Index: trunk/test/unit/org/openstreetmap/josm/gui/mappaint/mapcss/MapCSSParserTest.groovy
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/mappaint/mapcss/MapCSSParserTest.groovy	(revision 7123)
+++ trunk/test/unit/org/openstreetmap/josm/gui/mappaint/mapcss/MapCSSParserTest.groovy	(revision 7124)
@@ -310,3 +310,11 @@
         assert !s1.matches(new Environment().withPrimitive(w))
     }
+
+    @Test
+    public void testInvalidBaseSelector() throws Exception {
+        def css = new MapCSSStyleSource("invalid_base[key=value] {}")
+        css.loadStyleSource()
+        assert !css.getErrors().isEmpty()
+        assert css.getErrors().iterator().next().toString().contains("Unknown MapCSS base selector invalid_base")
+    }
 }