Fix possibility to add objects in override collections.

Override collections do not support that, add proper checks in BKE code
adding objects to collections.

Also try to find a suitable collection in parents in that case.

Note that this is enforced on 'public' API level, internal code can
still bypass those checks if needed. Exposing this possibility to public
API should not be needed.

1 files changed, 36 insertions, 1 deletions

diff --git a/source/blender/blenkernel/intern/collection.c b/source/blender/blenkernel/intern/collection.c
index 290b181f172..a9d3c7c1b65 100644
--- a/source/blender/blenkernel/intern/collection.c
+++ b/source/blender/blenkernel/intern/collection.c
@@ -716,6 +716,31 @@ static void collection_tag_update_parent_recursive(Main *bmain,
   }
 }
 
+static Collection *collection_parent_editable_find_recursive(Collection *collection)
+{
+  if (!ID_IS_LINKED(collection) && !ID_IS_OVERRIDE_LIBRARY(collection)) {
+    return collection;
+  }
+
+  if (collection->flag & COLLECTION_IS_MASTER) {
+    return NULL;
+  }
+
+  LISTBASE_FOREACH (CollectionParent *, collection_parent, &collection->parents) {
+    if (!ID_IS_LINKED(collection_parent->collection) &&
+        !ID_IS_OVERRIDE_LIBRARY(collection_parent->collection)) {
+      return collection_parent->collection;
+    }
+    Collection *editable_collection = collection_parent_editable_find_recursive(
+        collection_parent->collection);
+    if (editable_collection != NULL) {
+      return editable_collection;
+    }
+  }
+
+  return NULL;
+}
+
 static bool collection_object_add(
     Main *bmain, Collection *collection, Object *ob, int flag, const bool add_us)
 {
@@ -786,6 +811,15 @@ bool BKE_collection_object_add(Main *bmain, Collection *collection, Object *ob)
     return false;
   }
 
+  collection = collection_parent_editable_find_recursive(collection);
+
+  /* Only case where this pointer can be NULL is when scene itself is linked, this case should
+   * never be reached. */
+  BLI_assert(collection != NULL);
+  if (collection == NULL) {
+    return false;
+  }
+
   if (!collection_object_add(bmain, collection, ob, 0, true)) {
     return false;
   }
@@ -808,7 +842,8 @@ void BKE_collection_object_add_from(Main *bmain, Scene *scene, Object *ob_src, O
   bool is_instantiated = false;
 
   FOREACH_SCENE_COLLECTION_BEGIN (scene, collection) {
-    if (!ID_IS_LINKED(collection) && BKE_collection_has_object(collection, ob_src)) {
+    if (!ID_IS_LINKED(collection) && !ID_IS_OVERRIDE_LIBRARY(collection) &&
+        BKE_collection_has_object(collection, ob_src)) {
       collection_object_add(bmain, collection, ob_dst, 0, true);
       is_instantiated = true;
     }