Opening Blender's File Chooser from a Dialog Causes Blender to Crash #65511

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Grant Wilk · 2019-06-05T06:45:44+02:00

Grant Wilk commented

2019-06-05 06:45:44 +02:00

System Information
Operating system: Windows 10 Pro
Graphics card: (2x) NVIDIA GeForce GTX 1070

Blender Version
Broken: 2.80, c13e10a740, 2019-06-04
Worked: 2.79b, f4dc9f9d68, 2018-03-22

Short description of error
Creating a Python script that opens Blender's file chooser from a dialog will cause Blender to crash.

For ease of reproduction and demonstration, I have included a Blender file that contains a short Python script that causes this issue. The script is supposed to do the following once it is run:

Display a confirmation dialog asking the user if they would like to open a file chooser
Upon confirmation, open the file chooser.

Upon file selection, print the file's filepath to the console.

This code does functions properly in Blender 2.79b (hash mentioned above), but it causes a crash in Blender 2.80.

For some reason, using the execute function of the primary dialog operator, TEST_OT_primary_dialog, to call either of the file-chooser invoking operators, TEST_OT_invoke_file_chooser_1 or TEST_OT_invoke_file_chooser_2, causes Blender 2.80 to crash.

Exact steps for others to reproduce the error

Download and open the Blender file from below. It is a 2.79b file, but should open in 2.80 as well.
Click the "Run Script" button in the text editor. This will run the script and cause the primary dialog to open up.

Click "OK" to call the file-chooser operator from the primary dialog operator.

Demo Blender File (should open in 2.79b and 2.80):
2019_06_04_file_chooser_bug_b2_79.blend

Demo Code (for both 2.79 and 2.80):

import bpy
from bpy.types import Operator
from bpy_extras.io_utils import ImportHelper
from bpy.utils import register_class, unregister_class

- This operator shows a simple confirmation dialog that will
- invoke the operator that opens Blender's file chooser
class TEST_OT_primary_dialog(Operator):
    bl_idname = "test.primary_dialog"
    bl_label = "Primary Dialog"
    
    def draw(self, context):
        layout = self.layout
        layout.label(text="Open the file chooser?")
    
    def execute(self, context):
        
        - Both of these operator calls will cause the same behavior
        - despite using different methods.
        
        bpy.ops.test.invoke_file_chooser_1('INVOKE_DEFAULT')
        # bpy.ops.test.invoke_file_chooser_2('INVOKE_DEFAULT')    
        
        return {'FINISHED'}
     
    def invoke(self, context, event):
        wm = context.window_manager
        return wm.invoke_props_dialog(self)


- This operator will open Blender's file chooser when invoked
- and store the selected filepath in self.filepath and print it
# to the console using window_manager.fileselect_add()
class TEST_OT_invoke_file_chooser_1(Operator):
    bl_idname = "test.invoke_file_chooser_1"
    bl_label = "Submission Text 1"

    filepath = bpy.props.StringProperty(subtype='DIR_PATH')

    def execute(self, context):
        print(self.filepath)
        return {'FINISHED'}

    def invoke(self, context, event):
        context.window_manager.fileselect_add(self)
        return {'RUNNING_MODAL'}
    
    
- This operator will open Blender's file chooser when invoked
- and store the selected filepath in self.filepath and print it
# to the console using bpy_extra's ImportHelper
class TEST_OT_invoke_file_chooser_2(Operator, ImportHelper):
    bl_idname = "test.invoke_file_chooser_2"
    bl_label = "Submission Text 2"
    
    def execute(self, context):
        print(self.filepath)
        return {'FINISHED'}


# Register classes
register_class(TEST_OT_primary_dialog)
register_class(TEST_OT_invoke_file_chooser_1)
register_class(TEST_OT_invoke_file_chooser_2)


