LibOverride: Add 'delete and use linked data' operation.

This will re-link all usages of a library override data-block
(including all of its override dependencies) to its reference linked
IDs, and delete those liboverrides.

As usual, it is available in the ID sub-menu of the outliner context
right-click menu.

Part of T76555.

3 files changed, 98 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_lib_override.h b/source/blender/blenkernel/BKE_lib_override.h
index 7b10ed4d43c..9a5700d2fbd 100644
--- a/source/blender/blenkernel/BKE_lib_override.h
+++ b/source/blender/blenkernel/BKE_lib_override.h
@@ -81,6 +81,7 @@ bool BKE_lib_override_library_resync(struct Main *bmain,
                                      struct Scene *scene,
                                      struct ViewLayer *view_layer,
                                      struct ID *id_root);
+void BKE_lib_override_library_delete(struct Main *bmain, struct ID *id_root);
 
 struct IDOverrideLibraryProperty *BKE_lib_override_library_property_find(
     struct IDOverrideLibrary *override, const char *rna_path);
diff --git a/source/blender/blenkernel/intern/lib_override.c b/source/blender/blenkernel/intern/lib_override.c
index b4f0905f042..cca312270bc 100644
--- a/source/blender/blenkernel/intern/lib_override.c
+++ b/source/blender/blenkernel/intern/lib_override.c
@@ -784,6 +784,50 @@ bool BKE_lib_override_library_resync(Main *bmain, Scene *scene, ViewLayer *view_
   return success;
 }
 
+/**
+ * Advanced 'smart' function to delete library overrides (including their existing override
+ * hierarchy) and remap their usages to their linked reference IDs.
+ *
+ * \note All IDs tagged with `LIB_TAG_DOIT` will be deleted.
+ *
+ * \param id_root The root liboverride ID to resync from.
+ */
+void BKE_lib_override_library_delete(Main *bmain, ID *id_root)
+{
+  BLI_assert(ID_IS_OVERRIDE_LIBRARY_REAL(id_root));
+
+  /* Tag all collections and objects, as well as other IDs using them. */
+  id_root->tag |= LIB_TAG_DOIT;
+
+  /* Make a mapping 'linked reference IDs' -> 'Local override IDs' of existing overrides, and tag
+   * linked reference ones to be overridden again. */
+  BKE_lib_override_library_override_group_tag(bmain, id_root, LIB_TAG_DOIT, true);
+
+  ID *id;
+  FOREACH_MAIN_ID_BEGIN (bmain, id) {
+    if (id->tag & LIB_TAG_DOIT) {
+      if (ID_IS_OVERRIDE_LIBRARY_REAL(id)) {
+        ID *id_override_reference = id->override_library->reference;
+
+        /* Remap the whole local IDs to use the linked data. */
+        BKE_libblock_remap(bmain, id, id_override_reference, ID_REMAP_SKIP_INDIRECT_USAGE);
+      }
+    }
+  }
+  FOREACH_MAIN_ID_END;
+
+  /* Delete the override IDs. */
+  FOREACH_MAIN_ID_BEGIN (bmain, id) {
+    if (id->tag & LIB_TAG_DOIT) {
+      BKE_id_delete(bmain, id);
+    }
+  }
+  FOREACH_MAIN_ID_END;
+
+  /* Should not actually be needed here... */
+  BKE_main_id_tag_all(bmain, LIB_TAG_DOIT, false);
+}
+
 BLI_INLINE IDOverrideLibraryRuntime *override_library_rna_path_runtime_ensure(
     IDOverrideLibrary *override)
 {
diff --git a/source/blender/editors/space_outliner/outliner_tools.c b/source/blender/editors/space_outliner/outliner_tools.c
index 4eed824207e..b2106698054 100644
--- a/source/blender/editors/space_outliner/outliner_tools.c
+++ b/source/blender/editors/space_outliner/outliner_tools.c
@@ -860,6 +860,38 @@ static void id_override_library_resync_fn(bContext *C,
   }
 }
 
