Fix HADOOP-69. NPE when getting hints for a non-existant file chunk. Contributed by Bryan Pendelton.

git-svn-id: https://svn.apache.org/repos/asf/lucene/hadoop/trunk@395665 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -69,6 +69,9 @@ Trunk (unreleased)
     use.  Now a global RPC connection pool is used again, as
     originally intended.  (cutting)
 
+20. Fix HADOOP-69.  Don't throw a NullPointerException when getting
+    hints for non-existing file split.  (Bryan Pendelton via cutting)
+
 
 Release 0.1.1 - 2006-04-08
 

src/java/org/apache/hadoop/dfs/FSNamesystem.java

@@ -617,9 +617,11 @@ class FSNamesystem implements FSConstants {
             for (int i = startBlock; i <= endBlock; i++) {
                 TreeSet containingNodes = (TreeSet) blocksMap.get(blocks[i]);
                 Vector v = new Vector();
-                for (Iterator it = containingNodes.iterator(); it.hasNext(); ) {
+                if (containingNodes != null) {
+                  for (Iterator it =containingNodes.iterator(); it.hasNext();) {
                     DatanodeInfo cur = (DatanodeInfo) it.next();
                     v.add(cur.getHost());
+                  }
                 }
                 hosts[i-startBlock] = (UTF8[]) v.toArray(new UTF8[v.size()]);
             }