Fix T93799: Outliner: Remaping objects could result in duplicates in a collection.

Fix is similar to how CollectionObject with NULL object pointers are handled.

Using one of the 'free' pad bytes in Object_Runtime struct instead of a
gset (or other external way to detect object duplicates), as this is
several times faster.

NOTE: This makes remapping slightly slower again (adds 10 extra seconds
to file case in T94059).

General improvements of remapping time complexity, especially when
remapping a lot of IDs at once, is a separate topic currently
investigated in D13615.

1 files changed, 6 insertions, 1 deletions

diff --git a/source/blender/makesdna/DNA_object_types.h b/source/blender/makesdna/DNA_object_types.h
index c9345b6a950..13a368e4263 100644
--- a/source/blender/makesdna/DNA_object_types.h
+++ b/source/blender/makesdna/DNA_object_types.h
@@ -126,7 +126,12 @@ typedef struct Object_Runtime {
   /** Did last modifier stack generation need mapping support? */
   char last_need_mapping;
 
-  char _pad0[3];
+  /** Opaque data reserved for management of objects in collection context.
+   *  E.g. used currently to check for potential duplicates of objects in a collection, after
+   * remapping process. */
+  char collection_management;
+
+  char _pad0[2];
 
   /** Only used for drawing the parent/child help-line. */
   float parent_display_origin[3];