--- /dev/null	2017-07-07 09:32:00.000000000 -0700
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.test/src/org/graalvm/compiler/core/test/GraalDebugHandlersFactoryTest.java	2017-07-07 09:32:00.000000000 -0700
@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 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.
+ */
+package org.graalvm.compiler.core.test;
+
+import java.io.File;
+import java.io.IOException;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Comparator;
+
+import org.graalvm.compiler.printer.GraalDebugHandlersFactory;
+import org.graalvm.compiler.test.AddExports;
+import org.junit.Test;
+
+@AddExports("jdk.internal.vm.compiler/org.graalvm.compiler.printer")
+public class GraalDebugHandlersFactoryTest extends GraalCompilerTest {
+
+    @Test
+    public void createUniqueTest() throws Exception {
+        Field maxFileNameLengthField = GraalDebugHandlersFactory.class.getDeclaredField("MAX_FILE_NAME_LENGTH");
+        maxFileNameLengthField.setAccessible(true);
+        int maxFileNameLength = maxFileNameLengthField.getInt(null);
+        Method createUniqueMethod = GraalDebugHandlersFactory.class.getDeclaredMethod("createUnique", Path.class, String.class, String.class, String.class, boolean.class);
+        createUniqueMethod.setAccessible(true);
+        Path tmpDir = Files.createTempDirectory(Paths.get("."), "createUniqueTest");
+        try {
+            for (boolean createDirectory : new boolean[]{true, false}) {
+                for (String ext : new String[]{"", ".bgv", ".graph-strings"}) {
+                    for (int i = 0; i < maxFileNameLength + 5; i++) {
+                        String id = new String(new char[i]).replace('\0', 'i');
+                        String label = "";
+                        createUniqueMethod.invoke(null, tmpDir, id, label, ext, createDirectory);
+
+                        id = "";
+                        label = new String(new char[i]).replace('\0', 'l');
+                        createUniqueMethod.invoke(null, tmpDir, id, label, ext, createDirectory);
+                    }
+                }
+            }
+        } finally {
+            deleteTree(tmpDir);
+        }
+    }
+
+    private static void deleteTree(Path root) throws IOException {
+        Files.walk(root).sorted(Comparator.reverseOrder()).map(Path::toFile).forEach(File::delete);
+    }
+}