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, 0 deletions

diff --git a/source/blender/blenkernel/intern/lib_remap.c b/source/blender/blenkernel/intern/lib_remap.c
index 9ea85714b4a..b8e0eb2c942 100644
--- a/source/blender/blenkernel/intern/lib_remap.c
+++ b/source/blender/blenkernel/intern/lib_remap.c
@@ -282,6 +282,11 @@ static void libblock_remap_data_postprocess_object_update(Main *bmain,
      * to remove the NULL children from collections not used in any scene. */
     BKE_collections_object_remove_nulls(bmain);
   }
+  else {
+    /* Remapping may have created duplicates of CollectionObject pointing to the same object within
+     * the same collection. */
+    BKE_collections_object_remove_duplicates(bmain);
+  }
 
   BKE_main_collection_sync_remap(bmain);
 
@@ -319,6 +324,7 @@ static void libblock_remap_data_postprocess_collection_update(Main *bmain,
   else {
     /* Temp safe fix, but a "tad" brute force... We should probably be able to use parents from
      * old_collection instead? */
+    /* NOTE: Also takes care of duplicated child collections that remapping may have created. */
     BKE_main_collections_parent_relations_rebuild(bmain);
   }