--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/langtools/tools/javap/WhitespaceTest.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2014, 2016, 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 8033581 8033798 8033726
+ * @summary Check whitespace in generated output
+ * @modules jdk.jdeps/com.sun.tools.javap
+ */
+
+import java.io.*;
+import java.util.*;
+
+public class WhitespaceTest {
+    public static void main(String... args) throws Exception {
+        new WhitespaceTest().run();
+    }
+
+    void run() throws Exception {
+        test("-v", "java.lang.String");
+        test("-XDtab:1", "-v", "java.lang.String");
+
+        String testClasses = System.getProperty("test.classes");
+        for (int i = 10; i < 40; i++)
+            test("-XDtab:" + i, "-v", "-classpath", testClasses, "WhitespaceTest$HelloWorld");
+
+        if (errors > 0)
+            throw new Exception(errors + " errors found");
+    }
+
+    void test(String... args) throws Exception {
+        // need to avoid "//" appearing as a constant in the constant pool
+        String slash = "/";
+        String doubleSlash = slash + slash;
+        System.out.println("test: " + Arrays.asList(args));
+        String out = javap(args);
+        for (String line: out.split("[\r\n]+")) {
+            if (line.endsWith(" "))
+                error("line has trailing whitespace: " + line);
+            int comment = line.indexOf(doubleSlash);
+            if (comment > 0 && line.charAt(comment - 1) != ' ') {
+                // make allowance for URLs
+                if (!line.matches(".*\\bfile:/{3}.*"))
+                    error("no space before comment: " + line);
+            }
+            if (line.matches(" +}"))
+                error("bad indentation: " + line);
+        }
+    }
+
+    String javap(String... args) throws Exception {
+        StringWriter sw = new StringWriter();
+        PrintWriter out = new PrintWriter(sw);
+        int rc = com.sun.tools.javap.Main.run(args, out);
+        out.close();
+        System.out.println(sw.toString());
+        if (rc < 0)
+            throw new Exception("javap exited, rc=" + rc);
+        return sw.toString();
+    }
+
+    void error(String msg) {
+        System.out.println("Error: " + msg);
+        errors++;
+    }
+
+    int errors;
+
+    // small class to test repeatedly with different tab values
+    static class HelloWorld {
+        public static void main(String... args) {
+            System.out.println("Hello World!");
+        }
+    }
+}
+
+