Fix for the "black F-Curves" bug on undo

(From personal stash of bugs - since early 2.5 versions)

F-Curve colors get applied only on Graph Editor "refresh()". In some cases, undo
was reverting back to a state where the colors had not yet been set. In these
cases, there would be no refresh() after that undo (until expanding a channel or
some other similar action), resulting in "black F-Curves" appearing. So, now we
force such an update after undo to ensure that the curves never display black.

(Noticed while investigating another bug for Mango related to
CLIP_OT_constraint_to_fcurve not sending notifiers required when new F-Curves
are added)

2 files changed, 16 insertions, 3 deletions

diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 836f723327e..7133f79f880 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -5533,6 +5533,11 @@ void lib_link_screen_restore(Main *newmain, bScreen *curscreen, Scene *curscene)
 						if (ads->filter_grp)
 							ads->filter_grp = restore_pointer_by_name(newmain, (ID *)ads->filter_grp, 0);
 					}
+					
+					/* force recalc of list of channels (i.e. includes calculating F-Curve colors)
+					 * thus preventing the "black curves" problem post-undo
+					 */
+					sipo->flag |= SIPO_TEMP_NEEDCHANSYNC;
 				}
 				else if (sl->spacetype == SPACE_BUTS) {
 					SpaceButs *sbuts = (SpaceButs *)sl;
@@ -5547,10 +5552,10 @@ void lib_link_screen_restore(Main *newmain, bScreen *curscreen, Scene *curscene)
 					SpaceAction *saction = (SpaceAction *)sl;
 					
 					saction->action = restore_pointer_by_name(newmain, (ID *)saction->action, 1);
-					saction->ads.source= restore_pointer_by_name(newmain, (ID *)saction->ads.source, 1);
+					saction->ads.source = restore_pointer_by_name(newmain, (ID *)saction->ads.source, 1);
 					
 					if (saction->ads.filter_grp)
-						saction->ads.filter_grp= restore_pointer_by_name(newmain, (ID *)saction->ads.filter_grp, 0);
+						saction->ads.filter_grp = restore_pointer_by_name(newmain, (ID *)saction->ads.filter_grp, 0);
 						
 					
 					/* force recalc of list of channels, potentially updating the active action 
diff --git a/source/blender/editors/space_graph/space_graph.c b/source/blender/editors/space_graph/space_graph.c
index 756e6997fc8..f4cb4ec3d05 100644
--- a/source/blender/editors/space_graph/space_graph.c
+++ b/source/blender/editors/space_graph/space_graph.c
@@ -189,6 +189,8 @@ static void graph_init(struct wmWindowManager *UNUSED(wm), ScrArea *sa)
 		sipo->ads->source = (ID *)(G.main->scene.first); // FIXME: this is a really nasty hack here for now...
 	}
 	
+	/* force immediate init of any invalid F-Curve colors */
+	sipo->flag |= SIPO_TEMP_NEEDCHANSYNC;
 	ED_area_tag_refresh(sa);
 }
 
@@ -477,7 +479,13 @@ static void graph_listener(ScrArea *sa, wmNotifier *wmn)
 			if (wmn->data == ND_SPACE_GRAPH)
 				ED_area_tag_redraw(sa);
 			break;
-		
+		case NC_WINDOW:
+			if (sipo->flag & SIPO_TEMP_NEEDCHANSYNC) {
+				/* force redraw/refresh after undo/redo - prevents "black curve" problem */
+				ED_area_tag_refresh(sa);
+			}
+			break;
+			
 			// XXX: restore the case below if not enough updates occur...
 			//default:
 			//	if (wmn->data==ND_KEYS)