Fix T86332: Error using lambda in annotations in Python 3.10

Callbacks used in `bpy.props` didn't hold a references to the functions
they used.

While this has been the case since early 2.5x it didn't cause any
problems as long as the class held a reference.

With Python 3.10 or when using `from __future__ import annotations`,
the annotations are no longer owned by the class once evaluated.

Resolve this by holding a reference in the module, which now supports
traverse & clear callbacks so the objects are visible to Python's
garbage collector.

Also refactor storage of Python data, moving from an array into a struct.

1 files changed, 0 insertions, 1 deletions

diff --git a/source/blender/makesrna/intern/rna_internal_types.h b/source/blender/makesrna/intern/rna_internal_types.h
index 1dd08bb1074..0c0260c889c 100644
--- a/source/blender/makesrna/intern/rna_internal_types.h
+++ b/source/blender/makesrna/intern/rna_internal_types.h
@@ -457,7 +457,6 @@ typedef struct EnumPropertyRNA {
 
   PropEnumGetFuncEx get_ex;
   PropEnumSetFuncEx set_ex;
-  void *py_data; /* store py callback here */
 
   const EnumPropertyItem *item;
   int totitem;