Index: trunk/src/org/openstreetmap/josm/gui/mappaint/styleelement/placement/PositionForAreaStrategy.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/mappaint/styleelement/placement/PositionForAreaStrategy.java	(revision 11753)
+++ trunk/src/org/openstreetmap/josm/gui/mappaint/styleelement/placement/PositionForAreaStrategy.java	(revision 11754)
@@ -39,9 +39,10 @@
      * @param isDoubleTranslationBug <code>true</code> to fix a glyph placement bug.
      *
-     * @return The glyph vectors. Or <code>null</code> if the text could not be transformed.
+     * @return The glyph vectors.
+     * @throws UnsupportedOperationException if {@link #supportsGlyphVector()} returns false
      */
     default List<GlyphVector> generateGlyphVectors(
             MapViewPath path, Rectangle2D nb, List<GlyphVector> gvs, boolean isDoubleTranslationBug) {
-        return null;
+        throw new UnsupportedOperationException("Single glyph transofrmation is not supported by this implementation");
     }