Small usability tweaks in Compositor:

- After making a Group, internal socket values are now copied to the
  group node, so an execute will give identical results
- After ungrouping, the cyclic dependency tagging didn't work well in
  all cases, showing a red noodle line and giving composite errors.
  For time being solved by calling the NodeSort twice.
- Viewer nodes now get previews updated always (used to be only the active)
  Note: this is not for previews inside of groups!

source/blender/blenkernel/intern/node.c

@@ -511,6 +511,17 @@ bNode *nodeMakeGroupFromSelected(bNodeTree *ntree)
 		}
 	}
 	
+	/* initialize variables of unused input sockets */
+	for(node= ngroup->nodes.first; node; node= node->next) {
+		for(sock= node->inputs.first; sock; sock= sock->next) {
+			if(sock->intern==0) {
+				bNodeSocket *nsock= groupnode_find_tosock(gnode, sock->own_index);
+				if(nsock) {
+					QUATCOPY(nsock->ns.vec, sock->ns.vec);
+				}
+			}
+		}
+	}
 	return gnode;
 }
 
@@ -715,6 +726,10 @@ int nodeGroupUnGroup(bNodeTree *ntree, bNode *gnode)
 	
 	nodeFreeNode(ntree, gnode);
 	
+	/* solve order goes fine, but the level tags not... doing it twice works for now. solve this once */
+	ntreeSolveOrder(ntree);
+	ntreeSolveOrder(ntree);
+
 	return 1;
 }
 

source/blender/blenkernel/intern/node_composite.c

@@ -609,18 +609,9 @@ static void node_composit_exec_viewer(void *data, bNode *node, bNodeStack **in,
 		generate_preview(node, cbuf);
 		free_compbuf(cbuf);
 
-	}	/* lets make only previews when not done yet, so activating doesnt update */
-	else if(in[0]->data && node->preview && node->preview->rect==NULL) {
-		CompBuf *cbuf, *inbuf= in[0]->data;
-		
-		if(inbuf->type!=CB_RGBA) {
-			cbuf= alloc_compbuf(inbuf->x, inbuf->y, CB_RGBA, 1);
-			composit1_pixel_processor(node, cbuf, inbuf, in[0]->vec, do_copy_rgba, CB_RGBA);
-			generate_preview(node, cbuf);
-			free_compbuf(cbuf);
-		}
-		else
-			generate_preview(node, inbuf);
+	}
+	else if(in[0]->data) {
+		generate_preview(node, in[0]->data);
 	}
 }
 

source/blender/src/editnode.c

@@ -531,7 +531,6 @@ void node_ungroup(SpaceNode *snode)
 	else {
 		if(nodeGroupUnGroup(snode->edittree, gnode)) {
 			
-			ntreeSolveOrder(snode->edittree);
 			BIF_undo_push("Deselect all nodes");
 			allqueue(REDRAWNODE, 0);
 		}