Fix T38260: Missing object update with two visible scenes

It was an issue with early object update check which was
screwing up for second scene because of first one reset
ID recalc flags.

From the comment in the code about this:

  We need to check all visible scenes, otherwise resetting
  OB_ID changed flag will only work fine for first scene of
  multiple visible and all the rest will skip update.

  This could also lead to wrong behavior scene update handlers
  because of missing ID datablock changed flags.

  This is a bit of a bummer to allocate list here, but likely
  it wouldn't become too much bad because it only happens when
  objects were actually changed.

1 files changed, 32 insertions, 8 deletions

diff --git a/source/blender/blenkernel/intern/depsgraph.c b/source/blender/blenkernel/intern/depsgraph.c
index 0f6be44a1ee..80deb354d09 100644
--- a/source/blender/blenkernel/intern/depsgraph.c
+++ b/source/blender/blenkernel/intern/depsgraph.c
@@ -2471,7 +2471,7 @@ void DAG_ids_check_recalc(Main *bmain, Scene *scene, int time)
 
 #define POST_UPDATE_HANDLER_WORKAROUND
 
-void DAG_ids_clear_recalc(Main *bmain, Scene *scene)
+void DAG_ids_clear_recalc(Main *bmain)
 {
 	ListBase *lbarray[MAX_LIBARRAY];
 	bNodeTree *ntree;
@@ -2481,16 +2481,40 @@ void DAG_ids_clear_recalc(Main *bmain, Scene *scene)
 	bool have_updated_objects = false;
 
 	if (DAG_id_type_tagged(bmain, ID_OB)) {
-		DagNode *node;
-		for (node = scene->theDag->DagNode.first; node; node = node->next) {
-			if (node->type == ID_OB) {
-				Object *object = (Object *) node->ob;
-				if (object->recalc & OB_RECALC_ALL) {
-					have_updated_objects = true;
-					break;
+		ListBase listbase;
+		DagSceneLayer *dsl;
+
+		/* We need to check all visible scenes, otherwise resetting
+		 * OB_ID changed flag will only work fine for first scene of
+		 * multiple visible and all the rest will skip update.
+		 *
+		 * This could also lead to wrong behavior scene update handlers
+		 * because of missing ID datablock changed flags.
+		 *
+		 * This is a bit of a bummer to allocate list here, but likely
+		 * it wouldn't become too much bad because it only happens when
+		 * objects were actually changed.
+		 */
+		dag_current_scene_layers(bmain, &listbase);
+
+		for (dsl = listbase.first; dsl; dsl = dsl->next) {
+			Scene *scene = dsl->scene;
+			DagNode *node;
+			for (node = scene->theDag->DagNode.first;
+			     node != NULL && have_updated_objects == false;
+			     node = node->next)
+			{
+				if (node->type == ID_OB) {
+					Object *object = (Object *) node->ob;
+					if (object->recalc & OB_RECALC_ALL) {
+						have_updated_objects = true;
+						break;
+					}
 				}
 			}
 		}
+
+		BLI_freelistN(&listbase);
 	}
 #else
 	(void) scene;  /* Unused. */