--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/javax/imageio/PNGSuffixes.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 4394924
+ * @summary Checks for spurious leading "." in PNG file suffixes
+ * @modules java.desktop/com.sun.imageio.plugins.png
+ */
+
+import com.sun.imageio.plugins.png.PNGImageWriterSpi;
+
+public class PNGSuffixes {
+
+    public static void main(String[] args) {
+        String[] suffixes = new PNGImageWriterSpi().getFileSuffixes();
+        for (int i = 0; i < suffixes.length; i++) {
+            if (suffixes[i].startsWith(".")) {
+                throw new RuntimeException("Found a \".\" in a suffix!");
+            }
+        }
+    }
+}