src/share/classes/java/util/Collections.java

*** 1,7 ****
  /*
!  * Copyright (c) 1997, 2011, 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.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 1997, 2012, 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.  Oracle designates this
*** 1487,1496 ****
--- 1487,1498 ----
                  public V setValue(V value) {
                      throw new UnsupportedOperationException();
                  }
                  public int hashCode()    {return e.hashCode();}
                  public boolean equals(Object o) {
+                     if (this == o)
+                         return true;
                      if (!(o instanceof Map.Entry))
                          return false;
                      Map.Entry t = (Map.Entry)o;
                      return eq(e.getKey(),   t.getKey()) &&
                             eq(e.getValue(), t.getValue());
*** 1707,1716 ****
--- 1709,1720 ----
          SynchronizedSet(Set<E> s, Object mutex) {
              super(s, mutex);
          }
  
          public boolean equals(Object o) {
+             if (this == o)
+                 return true;
              synchronized (mutex) {return c.equals(o);}
          }
          public int hashCode() {
              synchronized (mutex) {return c.hashCode();}
          }
*** 1861,1870 ****
--- 1865,1876 ----
              super(list, mutex);
              this.list = list;
          }
  
          public boolean equals(Object o) {
+             if (this == o) 
+                 return true;
              synchronized (mutex) {return list.equals(o);}
          }
          public int hashCode() {
              synchronized (mutex) {return list.hashCode();}
          }
*** 2071,2080 ****
--- 2077,2088 ----
                  return values;
              }
          }
  
          public boolean equals(Object o) {
+             if (this == o)
+                 return true;
              synchronized (mutex) {return m.equals(o);}
          }
          public int hashCode() {
              synchronized (mutex) {return m.hashCode();}
          }