Index: src/test/org/apache/lucene/store/TestLockFactory.java
===================================================================
--- src/test/org/apache/lucene/store/TestLockFactory.java	(revision 718246)
+++ src/test/org/apache/lucene/store/TestLockFactory.java	(working copy)
@@ -566,10 +566,12 @@
     private void rmDir(String dirName) {
         File dir = new java.io.File(dirName);
         String[] files = dir.list();            // clear old files
-        for (int i = 0; i < files.length; i++) {
+        if (files != null) {
+          for (int i = 0; i < files.length; i++) {
             File file = new File(dir, files[i]);
             file.delete();
+          }
+          dir.delete();
         }
-        dir.delete();
     }
 }
Index: src/test/org/apache/lucene/store/TestDirectory.java
===================================================================
--- src/test/org/apache/lucene/store/TestDirectory.java	(revision 718246)
+++ src/test/org/apache/lucene/store/TestDirectory.java	(working copy)
@@ -18,6 +18,7 @@
  */
 
 import org.apache.lucene.util.LuceneTestCase;
+import org.apache.lucene.util._TestUtil;
 
 import java.io.File;
 
@@ -115,5 +116,17 @@
     }
   }
 
+  // LUCENE-1464
+  public void testDontCreate() throws Throwable {
+    File path = new File(System.getProperty("tempDir"), "doesnotexist");
+    try {
+      assertTrue(!path.exists());
+      Directory dir = new FSDirectory(path, null);
+      assertTrue(!path.exists());
+      dir.close();
+    } finally {
+      _TestUtil.rmDir(path);
+    }
+  }
 }
 
Index: src/java/org/apache/lucene/index/SegmentInfos.java
===================================================================
--- src/java/org/apache/lucene/index/SegmentInfos.java	(revision 718246)
+++ src/java/org/apache/lucene/index/SegmentInfos.java	(working copy)
@@ -130,8 +130,6 @@
    */
   public static long getCurrentSegmentGeneration(Directory directory) throws IOException {
     String[] files = directory.list();
-    if (files == null)
-      throw new IOException("cannot read directory " + directory + ": list() returned null");
     return getCurrentSegmentGeneration(files);
   }
 
Index: src/java/org/apache/lucene/store/FSDirectory.java
===================================================================
--- src/java/org/apache/lucene/store/FSDirectory.java	(revision 719831)
+++ src/java/org/apache/lucene/store/FSDirectory.java	(working copy)
@@ -178,7 +178,7 @@
   public static FSDirectory getDirectory(File file, LockFactory lockFactory)
     throws IOException
   {
-    file = createCanonicalDir(file);
+    file = getCanonicalPath(file);
 
     FSDirectory dir;
     synchronized (DIRECTORIES) {
@@ -197,6 +197,7 @@
         if (lockFactory != null && lockFactory != dir.getLockFactory()) {
           throw new IOException("Directory was previously created with a different LockFactory instance; please pass null as the lockFactory instance and use setLockFactory to change it");
         }
+        dir.checked = false;
       }
     }
     synchronized (dir) {
@@ -256,17 +257,23 @@
   }
 
   // returns the canonical version of the directory, creating it if it doesn't exist.
-  private static File createCanonicalDir(File file) throws IOException {
-    file = new File(file.getCanonicalPath());
+  private static File getCanonicalPath(File file) throws IOException {
+    return new File(file.getCanonicalPath());
+  }
 
-    if (file.exists() && !file.isDirectory())
-      throw new IOException(file + " not a directory");
+  private boolean checked;
 
-    if (!file.exists())
-      if (!file.mkdirs())
-        throw new IOException("Cannot create directory: " + file);
+  final void createDir() throws IOException {
+    if (!checked) {
+      if (directory.exists() && !directory.isDirectory())
+        throw new IOException(directory + " not a directory");
 
-    return file;
+      if (!directory.exists())
+        if (!directory.mkdirs())
+          throw new IOException("Cannot create directory: " + directory);
+
+      checked = true;
+    }
   }
 
   private File directory = null;
@@ -283,7 +290,7 @@
    * Use {@link #getDirectory(String)} if singletons per path are needed.
    */
   public FSDirectory(File path, LockFactory lockFactory) throws IOException {
-    path = createCanonicalDir(path);
+    path = getCanonicalPath(path);
     init(path, lockFactory);
     refCount = 1;
   }
@@ -469,6 +476,7 @@
       Returns a stream writing this file. */
   public IndexOutput createOutput(String name) throws IOException {
     ensureOpen();
+    createDir();
     File file = new File(directory, name);
     if (file.exists() && !file.delete())          // delete existing, if any
       throw new IOException("Cannot overwrite: " + file);