LibOverride: Add a new operation to Outliner to enforce resync of hierarchies.

This is basically done by ignoring override operations from old override
affecting ID pointer properties, when the new (destination) one is not
NULL.

Fix T86501: New object added to overridden collection doesn't show up in linking file on Resync.

This is more of a work-around actually, since there is no real way to
fix the issue in a fully automated and consistent way, it is caused by
older blender files being saved with 'broken' overrides.

WARNING: This cannot ensure that some purposedly edited/overridden ID
pointer properties won't be lost in the process.

1 files changed, 17 insertions, 6 deletions

diff --git a/source/blender/blenkernel/intern/lib_override.c b/source/blender/blenkernel/intern/lib_override.c
index 5100fbf08ad..223ae13cba9 100644
--- a/source/blender/blenkernel/intern/lib_override.c
+++ b/source/blender/blenkernel/intern/lib_override.c
@@ -829,7 +829,8 @@ bool BKE_lib_override_library_proxy_convert(Main *bmain,
  * \param id_root: The root liboverride ID to resync from.
  * \return true if override was successfully resynced.
  */
-bool BKE_lib_override_library_resync(Main *bmain, Scene *scene, ViewLayer *view_layer, ID *id_root)
+bool BKE_lib_override_library_resync(
+    Main *bmain, Scene *scene, ViewLayer *view_layer, ID *id_root, const bool do_hierarchy_enforce)
 {
   BLI_assert(ID_IS_OVERRIDE_LIBRARY_REAL(id_root));
 
@@ -978,8 +979,14 @@ bool BKE_lib_override_library_resync(Main *bmain, Scene *scene, ViewLayer *view_
           }
         }
 
-        RNA_struct_override_apply(
-            bmain, &rnaptr_dst, &rnaptr_src, NULL, id_override_new->override_library);
+        RNA_struct_override_apply(bmain,
+                                  &rnaptr_dst,
+                                  &rnaptr_src,
+                                  NULL,
+                                  id_override_new->override_library,
+                                  do_hierarchy_enforce ?
+                                      RNA_OVERRIDE_APPLY_FLAG_IGNORE_ID_POINTERS :
+                                      RNA_OVERRIDE_APPLY_FLAG_NOP);
       }
     }
   }
@@ -1144,7 +1151,7 @@ void BKE_lib_override_library_main_resync(Main *bmain, Scene *scene, ViewLayer *
           continue;
         }
         do_continue = true;
-        const bool success = BKE_lib_override_library_resync(bmain, scene, view_layer, id);
+        const bool success = BKE_lib_override_library_resync(bmain, scene, view_layer, id, false);
         CLOG_INFO(&LOG, 2, "Resynced %s, success: %d", id->name, success);
         break;
       }
@@ -2104,8 +2111,12 @@ void BKE_lib_override_library_update(Main *bmain, ID *local)
     RNA_id_pointer_create(local->override_library->storage, rnaptr_storage);
   }
 
-  RNA_struct_override_apply(
-      bmain, &rnaptr_dst, &rnaptr_src, rnaptr_storage, local->override_library);
+  RNA_struct_override_apply(bmain,
+                            &rnaptr_dst,
+                            &rnaptr_src,
+                            rnaptr_storage,
+                            local->override_library,
+                            RNA_OVERRIDE_APPLY_FLAG_NOP);
 
   /* This also transfers all pointers (memory) owned by local to tmp_id, and vice-versa.
    * So when we'll free tmp_id, we'll actually free old, outdated data from local. */