3 files changed, 23 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/layer.c b/source/blender/blenkernel/intern/layer.c
index f3c0d5da6ee..4198e6ded9c 100644
--- a/source/blender/blenkernel/intern/layer.c
+++ b/source/blender/blenkernel/intern/layer.c
@@ -32,6 +32,7 @@
 #include "BKE_freestyle.h"
 #include "BKE_idprop.h"
 #include "BKE_layer.h"
+#include "BKE_library.h"
 #include "BKE_main.h"
 #include "BKE_node.h"
 #include "BKE_object.h"
@@ -698,6 +699,10 @@ static short layer_collection_sync(ViewLayer *view_layer,
       lc->flag = parent_exclude;
     }
 
+    /* Tag linked collection as a weak reference so we keep the layer
+     * collection pointer on file load and remember exclude state. */
+    id_lib_indirect_weak_link(&collection->id);
+
     /* Collection restrict is inherited. */
     short child_restrict = parent_restrict;
     short child_layer_restrict = parent_layer_restrict;
@@ -735,6 +740,10 @@ static short layer_collection_sync(ViewLayer *view_layer,
         continue;
       }
 
+      /* Tag linked object as a weak reference so we keep the object
+       * base pointer on file load and remember hidden state. */
+      id_lib_indirect_weak_link(&cob->ob->id);
+
       void **base_p;
       Base *base;
       if (BLI_ghash_ensure_p(view_layer->object_bases_hash, cob->ob, &base_p)) {
diff --git a/source/blender/blenkernel/intern/library.c b/source/blender/blenkernel/intern/library.c
index 367c2fbbdda..468d0e97ece 100644
--- a/source/blender/blenkernel/intern/library.c
+++ b/source/blender/blenkernel/intern/library.c
@@ -165,12 +165,23 @@ void id_lib_extern(ID *id)
     BLI_assert(BKE_idcode_is_linkable(GS(id->name)));
     if (id->tag & LIB_TAG_INDIRECT) {
       id->tag &= ~LIB_TAG_INDIRECT;
+      id->flag &= ~LIB_INDIRECT_WEAK_LINK;
       id->tag |= LIB_TAG_EXTERN;
       id->lib->parent = NULL;
     }
   }
 }
 
+void id_lib_indirect_weak_link(ID *id)
+{
+  if (id && ID_IS_LINKED(id)) {
+    BLI_assert(BKE_idcode_is_linkable(GS(id->name)));
+    if (id->tag & LIB_TAG_INDIRECT) {
+      id->flag |= LIB_INDIRECT_WEAK_LINK;
+    }
+  }
+}
+
 /**
  * Ensure we have a real user
  *
@@ -1768,6 +1779,7 @@ void id_clear_lib_data_ex(Main *bmain, ID *id, const bool id_in_mainlist)
 
   id->lib = NULL;
   id->tag &= ~(LIB_TAG_INDIRECT | LIB_TAG_EXTERN);
+  id->flag &= ~LIB_INDIRECT_WEAK_LINK;
   if (id_in_mainlist) {
     if (BKE_id_new_name_validate(which_libbase(bmain, GS(id->name)), id, NULL)) {
       bmain->is_memfile_undo_written = false;
@@ -1981,6 +1993,7 @@ void BKE_library_make_local(Main *bmain,
 
       if (id->lib == NULL) {
         id->tag &= ~(LIB_TAG_EXTERN | LIB_TAG_INDIRECT | LIB_TAG_NEW);
+        id->flag &= ~LIB_INDIRECT_WEAK_LINK;
       }
       /* The check on the fourth line (LIB_TAG_PRE_EXISTING) is done so it's possible to tag data
        * you don't want to be made local, used for appending data,
diff --git a/source/blender/blenkernel/intern/library_remap.c b/source/blender/blenkernel/intern/library_remap.c
index 7554dad5fb0..45dbb4b6ec1 100644
--- a/source/blender/blenkernel/intern/library_remap.c
+++ b/source/blender/blenkernel/intern/library_remap.c
@@ -497,6 +497,7 @@ static void libblock_remap_data(
   if (new_id && (new_id->tag & LIB_TAG_INDIRECT) &&
       (r_id_remap_data->status & ID_REMAP_IS_LINKED_DIRECT)) {
     new_id->tag &= ~LIB_TAG_INDIRECT;
+    new_id->flag &= ~LIB_INDIRECT_WEAK_LINK;
     new_id->tag |= LIB_TAG_EXTERN;
   }