Index: trunk/test/unit/org/openstreetmap/josm/io/GeoJSONReaderTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/io/GeoJSONReaderTest.java	(revision 15864)
+++ trunk/test/unit/org/openstreetmap/josm/io/GeoJSONReaderTest.java	(revision 15865)
@@ -7,5 +7,7 @@
 import static org.junit.Assert.assertTrue;
 
+import java.io.ByteArrayInputStream;
 import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
@@ -133,4 +135,13 @@
     }
 
+    /**
+     * Test reading a JSON file which is not a proper GeoJSON (type missing).
+     * @throws IllegalDataException always
+     */
+    @Test(expected = IllegalDataException.class)
+    public void testReadGeoJsonWithoutType() throws IllegalDataException {
+        new GeoJSONReader().doParseDataSet(new ByteArrayInputStream("{}".getBytes(StandardCharsets.UTF_8)), null);
+    }
+
     private static boolean areEqualNodes(final OsmPrimitive p1, final OsmPrimitive p2) {
         return (p1 instanceof Node)