/blender/makesrna/intern/rna_access.c:2233) ui_apply_but_funcs_after(bContext * C) (/home/jacques/blender-git/blender/source/blender/editors/interface/interface_handlers.c:782) ui_popup_handler(bContext * C, const wmEvent * event, void * userdata) (/home/jacques/blender-git/blender/source/blender/editors/interface/interface_handlers.c:9939) wm_handler_ui_call(bContext * C, wmEventHandler * handler, const wmEvent * event, int always_pass) (/home/jacques/blender-git/blender/source/blender/windowmanager/intern/wm_event_system.c:573) wm_handlers_do_intern(bContext * C, wmEvent * event, ListBase * handlers) (/home/jacques/blender-git/blender/source/blender/windowmanager/intern/wm_event_system.c:2374) wm_handlers_do(bContext * C, wmEvent * event, ListBase * handlers) (/home/jacques/blender-git/blender/source/blender/windowmanager/intern/wm_event_system.c:2607) wm_event_do_handlers(bContext * C) (/home/jacques/blender-git/blender/source/blender/windowmanager/intern/wm_event_system.c:2997) WM_main(bContext * C) (/home/jacques/blender-git/blender/source/blender/windowmanager/intern/wm.c:427) main(int argc, const char ** argv) (/home/jacques/blender-git/blender/source/creator/creator.c:523) ```

Campbell Barton was assigned by Jacques Lucke

2019-03-20 15:35:40 +01:00

Jacques Lucke commented

2019-03-20 15:35:40 +01:00

Looks like the following is happening:

The draw function of the popover is called. This stores the pointer to the active object in the uibut (?) somewhere.
Then, when undo is executed (because of operator redo), the pointer to the active object changes. The problem is that the now-invalid pointer is still used.

Some printf debugging output:

context.active_object in draw:       0x7fffaa139838
ptr->id.data in rna_property_update: 0x7fffaa139838
name: OBCube
context.active_object in execute:    0x7fffaa139838
ptr->id.data in rna_property_update: 0x7fffaa139838
name: OBCube
redo_cb: operator redo TEZZT
context.active_object in execute:    0x7fffaa142838     <- new active object pointer after undo
ptr->id.data in rna_property_update: 0x7fffaa139838     <- still the old pointer
name: <crash>

Looks like the following is happening: 1. The draw function of the popover is called. This stores the pointer to the active object in the uibut (?) somewhere. 2. Then, when undo is executed (because of operator redo), the pointer to the active object changes. The problem is that the now-invalid pointer is still used. Some printf debugging output: ``` context.active_object in draw: 0x7fffaa139838 ptr->id.data in rna_property_update: 0x7fffaa139838 name: OBCube context.active_object in execute: 0x7fffaa139838 ptr->id.data in rna_property_update: 0x7fffaa139838 name: OBCube redo_cb: operator redo TEZZT context.active_object in execute: 0x7fffaa142838 <- new active object pointer after undo ptr->id.data in rna_property_update: 0x7fffaa139838 <- still the old pointer name: <crash> ```

Campbell Barton was unassigned by Dalai Felinto

2019-12-23 16:35:22 +01:00

Dalai Felinto commented

2019-12-23 16:35:22 +01:00

Added subscriber: @ideasman42

Radu Popovici commented

2020-05-30 15:07:44 +02:00

Added subscriber: @rpopovici

Radu Popovici commented

2020-05-30 15:07:44 +02:00

I had a similar issue. Adding a redo handler with a view_layer.update() inside fixed the crash in my case.

@persistent
def redo_update_handler_post(scene):
    # fix crash in redo
    bpy.context.view_layer.update()

I had a similar issue. Adding a redo handler with a view_layer.update() inside fixed the crash in my case. ``` @persistent def redo_update_handler_post(scene): # fix crash in redo bpy.context.view_layer.update() ```

Philipp Oeser removed the

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Crash. Script changing values of a prop attached to object by an operator popup crashes the app #60553