From 37b6aedcd013f7f01502e46f0528c9552dc52d96 Mon Sep 17 00:00:00 2001
From: Stephen Colebourne <scolebourne@apache.org>
Date: Sat, 7 May 2005 17:13:40 +0000
Subject: [PATCH] Fix so putAll works with an empty map bug 34686, reported by
 Marc Lottman

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/collections/trunk@169097 13f79535-47bb-0310-9956-ffa450edef68
---
 .../collections/map/TransformedMap.java       |  3 +++
 .../collections/map/AbstractTestMap.java      | 27 +++++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/java/org/apache/commons/collections/map/TransformedMap.java b/src/java/org/apache/commons/collections/map/TransformedMap.java
index 383673f07..36ef470f3 100644
--- a/src/java/org/apache/commons/collections/map/TransformedMap.java
+++ b/src/java/org/apache/commons/collections/map/TransformedMap.java
@@ -150,6 +150,9 @@ public class TransformedMap
      * @throws the transformed object
      */
     protected Map transformMap(Map map) {
+        if (map.isEmpty()) {
+            return map;
+        }
         Map result = new LinkedMap(map.size());
         for (Iterator it = map.entrySet().iterator(); it.hasNext(); ) {
             Map.Entry entry = (Map.Entry) it.next();
diff --git a/src/test/org/apache/commons/collections/map/AbstractTestMap.java b/src/test/org/apache/commons/collections/map/AbstractTestMap.java
index a854752b0..4bf996c33 100644
--- a/src/test/org/apache/commons/collections/map/AbstractTestMap.java
+++ b/src/test/org/apache/commons/collections/map/AbstractTestMap.java
@@ -907,23 +907,46 @@ public abstract class AbstractTestMap extends AbstractTestObject {
             return;
         }
 
+        // check putAll OK adding empty map to empty map
         resetEmpty();
+        assertEquals(0, map.size());
+        map.putAll(new HashMap());
+        assertEquals(0, map.size());
 
+        // check putAll OK adding empty map to non-empty map
+        resetFull();
+        int size = map.size();
+        map.putAll(new HashMap());
+        assertEquals(size, map.size());
+
+        // check putAll OK adding non-empty map to empty map
+        resetEmpty();
         Map m2 = makeFullMap();
-
         map.putAll(m2);
         confirmed.putAll(m2);
         verify();
 
+        // check putAll OK adding non-empty JDK map to empty map
         resetEmpty();
-
         m2 = makeConfirmedMap();
         Object[] keys = getSampleKeys();
         Object[] values = getSampleValues();
         for(int i = 0; i < keys.length; i++) {
             m2.put(keys[i], values[i]);
         }
+        map.putAll(m2);
+        confirmed.putAll(m2);
+        verify();
 
+        // check putAll OK adding non-empty JDK map to non-empty map
+        resetEmpty();
+        m2 = makeConfirmedMap();
+        map.put(keys[0], values[0]);
+        confirmed.put(keys[0], values[0]);
+        verify();
+        for(int i = 1; i < keys.length; i++) {
+            m2.put(keys[i], values[i]);
+        }
         map.putAll(m2);
         confirmed.putAll(m2);
         verify();