Fix Buttons context, invalid object data access

Another instance of T44376.
Crash where the Python context would access a stale pointer to the active object.

1 files changed, 28 insertions, 0 deletions

diff --git a/source/blender/editors/space_node/node_edit.c b/source/blender/editors/space_node/node_edit.c
index 360087d77c7..ffd51bcc44e 100644
--- a/source/blender/editors/space_node/node_edit.c
+++ b/source/blender/editors/space_node/node_edit.c
@@ -740,6 +740,34 @@ void ED_node_set_active(Main *bmain, bNodeTree *ntree, bNode *node)
 	}
 }
 
+void ED_node_id_unref(SpaceNode *snode, const ID *id)
+{
+	if (GS(id->name) == ID_SCE) {
+		if (snode->id == id) {
+			/* nasty DNA logic for SpaceNode:
+			 * ideally should be handled by editor code, but would be bad level call
+			 */
+			bNodeTreePath *path, *path_next;
+			for (path = snode->treepath.first; path; path = path_next) {
+				path_next = path->next;
+				MEM_freeN(path);
+			}
+			BLI_listbase_clear(&snode->treepath);
+
+			snode->id = NULL;
+			snode->from = NULL;
+			snode->nodetree = NULL;
+			snode->edittree = NULL;
+		}
+	}
+	else if (GS(id->name) == ID_OB) {
+		if (snode->from == id) {
+			snode->flag &= ~SNODE_PIN;
+			snode->from = NULL;
+		}
+	}
+}
+
 void ED_node_post_apply_transform(bContext *UNUSED(C), bNodeTree *UNUSED(ntree))
 {
 	/* XXX This does not work due to layout functions relying on node->block,