Fix T79633: ovrride apply code broken with RNA-defined runtime IDProps in some cases.

When copying between a set RNA runtime property and an unset one, code
would not behave properly.

We have to also consider NULL 'override apply' callback pointer as a
valid 'use default override apply function' case.

1 files changed, 2 insertions, 2 deletions

diff --git a/source/blender/makesrna/intern/rna_access_compare_override.c b/source/blender/makesrna/intern/rna_access_compare_override.c
index 0a739dcfc5a..ac4553349cc 100644
--- a/source/blender/makesrna/intern/rna_access_compare_override.c
+++ b/source/blender/makesrna/intern/rna_access_compare_override.c
@@ -484,13 +484,13 @@ static bool rna_property_override_operation_apply(Main *bmain,
   /* Special case for IDProps, we use default callback then. */
   if (prop_dst->magic != RNA_MAGIC) {
     override_apply = rna_property_override_apply_default;
-    if (prop_src->magic == RNA_MAGIC && prop_src->override_apply != override_apply) {
+    if (prop_src->magic == RNA_MAGIC && !ELEM(prop_src->override_apply, NULL, override_apply)) {
       override_apply = NULL;
     }
   }
   else if (prop_src->magic != RNA_MAGIC) {
     override_apply = rna_property_override_apply_default;
-    if (prop_dst->override_apply != override_apply) {
+    if (!ELEM(prop_dst->override_apply, NULL, override_apply)) {
       override_apply = NULL;
     }
   }