diff --git a/CHANGES.txt b/CHANGES.txt
index 40d6345e19..a3421b4f3f 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -68,6 +68,9 @@ Trunk (unreleased changes)
     HADOOP-5698. Change org.apache.hadoop.examples.MultiFileWordCount to 
     use new mapreduce api. (Amareshwari Sriramadasu via sharad)
 
+    HADOOP-5913. Provide ability to an administrator to stop and start
+    job queues. (Rahul Kumar Singh and Hemanth Yamijala via yhemanth)
+
   NEW FEATURES
 
     HADOOP-4268. Change fsck to use ClientProtocol methods so that the
@@ -149,6 +152,9 @@ Trunk (unreleased changes)
     HADOOP-5170. Allows jobs to set max maps/reduces per-node and per-cluster.
     (Matei Zaharia via ddas)
 
+    HADOOP-5897. Add name-node metrics to capture java heap usage.
+    (Suresh Srinivas via shv)
+
   IMPROVEMENTS
 
     HADOOP-4565. Added CombineFileInputFormat to use data locality information
@@ -444,6 +450,12 @@ Trunk (unreleased changes)
     HADOOP-5938. Change org.apache.hadoop.mapred.jobcontrol to use new
     api. (Amareshwari Sriramadasu via sharad)
 
+    HADOOP-2141. Improves the speculative execution heuristic. The heuristic
+    is currently based on the progress-rates of tasks and the expected time
+    to complete. Also, statistics about trackers are collected, and speculative
+    tasks are not given to the ones deduced to be slow. 
+    (Andy Konwinski and ddas)
+
   OPTIMIZATIONS
 
     HADOOP-5595. NameNode does not need to run a replicator to choose a
@@ -820,6 +832,9 @@ Trunk (unreleased changes)
     LD_LIBRARY_PATH and other environment variables.
     (Sreekanth Ramakrishnan via yhemanth)
 
+    HADOOP-4041. IsolationRunner does not work as documented.
+    (Philip Zeyliger via tomwhite)
+
 Release 0.20.1 - Unreleased
 
   INCOMPATIBLE CHANGES
@@ -948,6 +963,9 @@ Release 0.20.1 - Unreleased
     (usually HDFS) is started at nearly the same time as the JobTracker. 
     (Amar Kamat via ddas)
 
+    HADOOP-5920. Fixes a testcase failure for TestJobHistory. 
+    (Amar Kamat via ddas)
+
 Release 0.20.0 - 2009-04-15
 
   INCOMPATIBLE CHANGES
@@ -2982,6 +3000,10 @@ Release 0.18.4 - Unreleased
 
     HADOOP-5644. Namenode is stuck in safe mode. (suresh Srinivas via hairong)
 
+    HADOOP-6017. Lease Manager in NameNode does not handle certain characters
+    in filenames. This results in fatal errors in Secondary NameNode and while
+    restrating NameNode. (Tsz Wo (Nicholas), SZE via rangadi)
+
 Release 0.18.3 - 2009-01-27
 
   IMPROVEMENTS
diff --git a/src/java/org/apache/hadoop/fs/LocalDirAllocator.java b/src/java/org/apache/hadoop/fs/LocalDirAllocator.java
index 5d04d280da..1aa4663b15 100644
--- a/src/java/org/apache/hadoop/fs/LocalDirAllocator.java
+++ b/src/java/org/apache/hadoop/fs/LocalDirAllocator.java
@@ -33,7 +33,7 @@
  * files. The way it works is that it is kept track what disk was last
  * allocated for a file write. For the current request, the next disk from
  * the set of disks would be allocated if the free space on the disk is 
- * sufficient enough to accomodate the file that is being considered for
+ * sufficient enough to accommodate the file that is being considered for
  * creation. If the space requirements cannot be met, the next disk in order
  * would be tried and so on till a disk is found with sufficient capacity.
  * Once a disk with sufficient space is identified, a check is done to make
@@ -69,6 +69,9 @@ public class LocalDirAllocator {
                  new TreeMap<String, AllocatorPerContext>();
   private String contextCfgItemName;
 
+  /** Used when size of file to be allocated is unknown. */
+  public static final int SIZE_UNKNOWN = -1;
+
   /**Create an allocator object
    * @param contextCfgItemName
    */
@@ -105,10 +108,11 @@ private AllocatorPerContext obtainContext(String contextCfgItemName) {
    */
   public Path getLocalPathForWrite(String pathStr, 
       Configuration conf) throws IOException {
-    return getLocalPathForWrite(pathStr, -1, conf);
+    return getLocalPathForWrite(pathStr, SIZE_UNKNOWN, conf);
   }
   
