diff --git a/docs/manual/CoreTasks/pack.html b/docs/manual/CoreTasks/pack.html
index 3bf280694..b1243e9e5 100644
--- a/docs/manual/CoreTasks/pack.html
+++ b/docs/manual/CoreTasks/pack.html
@@ -10,8 +10,8 @@
 <h2><a name="pack">GZip/BZip2</a></h2>
 <h3>Description</h3>
 <p>Packs a file using the GZip or BZip2 algorithm.
-These tasks do not do any dependency checking; the output file is 
-always generated</p>
+The output file is only generated if it doesn't exist or the source
+file is newer.</p>
 <h3>Parameters</h3>
 <table border="1" cellpadding="2" cellspacing="0">
   <tr>
@@ -40,7 +40,7 @@ always generated</p>
   /&gt;</code></p>
 </blockquote>
 <hr>
-<p align="center">Copyright &copy; 2001 Apache Software Foundation. All rights
+<p align="center">Copyright &copy; 2001-2002 Apache Software Foundation. All rights
 Reserved.</p>
 
 </body>
diff --git a/src/main/org/apache/tools/ant/taskdefs/BUnzip2.java b/src/main/org/apache/tools/ant/taskdefs/BUnzip2.java
index 5df0c0918..2eaa47dfb 100644
--- a/src/main/org/apache/tools/ant/taskdefs/BUnzip2.java
+++ b/src/main/org/apache/tools/ant/taskdefs/BUnzip2.java
@@ -69,6 +69,8 @@ import org.apache.tools.bzip2.CBZip2InputStream;
  *
  * @author <a href="mailto:umagesh@rediffmail.com">Magesh Umasankar</a>
  *
+ * @since Ant 1.5
+ *
  * @ant.task category="packaging"
  */
 
diff --git a/src/main/org/apache/tools/ant/taskdefs/BZip2.java b/src/main/org/apache/tools/ant/taskdefs/BZip2.java
index de1e26776..ecb75b36f 100644
--- a/src/main/org/apache/tools/ant/taskdefs/BZip2.java
+++ b/src/main/org/apache/tools/ant/taskdefs/BZip2.java
@@ -67,6 +67,8 @@ import org.apache.tools.bzip2.CBZip2OutputStream;
  *
  * @author <a href="mailto:umagesh@rediffmail.com">Magesh Umasankar</a>
  *
+ * @since Ant 1.5
+ *
  * @ant.task category="packaging"
  */
 
diff --git a/src/main/org/apache/tools/ant/taskdefs/Pack.java b/src/main/org/apache/tools/ant/taskdefs/Pack.java
index 9e3dbc215..9822657ea 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Pack.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Pack.java
@@ -67,6 +67,8 @@ import org.apache.tools.ant.Task;
  * Abstract Base class for pack tasks.
  *
  * @author <a href="mailto:umagesh@rediffmail.com">Magesh Umasankar</a>
+ *
+ * @since Ant 1.5
  */
 
 public abstract class Pack extends Task {
diff --git a/src/main/org/apache/tools/ant/taskdefs/Unpack.java b/src/main/org/apache/tools/ant/taskdefs/Unpack.java
index b0f922557..567a46264 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Unpack.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Unpack.java
@@ -1,7 +1,7 @@
 /*
  * The Apache Software License, Version 1.1
  *
- * Copyright (c) 2001 The Apache Software Foundation.  All rights
+ * Copyright (c) 2001-2002 The Apache Software Foundation.  All rights
  * reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -63,6 +63,8 @@ import org.apache.tools.ant.Task;
  * Abstract Base class for unpack tasks.
  *
  * @author <a href="mailto:umagesh@apache.org">Magesh Umasankar</a>
+ *
+ * @since 1.5
  */
 
 public abstract class Unpack extends Task {
@@ -139,8 +141,13 @@ public abstract class Unpack extends Task {
     }
 
     public void execute() throws BuildException {
-        validate();
-        extract();
+        File savedDest = dest; // may be altered in validate
+        try {
+            validate();
+            extract();
+        } finally {
+            dest = savedDest;
+        }
     }
 
     protected abstract String getDefaultExtension();