# Call the primary dialog operator
bpy.ops.test.primary_dialog('INVOKE_DEFAULT')

**System Information** Operating system: Windows 10 Pro Graphics card: (2x) NVIDIA GeForce GTX 1070 **Blender Version** Broken: 2.80, c13e10a7404d, 2019-06-04 Worked: 2.79b, f4dc9f9d68b, 2018-03-22 **Short description of error** Creating a Python script that opens Blender's file chooser from a dialog will cause Blender to crash. For ease of reproduction and demonstration, I have included a Blender file that contains a short Python script that causes this issue. The script is supposed to do the following once it is run: - Display a confirmation dialog asking the user if they would like to open a file chooser - Upon confirmation, open the file chooser. # Upon file selection, print the file's filepath to the console. ![image.png](https://archive.blender.org/developer/F7087879/image.png) This code does functions properly in Blender 2.79b (hash mentioned above), but it causes a crash in Blender 2.80. For some reason, using the execute function of the primary dialog operator, *TEST_OT_primary_dialog*, to call either of the file-chooser invoking operators, *TEST_OT_invoke_file_chooser_1* or *TEST_OT_invoke_file_chooser_2*, causes Blender 2.80 to crash. **Exact steps for others to reproduce the error** - Download and open the Blender file from below. It is a 2.79b file, but should open in 2.80 as well. - Click the "Run Script" button in the text editor. This will run the script and cause the primary dialog to open up. # Click "OK" to call the file-chooser operator from the primary dialog operator. Demo Blender File (should open in 2.79b and 2.80): [2019_06_04_file_chooser_bug_b2_79.blend](https://archive.blender.org/developer/F7087891/2019_06_04_file_chooser_bug_b2_79.blend) Demo Code (for both 2.79 and 2.80): ``` import bpy from bpy.types import Operator from bpy_extras.io_utils import ImportHelper from bpy.utils import register_class, unregister_class - This operator shows a simple confirmation dialog that will - invoke the operator that opens Blender's file chooser class TEST_OT_primary_dialog(Operator): bl_idname = "test.primary_dialog" bl_label = "Primary Dialog" def draw(self, context): layout = self.layout layout.label(text="Open the file chooser?") def execute(self, context): - Both of these operator calls will cause the same behavior - despite using different methods. bpy.ops.test.invoke_file_chooser_1('INVOKE_DEFAULT') # bpy.ops.test.invoke_file_chooser_2('INVOKE_DEFAULT') return {'FINISHED'} def invoke(self, context, event): wm = context.window_manager return wm.invoke_props_dialog(self) - This operator will open Blender's file chooser when invoked - and store the selected filepath in self.filepath and print it # to the console using window_manager.fileselect_add() class TEST_OT_invoke_file_chooser_1(Operator): bl_idname = "test.invoke_file_chooser_1" bl_label = "Submission Text 1" filepath = bpy.props.StringProperty(subtype='DIR_PATH') def execute(self, context): print(self.filepath) return {'FINISHED'} def invoke(self, context, event): context.window_manager.fileselect_add(self) return {'RUNNING_MODAL'} - This operator will open Blender's file chooser when invoked - and store the selected filepath in self.filepath and print it # to the console using bpy_extra's ImportHelper class TEST_OT_invoke_file_chooser_2(Operator, ImportHelper): bl_idname = "test.invoke_file_chooser_2" bl_label = "Submission Text 2" def execute(self, context): print(self.filepath) return {'FINISHED'} # Register classes register_class(TEST_OT_primary_dialog) register_class(TEST_OT_invoke_file_chooser_1) register_class(TEST_OT_invoke_file_chooser_2) # Call the primary dialog operator bpy.ops.test.primary_dialog('INVOKE_DEFAULT') ```

Grant Wilk commented

2019-06-05 06:45:44 +02:00

Added subscriber: @remi_creative

Grant Wilk changed title from ~~Opening Blender's File Chooser from Another Dialog Causes Blender to Crash~~ to Opening Blender's File Chooser from a Dialog Causes Blender to Crash

2019-06-05 07:01:18 +02:00

Jacques Lucke commented

2019-06-05 11:03:26 +02:00

Added subscribers: @ideasman42, @JacquesLucke

Jacques Lucke commented

2019-06-05 11:03:26 +02:00

The problem is probably that opening the file browser will close all popup dialogs.
Later, when the dialog tries to close itself, it does not exist anymore and it crashes.

Noticed that when I implemented the File Close Dialog (see wm_block_file_close_discard in 5ce3f69).

I see two possible solutions:

Close the dialog before executing the callback.
Don't close dialogs when the file browser opens. Maybe hide them?

Not sure what is preferable.

The problem is probably that opening the file browser will close all popup dialogs. Later, when the dialog tries to close itself, it does not exist anymore and it crashes. Noticed that when I implemented the File Close Dialog (see `wm_block_file_close_discard` in 5ce3f69). I see two possible solutions: 1. Close the dialog before executing the callback. 2. Don't close dialogs when the file browser opens. Maybe hide them? Not sure what is preferable.

Grant Wilk commented

2019-08-12 19:53:17 +02:00

I just tested this issue again in the 2.80 release and it appears to be working now.
I'm not going to close the issue myself because I don't know if you guys have some sort of confirmation protocol, but I thought I'd update the thread!

I just tested this issue again in the 2.80 release and it appears to be working now. I'm not going to close the issue myself because I don't know if you guys have some sort of confirmation protocol, but I thought I'd update the thread!

Julian Eisel commented

2019-09-09 10:56:47 +02:00

Added subscriber: @JulianEisel