Fix T44439: outliner's treestore could keep invalid ID pointers, could crash on undo due to invalid mem access.

We cannot nuke treestore in readfile's `blo_lib_link_screen_restore()`, because this will
destroy all UI-state data (like opened/closed items, etc.).

Since we cannot know for sure whether an ID pointer from tselem->id is valid here, we
have to ensure they are never invalid, i.e. to always set them to NULL when we delete them.

To do so, this commit uses a similar approach as what already exists for ID references
in WM notifiers - it extends `free_notifier_reference_cb()` to also nullify those IDs in
all outliners.

Note that some ID types are not used(shown) by outliner currently, so `TREESTORE_ID_TYPE` macro
was added, that checks whether an ID is possibly used by outliner. Avoids a few searches
in whole tree whene deleting some IDs.

Reviewers: campbellbarton, sergey

Maniphest Tasks: T44439

Differential Revision: https://developer.blender.org/D1272

1 files changed, 19 insertions, 0 deletions

diff --git a/source/blender/windowmanager/intern/wm_event_system.c b/source/blender/windowmanager/intern/wm_event_system.c
index e2b8598b4fe..c883b37f6c5 100644
--- a/source/blender/windowmanager/intern/wm_event_system.c
+++ b/source/blender/windowmanager/intern/wm_event_system.c
@@ -63,6 +63,7 @@
 
 #include "ED_fileselect.h"
 #include "ED_info.h"
+#include "ED_outliner.h"
 #include "ED_screen.h"
 #include "ED_view3d.h"
 #include "ED_util.h"
@@ -217,6 +218,8 @@ void WM_main_remove_notifier_reference(const void *reference)
 {
 	Main *bmain = G.main;
 	wmWindowManager *wm = bmain->wm.first;
+	bScreen *sc;
+
 	if (wm) {
 		wmNotifier *note, *note_next;
 
@@ -230,6 +233,22 @@ void WM_main_remove_notifier_reference(const void *reference)
 			}
 		}
 	}
+
+	for (sc = bmain->screen.first; sc; sc = sc->id.next) {
+		ScrArea *sa;
+
+		for (sa = sc->areabase.first; sa; sa = sa->next) {
+			SpaceLink *sl;
+
+			for (sl = sa->spacedata.first; sl; sl = sl->next) {
+				if (sl->spacetype == SPACE_OUTLINER) {
+					SpaceOops *so = (SpaceOops *)sl;
+
+					ED_outliner_id_unref(so, (ID *)reference);
+				}
+			}
+		}
+	}
 }
 
 static void wm_notifier_clear(wmNotifier *note)