8160518: Semicolon is not recognized as comment starting character (Kerberos)

Reviewed-by: weijun, coffeys

src/share/classes/sun/security/krb5/Config.java

@@ -525,9 +525,9 @@ public class Config {
                 String previous = null;
                 while ((line = br.readLine()) != null) {
                     line = line.trim();
-                    if (line.startsWith("#") || line.isEmpty()) {
+                    if (line.isEmpty() || line.startsWith("#") || line.startsWith(";")) {
                         // ignore comments and blank line
-                        // Comments start with #.
+                        // Comments start with '#' or ';'
                         continue;
                     }
                     // In practice, a subsection might look like:

test/sun/security/krb5/config/Semicolon.java

+/*
+ * Copyright (c) 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 8160518
+ * @summary Semicolon is not recognized as comment starting character
+ * @run main/othervm Semicolon
+ */
+
+import sun.security.krb5.Config;
+
+public class Semicolon {
+    public static void main(String[] args) throws Throwable {
+        System.setProperty("java.security.krb5.conf",
+                System.getProperty("test.src", ".") + "/comments.conf");
+        Config config = Config.getInstance();
+        config.get("section", "value");
+    }
+}

test/sun/security/krb5/config/comments.conf

+[section]
+
+#           comment
+ #          comment
+	 #  comment
+ 	#   comment
+;           comment
+ ;          comment
+	 ;  comment
+ 	;   comment
+
+value = true