--- /dev/null	2016-05-17 12:01:17.473251102 +0900
+++ new/test/java/util/Calendar/Bug6234795.java	2016-05-23 13:58:11.503994121 +0900
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2005, 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 6234795
+ * @summary Rolling of HOUR or HOUR_OF_SET must set the other hour field.
+ */
+
+import java.util.GregorianCalendar;
+import static java.util.Calendar.AM;
+import static java.util.Calendar.AM_PM;
+import static java.util.Calendar.HOUR;
+import static java.util.Calendar.HOUR_OF_DAY;
+import static java.util.Calendar.SEPTEMBER;
+import java.util.Locale;
+import java.util.TimeZone;
+
+public class Bug6234795 {
+    public static void main(String[] args) {
+        testRoll(HOUR);
+        testRoll(HOUR_OF_DAY);
+    }
+
+    static void testRoll(int field) {
+        GregorianCalendar cal = new GregorianCalendar(TimeZone.getTimeZone("GMT"), Locale.US);
+        cal.clear();
+        cal.set(2005, SEPTEMBER, 12);
+
+        int otherField = (field == HOUR) ? HOUR_OF_DAY : HOUR;
+        int unit = (field == HOUR) ? 12 : 24;
+        int h;
+        for (h = 0; h <= 72; h++) {
+            int hour = cal.get(otherField);
+            int expected = h % 12;
+            if (hour != expected) {
+                throw new RuntimeException((field == HOUR ? "HOUR" : "HOUR_OF_DAY")
+                                           + "+: h=" + h + ", got " + hour
+                                           + ", expected " + expected);
+            }
+            if (field == HOUR_OF_DAY) {
+                int ampm = cal.get(AM_PM);
+                expected = (h % unit) / 12;
+                if (ampm != expected) {
+                    throw new RuntimeException((field == HOUR ? "HOUR" : "HOUR_OF_DAY")
+                                               + "+: h=" + h + ", got "
+                                               + toString(ampm)
+                                               + ", expected " + toString(expected));
+                }
+            }
+            cal.roll(field, +1);
+        }
+        for (; h >= 0; h--) {
+            int hour = cal.get(otherField);
+            int expected = h % 12;
+            if (hour != expected) {
+                throw new RuntimeException((field == HOUR ? "HOUR" : "HOUR_OF_DAY")
+                                           + "-: h=" + h + ", got " + hour
+                                           + ", expected " + expected);
+            }
+            if (field == HOUR_OF_DAY) {
+                int ampm = cal.get(AM_PM);
+                expected = (h % unit) / 12;
+                if (ampm != expected) {
+                    throw new RuntimeException((field == HOUR ? "HOUR" : "HOUR_OF_DAY")
+                                               + "-: h=" + h + ", got " + toString(ampm)
+                                               + ", expected " + toString(expected));
+                }
+            }
+            cal.roll(field, -1);
+        }
+    }
+
+    static String toString(int ampm) {
+        return ampm == AM ? "AM" : "PM";
+    }
+}