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, 31 insertions, 2 deletions

diff --git a/source/blender/editors/space_outliner/outliner_tools.c b/source/blender/editors/space_outliner/outliner_tools.c
index 9af2ba6a82b..d9641930134 100644
--- a/source/blender/editors/space_outliner/outliner_tools.c
+++ b/source/blender/editors/space_outliner/outliner_tools.c
@@ -776,6 +776,11 @@ static void object_proxy_to_override_convert_fn(bContext *C,
 
 typedef struct OutlinerLibOverrideData {
   bool do_hierarchy;
+  /**
+   * For resync operation, force keeping newly created override IDs (or original linked IDs)
+   * instead of re-applying relevant existing ID pointer property override operations. Helps
+   * solving broken overrides while not losing *all* of your overrides. */
+  bool do_resync_hierarchy_enforce;
 } OutlinerLibOverrideData;
 
 static void id_override_library_create_fn(bContext *C,
@@ -872,10 +877,12 @@ static void id_override_library_resync_fn(bContext *C,
                                           TreeElement *te,
                                           TreeStoreElem *UNUSED(tsep),
                                           TreeStoreElem *tselem,
-                                          void *UNUSED(user_data))
+                                          void *user_data)
 {
   BLI_assert(TSE_IS_REAL_ID(tselem));
   ID *id_root = tselem->id;
+  OutlinerLibOverrideData *data = user_data;
+  const bool do_hierarchy_enforce = data->do_resync_hierarchy_enforce;
 
   if (ID_IS_OVERRIDE_LIBRARY_REAL(id_root)) {
     Main *bmain = CTX_data_main(C);
@@ -893,7 +900,8 @@ static void id_override_library_resync_fn(bContext *C,
       te->store_elem->id->tag |= LIB_TAG_DOIT;
     }
 
-    BKE_lib_override_library_resync(bmain, scene, CTX_data_view_layer(C), id_root);
+    BKE_lib_override_library_resync(
+        bmain, scene, CTX_data_view_layer(C), id_root, do_hierarchy_enforce);
 
     WM_event_add_notifier(C, NC_WINDOW, NULL);
   }
@@ -1710,6 +1718,7 @@ typedef enum eOutlinerIdOpTypes {
   OUTLINER_IDOP_OVERRIDE_LIBRARY_RESET,
   OUTLINER_IDOP_OVERRIDE_LIBRARY_RESET_HIERARCHY,
   OUTLINER_IDOP_OVERRIDE_LIBRARY_RESYNC_HIERARCHY,
+  OUTLINER_IDOP_OVERRIDE_LIBRARY_RESYNC_HIERARCHY_ENFORCE,
   OUTLINER_IDOP_OVERRIDE_LIBRARY_DELETE_HIERARCHY,
   OUTLINER_IDOP_SINGLE,
   OUTLINER_IDOP_DELETE,
@@ -1770,6 +1779,13 @@ static const EnumPropertyItem prop_id_op_types[] = {
      "Resync Library Override Hierarchy",
      "Rebuild this local override from its linked reference, as well as its hierarchy of "
      "dependencies"},
+    {OUTLINER_IDOP_OVERRIDE_LIBRARY_RESYNC_HIERARCHY_ENFORCE,
+     "OVERRIDE_LIBRARY_RESYNC_HIERARCHY_ENFORCE",
+     0,
+     "Resync Library Override Hierarchy Enforce",
+     "Rebuild this local override from its linked reference, as well as its hierarchy of "
+     "dependencies, enforcing that hierarchy to match the linked data (i.e. ignoring exiting "
+     "overrides on data-blocks pointer properties)"},
     {OUTLINER_IDOP_OVERRIDE_LIBRARY_DELETE_HIERARCHY,
      "OVERRIDE_LIBRARY_DELETE_HIERARCHY",
      0,
@@ -1831,6 +1847,7 @@ static bool outliner_id_operation_item_poll(bContext *C,
     case OUTLINER_IDOP_OVERRIDE_LIBRARY_RESET:
     case OUTLINER_IDOP_OVERRIDE_LIBRARY_RESET_HIERARCHY:
     case OUTLINER_IDOP_OVERRIDE_LIBRARY_RESYNC_HIERARCHY:
+    case OUTLINER_IDOP_OVERRIDE_LIBRARY_RESYNC_HIERARCHY_ENFORCE:
     case OUTLINER_IDOP_OVERRIDE_LIBRARY_DELETE_HIERARCHY:
       if (ID_IS_OVERRIDE_LIBRARY_REAL(tselem->id)) {
         return true;
@@ -2041,6 +2058,18 @@ static int outliner_id_operation_exec(bContext *C, wmOperator *op)
       ED_undo_push(C, "Resync Overridden Data Hierarchy");
       break;
     }
+    case OUTLINER_IDOP_OVERRIDE_LIBRARY_RESYNC_HIERARCHY_ENFORCE: {
+      outliner_do_libdata_operation(
+          C,
+          op->reports,
+          scene,
+          space_outliner,
+          &space_outliner->tree,
+          id_override_library_resync_fn,
+          &(OutlinerLibOverrideData){.do_hierarchy = true, .do_resync_hierarchy_enforce = true});
+      ED_undo_push(C, "Resync Overridden Data Hierarchy");
+      break;
+    }
     case OUTLINER_IDOP_OVERRIDE_LIBRARY_DELETE_HIERARCHY: {
       outliner_do_libdata_operation(C,
                                     op->reports,