Index: src/layer_grp.c
===================================================================
--- src/layer_grp.c	(revision 10447)
+++ src/layer_grp.c	(revision 10448)
@@ -692,7 +692,7 @@
 	d = (gid1 < gid2) ? +1 : -1;
 	cnt = 0;
 	for(gid = gid1; gid != gid2; gid += d) {
-		if (pcb->LayerGroups.grp[gid].type & mask)
+		if ((pcb->LayerGroups.grp[gid].type & mask) == mask)
 			cnt++;
 	}
 	*diff = cnt;