+static void id_override_library_delete_fn(bContext *C,
+                                          ReportList *UNUSED(reports),
+                                          Scene *UNUSED(scene),
+                                          TreeElement *te,
+                                          TreeStoreElem *UNUSED(tsep),
+                                          TreeStoreElem *tselem,
+                                          void *UNUSED(user_data))
+{
+  BLI_assert(TSE_IS_REAL_ID(tselem));
+  ID *id_root = tselem->id;
+
+  if (ID_IS_OVERRIDE_LIBRARY_REAL(id_root)) {
+    Main *bmain = CTX_data_main(C);
+
+    id_root->tag |= LIB_TAG_DOIT;
+
+    /* Tag all linked parents in tree hierarchy to be also overridden. */
+    while ((te = te->parent) != NULL) {
+      if (!TSE_IS_REAL_ID(te->store_elem)) {
+        continue;
+      }
+      if (!ID_IS_OVERRIDE_LIBRARY_REAL(te->store_elem->id)) {
+        break;
+      }
+      te->store_elem->id->tag |= LIB_TAG_DOIT;
+    }
+    BKE_lib_override_library_delete(bmain, id_root);
+
+    BKE_main_id_tag_all(bmain, LIB_TAG_DOIT, false);
+  }
+}
+
 static void id_fake_user_set_fn(bContext *UNUSED(C),
                                 ReportList *UNUSED(reports),
                                 Scene *UNUSED(scene),
@@ -1641,6 +1673,7 @@ typedef enum eOutlinerIdOpTypes {
   OUTLINER_IDOP_OVERRIDE_LIBRARY_RESET,
   OUTLINER_IDOP_OVERRIDE_LIBRARY_RESET_HIERARCHY,
   OUTLINER_IDOP_OVERRIDE_LIBRARY_RESYNC_HIERARCHY,
+  OUTLINER_IDOP_OVERRIDE_LIBRARY_DELETE_HIERARCHY,
   OUTLINER_IDOP_SINGLE,
   OUTLINER_IDOP_DELETE,
   OUTLINER_IDOP_REMAP,
@@ -1693,6 +1726,12 @@ 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_DELETE_HIERARCHY,
+     "OVERRIDE_LIBRARY_DELETE_HIERARCHY",
+     0,
+     "Delete Library Override Hierarchy",
+     "Delete this local override (including its hierarchy of override dependencies) and relink "
+     "its usages to the linked data-blocks"},
     {0, "", 0, NULL, NULL},
     {OUTLINER_IDOP_COPY, "COPY", ICON_COPYDOWN, "Copy", ""},
     {OUTLINER_IDOP_PASTE, "PASTE", ICON_PASTEDOWN, "Paste", ""},
@@ -1725,6 +1764,8 @@ static bool outliner_id_operation_item_poll(bContext *C,
       return true;
     case OUTLINER_IDOP_OVERRIDE_LIBRARY_RESYNC_HIERARCHY:
       return true;
+    case OUTLINER_IDOP_OVERRIDE_LIBRARY_DELETE_HIERARCHY:
+      return true;
     case OUTLINER_IDOP_SINGLE:
       if (!space_outliner || ELEM(space_outliner->outlinevis, SO_SCENES, SO_VIEW_LAYER)) {
         return true;
@@ -1919,6 +1960,18 @@ static int outliner_id_operation_exec(bContext *C, wmOperator *op)
       ED_undo_push(C, "Resync Overridden Data Hierarchy");
       break;
     }
+    case OUTLINER_IDOP_OVERRIDE_LIBRARY_DELETE_HIERARCHY: {
+      /* make local */
+      outliner_do_libdata_operation(C,
+                                    op->reports,
+                                    scene,
+                                    space_outliner,
+                                    &space_outliner->tree,
+                                    id_override_library_delete_fn,
+                                    &(OutlinerLibOverrideData){.do_hierarchy = true});
+      ED_undo_push(C, "Delete Overridden Data Hierarchy");
+      break;
+    }
     case OUTLINER_IDOP_SINGLE: {
       /* make single user */
       switch (idlevel) {