Index: trunk/src/org/openstreetmap/josm/actions/AlignInLineAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/AlignInLineAction.java	(revision 16135)
+++ trunk/src/org/openstreetmap/josm/actions/AlignInLineAction.java	(revision 16136)
@@ -195,5 +195,5 @@
         List<Node> selectedNodes = new ArrayList<>(ds.getSelectedNodes());
         List<Way> selectedWays = new ArrayList<>(ds.getSelectedWays());
-        selectedWays.removeIf(OsmPrimitive::isIncomplete);
+        selectedWays.removeIf(w -> w.isIncomplete() || w.isEmpty());
 
         // Decide what to align based on selection: