Index: trunk/src/org/openstreetmap/josm/data/osm/search/SearchCompiler.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/osm/search/SearchCompiler.java	(revision 18290)
+++ trunk/src/org/openstreetmap/josm/data/osm/search/SearchCompiler.java	(revision 18291)
@@ -2129,5 +2129,5 @@
             if (!tokenizer.readIfEqual(Token.RIGHT_PARENT))
                 throw new SearchParseError(Token.RIGHT_PARENT, tokenizer.nextToken());
-            return expression;
+            return expression != null ? expression : Always.INSTANCE;
         } else if (tokenizer.readIfEqual(Token.NOT)) {
             return new Not(parseFactor(tr("Missing operator for NOT")));