-  /** Get a path from the local FS. Pass size as -1 if not known apriori. We
+  /** Get a path from the local FS. Pass size as 
+   *  SIZE_UNKNOWN if not known apriori. We
    *  round-robin over the set of disks (via the configured dirs) and return
    *  the first complete path which has enough space 
    *  @param pathStr the requested path (this will be created on the first 
@@ -274,7 +278,7 @@ int getCurrentDirectoryIndex() {
      */
     public synchronized Path getLocalPathForWrite(String path, 
         Configuration conf) throws IOException {
-      return getLocalPathForWrite(path, -1, conf);
+      return getLocalPathForWrite(path, SIZE_UNKNOWN, conf);
     }
 
     /** Get a path from the local FS. If size is known, we go
@@ -296,7 +300,7 @@ public synchronized Path getLocalPathForWrite(String pathStr, long size,
       }
       Path returnPath = null;
       
-      if(size == -1) {  //do roulette selection: pick dir with probability 
+      if(size == SIZE_UNKNOWN) {  //do roulette selection: pick dir with probability 
                     //proportional to available size
         long[] availableOnDisk = new long[dirDF.length];
         long totalAvailable = 0;
@@ -344,7 +348,8 @@ public synchronized Path getLocalPathForWrite(String pathStr, long size,
           "directory for " + pathStr);
     }
 
-    /** Creates a file on the local FS. Pass size as -1 if not known apriori. We
+    /** Creates a file on the local FS. Pass size as 
+     * {@link LocalDirAllocator.SIZE_UNKNOWN} if not known apriori. We
      *  round-robin over the set of disks (via the configured dirs) and return
      *  a file on the first path which has enough space. The file is guaranteed
      *  to go away when the JVM exits.
diff --git a/src/java/org/apache/hadoop/util/StringUtils.java b/src/java/org/apache/hadoop/util/StringUtils.java
index c327400546..2c1a5fe37b 100644
--- a/src/java/org/apache/hadoop/util/StringUtils.java
+++ b/src/java/org/apache/hadoop/util/StringUtils.java
@@ -677,4 +677,24 @@ public static String byteDesc(long len) {
   public static synchronized String limitDecimalTo2(double d) {
     return decimalFormat.format(d);
   }
+  
+  /**
+   * Concatenates strings, using a separator.
+   *
+   * @param separator Separator to join with.
+   * @param strings Strings to join.
+   */
+  public static String join(CharSequence separator, Iterable<String> strings) {
+    StringBuffer sb = new StringBuffer();
+    boolean first = true;
+    for (String s : strings) {
+      if (first) {
+        first = false;
+      } else {
+        sb.append(separator);
+      }
+      sb.append(s);
+    }
+    return sb.toString();
+  }
 }
diff --git a/src/test/core/org/apache/hadoop/util/TestStringUtils.java b/src/test/core/org/apache/hadoop/util/TestStringUtils.java
index e68609ae2f..7aa6a7a333 100644
--- a/src/test/core/org/apache/hadoop/util/TestStringUtils.java
+++ b/src/test/core/org/apache/hadoop/util/TestStringUtils.java
@@ -18,6 +18,9 @@
 
 package org.apache.hadoop.util;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import junit.framework.TestCase;
 
 public class TestStringUtils extends TestCase {
@@ -118,4 +121,15 @@ public void testTraditionalBinaryPrefix() throws Exception {
     assertEquals(-1259520L, StringUtils.TraditionalBinaryPrefix.string2long("-1230k"));
     assertEquals(956703965184L, StringUtils.TraditionalBinaryPrefix.string2long("891g"));
   }
+
+  public void testJoin() {
+    List<String> s = new ArrayList<String>();
+    s.add("a");
+    s.add("b");
+    s.add("c");
+    assertEquals("", StringUtils.join(":", s.subList(0, 0)));
+    assertEquals("a", StringUtils.join(":", s.subList(0, 1)));
+    assertEquals("a:b", StringUtils.join(":", s.subList(0, 2)));
+    assertEquals("a:b:c", StringUtils.join(":", s.subList(0, 3)));
+  }
 }