diff --git a/hadoop-mapreduce-project/CHANGES.txt b/hadoop-mapreduce-project/CHANGES.txt
index e6477d83ca..0285fe80ef 100644
--- a/hadoop-mapreduce-project/CHANGES.txt
+++ b/hadoop-mapreduce-project/CHANGES.txt
@@ -261,6 +261,9 @@ Release 0.23.1 - Unreleased
     MAPREDUCE-3519. Fixed a deadlock in NodeManager LocalDirectories's handling
     service. (Ravi Gummadi via vinodkv)
 
+    MAPREDUCE-3527. Fix minor API incompatibilities between 1.0 and 0.23.
+    (tomwhite)
+
 Release 0.23.0 - 2011-11-01 
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/InvalidJobConfException.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/InvalidJobConfException.java
index 3f1a74e63c..ebd1e0f6b9 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/InvalidJobConfException.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/InvalidJobConfException.java
@@ -41,5 +41,13 @@ public InvalidJobConfException() {
   public InvalidJobConfException(String msg) {
     super(msg);
   }
+  
+  public InvalidJobConfException(String msg, Throwable t) {
+    super(msg, t);
+  }
+
+  public InvalidJobConfException(Throwable t) {
+    super(t);
+  }
 
 }
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/JobClient.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/JobClient.java
index 1b0b453ddd..cc586bf2f9 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/JobClient.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/JobClient.java
@@ -420,6 +420,16 @@ public boolean isRetired() throws IOException {
     boolean monitorAndPrintJob() throws IOException, InterruptedException {
       return job.monitorAndPrintJob();
     }
+    
+    @Override
+    public String getFailureInfo() throws IOException {
+      try {
+        return job.getStatus().getFailureInfo();
+      } catch (InterruptedException ie) {
+        throw new IOException(ie);
+      }
+    }
+
   }
 
   Cluster cluster;
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/RunningJob.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/RunningJob.java
index b3af4f6c98..53b7188e9b 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/RunningJob.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/RunningJob.java
@@ -223,4 +223,11 @@ public TaskCompletionEvent[] getTaskCompletionEvents(int startFrom)
    * @throws IOException
    */
   public boolean isRetired() throws IOException;
+  
+  /**
+   * Get failure info for the job.
+   * @return the failure info for the job.
+   * @throws IOException
+   */
+  public String getFailureInfo() throws IOException;
 }
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/lib/CombineFileInputFormat.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/lib/CombineFileInputFormat.java
index 96a30b010c..35dd3d7e5c 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/lib/CombineFileInputFormat.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapred/lib/CombineFileInputFormat.java
@@ -23,7 +23,10 @@
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.PathFilter;
+import org.apache.hadoop.mapred.FileInputFormat;
 import org.apache.hadoop.mapred.InputFormat;
 import org.apache.hadoop.mapred.InputSplit;
 import org.apache.hadoop.mapred.JobConf;
@@ -115,5 +118,18 @@ public org.apache.hadoop.mapreduce.RecordReader<K, V> createRecordReader(
       TaskAttemptContext context) throws IOException {
     return null;
   }
+  
+  /** List input directories.
+   * Subclasses may override to, e.g., select only files matching a regular
+   * expression. 
+   * 
+   * @param job the job to list input paths for
+   * @return array of FileStatus objects
+   * @throws IOException if zero items.
+   */
+  protected FileStatus[] listStatus(JobConf job) throws IOException {
+    List<FileStatus> result = super.listStatus(new Job(job));
+    return result.toArray(new FileStatus[result.size()]);
+  }
 
 }
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/TaskAttemptID.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/TaskAttemptID.java
index 16fd96210a..70fcf1024c 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/TaskAttemptID.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/TaskAttemptID.java
@@ -90,6 +90,12 @@ public JobID getJobID() {
   public TaskID getTaskID() {
     return taskId;
   }
+  
+  /**Returns whether this TaskID is a map ID */
+  @Deprecated
+  public boolean isMap() {
+    return taskId.isMap();
+  }
     
   /**Returns the TaskType of the TaskAttemptID */
   public TaskType getTaskType() {
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/TaskID.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/TaskID.java
index a09282f2bd..c98ec904fa 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/TaskID.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/TaskID.java
@@ -100,6 +100,12 @@ public TaskID() {
   public JobID getJobID() {
     return jobId;
   }
+  
+  /**Returns whether this TaskID is a map ID */
+  @Deprecated
+  public boolean isMap() {
+    return type == TaskType.MAP;
+  }
     
   /**
    * Get the type of the task
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/lib/input/KeyValueLineRecordReader.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/lib/input/KeyValueLineRecordReader.java
index d44bccd911..6d661211cf 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/lib/input/KeyValueLineRecordReader.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/lib/input/KeyValueLineRecordReader.java
@@ -50,6 +50,8 @@ public class KeyValueLineRecordReader extends RecordReader<Text, Text> {
   
   private Text value;
   
+  public Class getKeyClass() { return Text.class; }
+  
   public KeyValueLineRecordReader(Configuration conf)
     throws IOException {