LibOverride: Add a dedicated view in the Outliner.

This is a minimal, information-only view currently, listing by default
all the override data-blocks, with their user-edited override
properties.

System-generated overrides (like the overrides of pointers to other
override data-blocks) can be shown through a filter option.

Finally, potential info or warning messages from (auto-)resync propcess
are also shown, as an icon + tooltip next to the affected items.

Part of D10855.

1 files changed, 5 insertions, 0 deletions

diff --git a/source/blender/editors/space_outliner/outliner_tree.c b/source/blender/editors/space_outliner/outliner_tree.c
index 573fb492613..14ab7fd9974 100644
--- a/source/blender/editors/space_outliner/outliner_tree.c
+++ b/source/blender/editors/space_outliner/outliner_tree.c
@@ -908,6 +908,11 @@ TreeElement *outliner_add_element(SpaceOutliner *space_outliner,
       BLI_assert(!"Expected this ID type to be ported to new Outliner tree-element design");
     }
   }
+  else if (ELEM(type, TSE_LIBRARY_OVERRIDE_BASE, TSE_LIBRARY_OVERRIDE)) {
+    if (!te->type) {
+      BLI_assert(!"Expected override types to be ported to new Outliner tree-element design");
+    }
+  }
   else {
     /* Other cases must be caught above. */
     BLI_assert(TSE_IS_REAL_ID(tselem));