8175000: jexec fails to execute simple helloworld.jar

Reviewed-by: ksrini, henryjen, stuefe

jdk/src/java.base/unix/native/launcher/jexec.c

 /*
- * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 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
@@ -332,7 +332,7 @@ const char * isJar(const char * path) {
 
                 if (end <= count) {
                     end -= 4; // make sure there are 4 bytes to read at start
-                    while (start < end) {
+                    while (start <= end) {
                         off_t xhid  = SH(buf, start);
                         off_t xdlen = SH(buf, start + 2);
 

jdk/test/tools/launcher/Jexec.java

+/*
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 8175000
+ * @summary test jexec
+ * @build TestHelper
+ * @run main Jexec
+ */
+
+import java.io.File;
+import java.io.IOException;
+
+public class Jexec extends TestHelper {
+    private final File testJar;
+    private final File jexecCmd;
+    private final String message = "Hello, do you read me ?";
+
+    Jexec() throws IOException {
+        jexecCmd = new File(JAVA_LIB, "jexec");
+        if (!jexecCmd.exists() || !jexecCmd.canExecute()) {
+            throw new Error("jexec: does not exist or not executable");
+        }
+
+        testJar = new File("test.jar");
+        StringBuilder tsrc = new StringBuilder();
+        tsrc.append("public static void main(String... args) {\n");
+        tsrc.append("   for (String x : args) {\n");
+        tsrc.append("        System.out.println(x);\n");
+        tsrc.append("   }\n");
+        tsrc.append("}\n");
+        createJar(testJar, tsrc.toString());
+    }
+
+    public static void main(String... args) throws Exception {
+        // linux is the only supported platform, give the others a pass
+        if (!isLinux) {
+            System.err.println("Warning: unsupported platform test passes vacuously");
+            return;
+        }
+        // ok to run the test now
+        Jexec t = new Jexec();
+        t.run(null);
+    }
+
+    @Test
+    void jexec() throws Exception {
+        TestResult tr = doExec(jexecCmd.getAbsolutePath(),
+                testJar.getAbsolutePath(), message);
+        if (!tr.isOK()) {
+            System.err.println(tr);
+            throw new Exception("incorrect exit value");
+        }
+        if (!tr.contains(message)) {
+            System.err.println(tr);
+            throw new Exception("expected message \'" + message + "\' not found");
+        }
+    }
+}