Fix T80457: Library Override - Custom Property to Drive Child Particles results in Crash.

RNA diffing code was not dealing properly valid NULL PointerRNA (like
the empty texture slots of a ParticleSettings e.g., which were cause of
crash in that report).

To be backported to 2.90 and 2.83.

1 files changed, 6 insertions, 3 deletions

diff --git a/source/blender/makesrna/intern/rna_rna.c b/source/blender/makesrna/intern/rna_rna.c
index 4ee144e9031..96e6980aa1d 100644
--- a/source/blender/makesrna/intern/rna_rna.c
+++ b/source/blender/makesrna/intern/rna_rna.c
@@ -1186,9 +1186,12 @@ static bool rna_property_override_diff_propptr_validate_diffing(PointerRNA *prop
    * This helps a lot in library override case, especially to detect inserted items in collections.
    */
   if (!no_prop_name && (is_valid_for_diffing || do_force_name)) {
-    PropertyRNA *nameprop_a = RNA_struct_name_property(propptr_a->type);
-    PropertyRNA *nameprop_b = (propptr_b != NULL) ? RNA_struct_name_property(propptr_b->type) :
-                                                    NULL;
+    PropertyRNA *nameprop_a = (propptr_a->type != NULL) ?
+                                  RNA_struct_name_property(propptr_a->type) :
+                                  NULL;
+    PropertyRNA *nameprop_b = (propptr_b != NULL && propptr_b->type != NULL) ?
+                                  RNA_struct_name_property(propptr_b->type) :
+                                  NULL;
 
     int propname_a_len = 0, propname_b_len = 0;
     char *propname_a = NULL;