LibOverride: only tag actually changed orig IDs for automatic override diffing.

This makes any operation (including mere bone selection) several times
faster on some complex production character, since we typically now only
need to diff a single ID, instead of tens of them.

1 files changed, 4 insertions, 1 deletions

diff --git a/source/blender/depsgraph/intern/eval/deg_eval_flush.cc b/source/blender/depsgraph/intern/eval/deg_eval_flush.cc
index df6c139e916..50469d57a34 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_flush.cc
+++ b/source/blender/depsgraph/intern/eval/deg_eval_flush.cc
@@ -251,7 +251,10 @@ void flush_editors_id_update(Depsgraph *graph, const DEGEditorUpdateContext *upd
       if (graph->is_active && id_node->is_user_modified) {
         deg_editors_id_update(update_ctx, id_orig);
       }
-      if (ID_IS_OVERRIDE_LIBRARY(id_orig)) {
+      if (ID_IS_OVERRIDE_LIBRARY(id_orig) && id_orig->recalc != 0) {
+        /* We only want to tag an ID for liboverride autorefresh if it was actually tagged as
+         * changed. CoW IDs indirectly modified because of changes in other IDs should never
+         * require a liboverride diffing. */
         id_orig->tag |= LIB_TAG_OVERRIDE_LIBRARY_AUTOREFRESH;
       }
       /* Inform draw engines that something was changed. */