Fix (unreported) crash in outliner after recent changes to ID management core code.

Outliner tree building code abuse the `ID.newid` pointer to store non-ID
data. While this is bad and should be fixed at some point, for the time
being at the very least do not use ID BKE API to deal with this pointer
in that specific case, this needs its own proper code.

1 files changed, 12 insertions, 1 deletions

diff --git a/source/blender/editors/space_outliner/outliner_tree.c b/source/blender/editors/space_outliner/outliner_tree.c
index c5ec656080a..5427ae31ac3 100644
--- a/source/blender/editors/space_outliner/outliner_tree.c
+++ b/source/blender/editors/space_outliner/outliner_tree.c
@@ -1864,6 +1864,15 @@ static void outliner_filter_tree(SpaceOutliner *space_outliner, ViewLayer *view_
       space_outliner, view_layer, &space_outliner->tree, search_string, exclude_filter);
 }
 
+static void outliner_clear_newid_from_main(Main *bmain)
+{
+  ID *id_iter;
+  FOREACH_MAIN_ID_BEGIN (bmain, id_iter) {
+    id_iter->newid = NULL;
+  }
+  FOREACH_MAIN_ID_END;
+}
+
 /* ======================================================= */
 /* Main Tree Building API */
 
@@ -1926,5 +1935,7 @@ void outliner_build_tree(Main *mainvar,
   outliner_filter_tree(space_outliner, view_layer);
   outliner_restore_scrolling_position(space_outliner, region, &focus);
 
-  BKE_main_id_newptr_and_tag_clear(mainvar);
+  /* `ID.newid` pointer is abused when building tree, DO NOT call #BKE_main_id_newptr_and_tag_clear
+   * as this expects valid IDs in this pointer, not random unknown data. */
+  outliner_clear_newid_from_main(mainvar);
 }