From d5d29b625fef0a6b6c69fca9c03330d85de585de Mon Sep 17 00:00:00 2001
From: Thomas Neidhart <tn@apache.org>
Date: Wed, 6 Mar 2013 21:57:53 +0000
Subject: [PATCH] [COLLECTIONS-445] Several workarounds for IBM JDKs flawed
 TreeMap.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/collections/trunk@1453585 13f79535-47bb-0310-9956-ffa450edef68
---
 .../commons/collections/bidimap/DualTreeBidiMap.java   |  6 +++++-
 .../commons/collections/map/AbstractMapTest.java       | 10 +++++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/main/java/org/apache/commons/collections/bidimap/DualTreeBidiMap.java b/src/main/java/org/apache/commons/collections/bidimap/DualTreeBidiMap.java
index bb31766c7..f9a934951 100644
--- a/src/main/java/org/apache/commons/collections/bidimap/DualTreeBidiMap.java
+++ b/src/main/java/org/apache/commons/collections/bidimap/DualTreeBidiMap.java
@@ -362,7 +362,11 @@ public class DualTreeBidiMap<K, V> extends AbstractDualBidiMap<K, V>
                 throw new IllegalArgumentException(
                         "Cannot use setValue() when the object being set is already in the map");
             }
-            return parent.put(last.getKey(), value);
+            final V oldValue = parent.put(last.getKey(), value);
+            // set also the value in the Map.Entry:
+            // due to a bug in IBM JDK where the Entry is not in sync with the underlying map
+            last.setValue(value);
+            return oldValue;
         }
 
         public void reset() {
diff --git a/src/test/java/org/apache/commons/collections/map/AbstractMapTest.java b/src/test/java/org/apache/commons/collections/map/AbstractMapTest.java
index aa48640ee..914f6c442 100644
--- a/src/test/java/org/apache/commons/collections/map/AbstractMapTest.java
+++ b/src/test/java/org/apache/commons/collections/map/AbstractMapTest.java
@@ -1921,7 +1921,8 @@ public abstract class AbstractMapTest<K, V> extends AbstractObjectTest {
      */
     private void views() {
         this.keySet = getMap().keySet();
-        this.values = getMap().values();
+        // see verifyValues: retrieve the values collection only when verifying them
+        // this.values = getMap().values();
         this.entrySet = getMap().entrySet();
     }
 
@@ -1999,6 +2000,13 @@ public abstract class AbstractMapTest<K, V> extends AbstractObjectTest {
 
     public void verifyValues() {
         final List<V> known = new ArrayList<V>(getConfirmed().values());
+        
+        // bug in IBM JDK: IBM J9 VM build 2.4, JRE 1.6.0 IBM J9 2.4 Linux x86-32 jvmxi3260sr12-20121024_126067
+        // a call to values() on an empty map retrieved via TreeMap#headMap or tailMap
+        // will render the values view unusable: resulting in NullPointExceptions or missing values
+        // it will also not recover, as the value view is cached internally
+        values = getMap().values();
+        
         final List<V> test = new ArrayList<V>(values);
 
         final int size = getConfirmed().size();