group refcount checking was inconsistent.

- if a group has one or more objects in it, it gets a refcount of 1 on load (unchanged from before)
- dupli-groups, and materials no longer add/remove a reference.
- now groups are only freed when they contain no objects or when manually unlinked.	

4 files changed, 4 insertions, 7 deletions

diff --git a/source/blender/editors/object/object_add.c b/source/blender/editors/object/object_add.c
index 757c167c496..2299207eaa9 100644
--- a/source/blender/editors/object/object_add.c
+++ b/source/blender/editors/object/object_add.c
@@ -754,8 +754,7 @@ static int group_instance_add_exec(bContext *C, wmOperator *op)
 		rename_id(&ob->id, group->id.name+2);
 		ob->dup_group= group;
 		ob->transflag |= OB_DUPLIGROUP;
-		id_us_plus(&group->id);
-
+		id_lib_extern(&group->id);
 
 		WM_event_add_notifier(C, NC_OBJECT|ND_DRAW, ob);
 
diff --git a/source/blender/editors/object/object_edit.c b/source/blender/editors/object/object_edit.c
index d3226b1adf4..5fe09f0083e 100644
--- a/source/blender/editors/object/object_edit.c
+++ b/source/blender/editors/object/object_edit.c
@@ -1408,7 +1408,7 @@ void copy_attr(Scene *scene, View3D *v3d, short event)
 
 					base->object->dup_group= ob->dup_group;
 					if(ob->dup_group)
-						id_us_plus((ID *)ob->dup_group);
+						id_lib_extern(&ob->dup_group->id);
 				}
 				else if(event==7) {	/* mass */
 					base->object->mass= ob->mass;
diff --git a/source/blender/editors/object/object_relations.c b/source/blender/editors/object/object_relations.c
index fbc6075796c..8d488eeabac 100644
--- a/source/blender/editors/object/object_relations.c
+++ b/source/blender/editors/object/object_relations.c
@@ -1250,10 +1250,9 @@ static int make_links_data_exec(bContext *C, wmOperator *op)
 					BKE_copy_animdata_id((ID *)obt->data, (ID *)ob->data);
 					break;
 				case MAKE_LINKS_DUPLIGROUP:
-					if(ob->dup_group) ob->dup_group->id.us--;
 					obt->dup_group= ob->dup_group;
 					if(obt->dup_group) {
-						id_us_plus((ID *)obt->dup_group);
+						id_lib_extern(&obt->dup_group->id);
 						obt->transflag |= OB_DUPLIGROUP;
 					}
 					break;
diff --git a/source/blender/editors/space_outliner/outliner.c b/source/blender/editors/space_outliner/outliner.c
index 794c700f8ce..95e2cb920fc 100644
--- a/source/blender/editors/space_outliner/outliner.c
+++ b/source/blender/editors/space_outliner/outliner.c
@@ -1411,7 +1411,7 @@ static void outliner_build_tree(Main *mainvar, Scene *scene, SpaceOops *soops)
 		GroupObject *go;
 		
 		for(group= mainvar->group.first; group; group= group->id.next) {
-			if(group->id.us) {
+			if(group->gobject.first) {
 				te= outliner_add_element(soops, &soops->tree, group, NULL, 0, 0);
 				tselem= TREESTORE(te);
 				
@@ -3124,7 +3124,6 @@ static void unlink_group_cb(bContext *C, Scene *scene, TreeElement *te, TreeStor
 		if( GS(tsep->id->name)==ID_OB) {
 			Object *ob= (Object *)tsep->id;
 			ob->dup_group= NULL;
-			group->id.us--;
 		}
 	}
 	else {