--- old/src/java.base/share/classes/java/util/Calendar.java	2018-09-05 11:46:53.291283398 -0700
+++ new/src/java.base/share/classes/java/util/Calendar.java	2018-09-05 11:46:52.927276011 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2018, 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
@@ -3326,7 +3326,9 @@
                 other.stamp[i] = stamp[i];
                 other.isSet[i] = isSet[i];
             }
-            other.zone = (TimeZone) zone.clone();
+            if (!sharedZone) {
+                other.zone = (TimeZone) zone.clone();
+            }
             return other;
         }
         catch (CloneNotSupportedException e) {