very long operator name crashes upon addon activation #70000

System Information
Operating system: Darwin-16.7.0-x86_64-i386-64bit 64 Bits
Graphics card:

Blender Version
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: f6cb5f5449
Worked: (optional)

Short description of error
very long operator name crashes upon addon activation

Exact steps for others to reproduce the error
install example addon, try to enable in preferences

example.py

Added subscriber: @JakubUhlik

Added subscribers: @ideasman42, @BrendonMurphy

@ideasman42 this seems a little like a forced error, users should not do this nor expect it to work. It deliberately defies pep8 just to prove a point.
Unfortunately it's a real thing I guess, so users should be prevented from taking this action?

Added subscriber: @JacquesLucke

Changed status from 'Open' to: 'Resolved'

I get the following error message:

Traceback (most recent call last):
  File "/Text", line 31, in <module>
  File "/Text", line 22, in register
RuntimeError: Error: Registering operator class: 'EXAMPLE_OT_some_quite_a_long_name_for_an_operator_to_handle_and_a_bit_more_characters_to_make_sure_it_crashes', invalid bl_idname 'example_ops.some_quite_a_long_name_for_an_operator_to_handle_an', is too long, maximum length is 61

This is a perfectly valid limitation imo (could be improved in the future, but I don't see a big benefit).
This is not a bug in Blender but in the addon.

Added subscriber: @deadpin

I get a crash here. How did you try the addon? I did a real Install from preferences and then attempted to enable it, leading to the following.

The stack based idname_bl array has been overrun:

Run-Time Check Failure #2 - Stack around the variable 'idname_bl' was corrupted.

blender.exe!WM_operatortype_find(const unsigned char * idname, bool quiet) Line 90	C
blender.exe!rna_Operator_register(Main * bmain, ReportList * reports, void * data, const unsigned char * identifier, int(*)(PointerRNA *, void *, int *) validate, int(*)(bContext *, PointerRNA *, FunctionRNA *, ParameterList *) call, void(*)(void *) free) Line 1506	C
blender.exe!pyrna_register_class(_object * UNUSED_self, _object * py_class) Line 8630	C
[External Code]	
blender.exe!bpy_class_call(bContext * C, PointerRNA * ptr, FunctionRNA * func, ParameterList * parms) Line 8313	C
blender.exe!rna_operator_execute_cb(bContext * C, wmOperator * op) Line 1299	C
blender.exe!wm_operator_invoke(bContext * C, wmOperatorType * ot, wmEvent * event, PointerRNA * properties, ReportList * reports, const bool poll_only, bool use_last_properties) Line 1451	C
blender.exe!wm_operator_call_internal(bContext * C, wmOperatorType * ot, PointerRNA * properties, ReportList * reports, const short context, const bool poll_only, wmEvent * event) Line 1652	C
blender.exe!WM_operator_name_call_ptr(bContext * C, wmOperatorType * ot, short context, PointerRNA * properties) Line 1701	C
blender.exe!ui_apply_but_funcs_after(bContext * C) Line 845	C
blender.exe!ui_handler_region_menu(bContext * C, const wmEvent * event, void * UNUSED_userdata) Line 10222	C
blender.exe!wm_handler_ui_call(bContext * C, wmEventHandler_UI * handler, const wmEvent * event, int always_pass) Line 622	C
blender.exe!wm_handlers_do_intern(bContext * C, wmEvent * event, ListBase * handlers) Line 2731	C
blender.exe!wm_handlers_do(bContext * C, wmEvent * event, ListBase * handlers) Line 2977	C
blender.exe!wm_event_do_handlers(bContext * C) Line 3356	C
blender.exe!WM_main(bContext * C) Line 420	C

I get a crash here. How did you try the addon? I did a real Install from preferences and then attempted to enable it, leading to the following. The stack based `idname_bl` array has been overrun: ``` Run-Time Check Failure #2 - Stack around the variable 'idname_bl' was corrupted. blender.exe!WM_operatortype_find(const unsigned char * idname, bool quiet) Line 90 C blender.exe!rna_Operator_register(Main * bmain, ReportList * reports, void * data, const unsigned char * identifier, int(*)(PointerRNA *, void *, int *) validate, int(*)(bContext *, PointerRNA *, FunctionRNA *, ParameterList *) call, void(*)(void *) free) Line 1506 C blender.exe!pyrna_register_class(_object * UNUSED_self, _object * py_class) Line 8630 C [External Code] blender.exe!bpy_class_call(bContext * C, PointerRNA * ptr, FunctionRNA * func, ParameterList * parms) Line 8313 C blender.exe!rna_operator_execute_cb(bContext * C, wmOperator * op) Line 1299 C blender.exe!wm_operator_invoke(bContext * C, wmOperatorType * ot, wmEvent * event, PointerRNA * properties, ReportList * reports, const bool poll_only, bool use_last_properties) Line 1451 C blender.exe!wm_operator_call_internal(bContext * C, wmOperatorType * ot, PointerRNA * properties, ReportList * reports, const short context, const bool poll_only, wmEvent * event) Line 1652 C blender.exe!WM_operator_name_call_ptr(bContext * C, wmOperatorType * ot, short context, PointerRNA * properties) Line 1701 C blender.exe!ui_apply_but_funcs_after(bContext * C) Line 845 C blender.exe!ui_handler_region_menu(bContext * C, const wmEvent * event, void * UNUSED_userdata) Line 10222 C blender.exe!wm_handler_ui_call(bContext * C, wmEventHandler_UI * handler, const wmEvent * event, int always_pass) Line 622 C blender.exe!wm_handlers_do_intern(bContext * C, wmEvent * event, ListBase * handlers) Line 2731 C blender.exe!wm_handlers_do(bContext * C, wmEvent * event, ListBase * handlers) Line 2977 C blender.exe!wm_event_do_handlers(bContext * C) Line 3356 C blender.exe!WM_main(bContext * C) Line 420 C ```

I can reproduce the crash when the addon is loaded (I just run it in the text editor).
While this can be considered a security issue in Blender (due to the buffer overflow), we generally cannot avoid security issues when people run arbitrary Python code.

Addons resulting in a crash, because they use the Python API incorrectly, is generally not considered to be a bug in Blender.

Fixed the crash 4e9aadac5e

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very long operator name crashes upon addon activation #70000