Index: src/main/java/org/apache/naming/resources/FileDirContext.java
===================================================================
--- src/main/java/org/apache/naming/resources/FileDirContext.java	(revision 26198)
+++ src/main/java/org/apache/naming/resources/FileDirContext.java	(working copy)
@@ -64,6 +64,7 @@
 import java.util.Date;
 import java.util.Map;
 import java.util.WeakHashMap;
+import java.util.logging.Logger;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.InputStream;
@@ -91,6 +92,8 @@
 import org.apache.naming.NamingContextBindingsEnumeration;
 import org.apache.naming.NamingContextEnumeration;
 
+import com.sun.logging.LogDomains;
+
 /**
  * Filesystem Directory Context implementation helper class.
  *
@@ -100,6 +103,8 @@
 
 public class FileDirContext extends BaseDirContext {
 
+    private static final Logger logger = LogDomains.getLogger(
+            FileDirContext.class, LogDomains.WEB_LOGGER);
 
     // -------------------------------------------------------------- Constants
 
@@ -1004,6 +1009,15 @@
         if (!file.isDirectory())
             return entries;
         String[] names = file.list();
+        if (names==null) {
+            /* Some IO error occurred such as bad file permissions,
+             * lack of file descriptors.
+             * Prevent a NPE with Arrays.sort(names) */
+            logger.warning(sm.getString("fileResources.listingNull",
+                                  file.getAbsolutePath()));
+            return entries;
+        }
+
         Arrays.sort(names);             // Sort alphabetically
         if (names == null)
             return entries;
Index: src/main/resources/org/apache/naming/resources/LocalStrings.properties
===================================================================
--- src/main/resources/org/apache/naming/resources/LocalStrings.properties	(revision 26198)
+++ src/main/resources/org/apache/naming/resources/LocalStrings.properties	(working copy)
@@ -75,3 +75,4 @@
 standardResources.notStarted=PWC4447: Resources has not yet been started
 standardResources.null=PWC4448: Document base cannot be null
 standardResources.slash=PWC4449: Document base {0} must not end with a slash
+fileResources.listingNull=PWC4450: Could not get dir listing for {0}