[Bf-blender-cvs] [0133bcaf38f] master: Fix crash starting Blender with Python 3.9

[Campbell Barton]

Commit: 0133bcaf38f6ecb5d6937c9b762026cc452720de
Author: Campbell Barton
Date:   Wed Oct 14 16:15:44 2020 +1100
Branches: master
https://developer.blender.org/rB0133bcaf38f6ecb5d6937c9b762026cc452720de

Fix crash starting Blender with Python 3.9

In 3.8 and older the class held a reference to methods,
this is no longer the case in 3.9.

===================================================================

M	source/blender/python/intern/bpy_rna.c

===================================================================

diff --git a/source/blender/python/intern/bpy_rna.c b/source/blender/python/intern/bpy_rna.c
index 7796d0a01a1..ce66cd6ee27 100644
--- a/source/blender/python/intern/bpy_rna.c
+++ b/source/blender/python/intern/bpy_rna.c
@@ -8131,9 +8131,8 @@ static int bpy_class_validate_recursive(PointerRNA *dummyptr,
       PyErr_Clear();
     }
     else {
-      /* No need to keep a ref, the class owns it
-       * (technically we should keep a reference, but...). */
-      Py_DECREF(item);
+      /* Store original so we can decrement it's reference before returning. */
+      PyObject *item_orig = item;
 
       if (is_staticmethod) {
         if (PyMethod_Check(item) == 0) {
@@ -8144,6 +8143,7 @@ static int bpy_class_validate_recursive(PointerRNA *dummyptr,
                        py_class_name,
                        RNA_function_identifier(func),
                        Py_TYPE(item)->tp_name);
+          Py_DECREF(item_orig);
           return -1;
         }
         item = ((PyMethodObject *)item)->im_func;
@@ -8157,6 +8157,7 @@ static int bpy_class_validate_recursive(PointerRNA *dummyptr,
                        py_class_name,
                        RNA_function_identifier(func),
                        Py_TYPE(item)->tp_name);
+          Py_DECREF(item_orig);
           return -1;
         }
       }
@@ -8197,9 +8198,11 @@ static int bpy_class_validate_recursive(PointerRNA *dummyptr,
                 func_arg_count,
                 arg_count);
           }
+          Py_DECREF(item_orig);
           return -1;
         }
       }
+      Py_DECREF(item_orig);
     }
   }