LUCENE-1468: switch Directory.list() to Directory.listAll(), which does no filtering of returned array

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@723789 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -38,6 +38,14 @@ API Changes
    These methods can be used to avoid additional calls to doc(). 
    (Michael Busch)
 
+6. LUCENE-1468: Deprecate Directory.list(), which sometimes (in
+   FSDirectory) filters out files that don't look like index files, in
+   favor of new Directory.listAll(), which does no filtering.  Also,
+   listAll() will never return null; instead, it throws an IOException
+   (or subclass).  Specifically, FSDirectory.listAll() will throw the
+   newly added NoSuchDirectoryException if the directory does not
+   exist.  (Marcel Reutegger, Mike McCandless)
+
 Bug fixes
 
 1. LUCENE-1415: MultiPhraseQuery has incorrect hashCode() and equals()

contrib/benchmark/src/test/org/apache/lucene/benchmark/byTask/TestPerfTasksLogic.java

@@ -24,7 +24,6 @@ import java.io.BufferedReader;
 import java.util.List;
 import java.util.Iterator;
 
-import org.apache.lucene.benchmark.byTask.Benchmark;
 import org.apache.lucene.benchmark.byTask.feeds.DocData;
 import org.apache.lucene.benchmark.byTask.feeds.NoMoreDataException;
 import org.apache.lucene.benchmark.byTask.feeds.ReutersDocMaker;
@@ -712,7 +711,7 @@ public class TestPerfTasksLogic extends TestCase {
     ir.close();
 
     // Make sure we have 3 segments:
-    final String[] files = benchmark.getRunData().getDirectory().list();
+    final String[] files = benchmark.getRunData().getDirectory().listAll();
     int cfsCount = 0;
     for(int i=0;i<files.length;i++)
       if (files[i].endsWith(".cfs"))

src/java/org/apache/lucene/index/DirectoryIndexReader.java

@@ -480,9 +480,7 @@ abstract class DirectoryIndexReader extends IndexReader {
   /** @see IndexReader#listCommits */
   public static Collection listCommits(Directory dir) throws IOException {
 
-    final String[] files = dir.list();
+    final String[] files = dir.listAll();
-    if (files == null)
-      throw new IOException("cannot read directory " + dir + ": list() returned null");
 
     Collection commits = new ArrayList();
 

src/java/org/apache/lucene/index/IndexFileDeleter.java

@@ -146,9 +146,7 @@ final class IndexFileDeleter {
     long currentGen = segmentInfos.getGeneration();
     IndexFileNameFilter filter = IndexFileNameFilter.getFilter();
 
-    String[] files = directory.list();
+    String[] files = directory.listAll();
-    if (files == null)
-      throw new IOException("cannot read directory " + directory + ": list() returned null");
 
     CommitPoint currentCommitPoint = null;
 
@@ -306,9 +304,7 @@ final class IndexFileDeleter {
    * that segment.
    */
   public void refresh(String segmentName) throws IOException {
-    String[] files = directory.list();
+    String[] files = directory.listAll();
-    if (files == null)
-      throw new IOException("cannot read directory " + directory + ": list() returned null");
     IndexFileNameFilter filter = IndexFileNameFilter.getFilter();
     String segmentPrefix1;
     String segmentPrefix2;

src/java/org/apache/lucene/index/SegmentInfo.java

@@ -620,12 +620,11 @@ final class SegmentInfo {
       else
         prefix = name + "." + IndexFileNames.PLAIN_NORMS_EXTENSION;
       int prefixLength = prefix.length();
-      String[] allFiles = dir.list();
+      String[] allFiles = dir.listAll();
-      if (allFiles == null)
+      final IndexFileNameFilter filter = IndexFileNameFilter.getFilter();
-        throw new IOException("cannot read directory " + dir + ": list() returned null");
       for(int i=0;i<allFiles.length;i++) {
         String fileName = allFiles[i];
-        if (fileName.length() > prefixLength && Character.isDigit(fileName.charAt(prefixLength)) && fileName.startsWith(prefix)) {
+        if (filter.accept(null, fileName) && fileName.length() > prefixLength && Character.isDigit(fileName.charAt(prefixLength)) && fileName.startsWith(prefix)) {
           files.add(fileName);
         }
       }

src/java/org/apache/lucene/index/SegmentInfos.java

@@ -17,11 +17,13 @@ package org.apache.lucene.index;
  * limitations under the License.
  */
 
+import org.apache.lucene.store.FSDirectory;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IndexInput;
 import org.apache.lucene.store.IndexOutput;
 import org.apache.lucene.store.ChecksumIndexOutput;
 import org.apache.lucene.store.ChecksumIndexInput;
+import org.apache.lucene.store.NoSuchDirectoryException;
 
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -129,8 +131,11 @@ final class SegmentInfos extends Vector {
    * @param directory -- directory to search for the latest segments_N file
    */
   public static long getCurrentSegmentGeneration(Directory directory) throws IOException {
-    String[] files = directory.list();
+    try {
-    return getCurrentSegmentGeneration(files);
+      return getCurrentSegmentGeneration(directory.listAll());
+    } catch (NoSuchDirectoryException nsde) {
+      return -1;
+    }
   }
 
   /**
@@ -558,9 +563,9 @@ final class SegmentInfos extends Vector {
           long genA = -1;
 
           if (directory != null)
-            files = directory.list();
+            files = directory.listAll();
           else
-            files = fileDirectory.list();
+            files = FSDirectory.listAll(fileDirectory);
           
           if (files != null)
             genA = getCurrentSegmentGeneration(files);

src/java/org/apache/lucene/store/Directory.java

@@ -19,6 +19,8 @@ package org.apache.lucene.store;
 
 import java.io.IOException;
 
+import org.apache.lucene.index.IndexFileNameFilter;
+
 /** A Directory is a flat list of files.  Files may be written once, when they
  * are created.  Once a file is created it may only be opened for read, or
  * deleted.  Random access is permitted both when reading and writing.
@@ -43,14 +45,29 @@ public abstract class Directory {
    * this Directory instance). */
   protected LockFactory lockFactory;
 
-  /** Returns an array of strings, one for each file in the
+  /** @deprecated For some Directory implementations ({@link
-   * directory.  This method may return null (for example for
+   *  FSDirectory}, and its subclasses), this method
-   * {@link FSDirectory} if the underlying directory doesn't
+   *  silently filters its results to include only index
-   * exist in the filesystem or there are permissions
+   *  files.  Please use {@link #listAll} instead, which
-   * problems).*/
+   *  does no filtering. */
   public abstract String[] list()
        throws IOException;
 
+  /** Returns an array of strings, one for each file in the
+   *  directory.  Unlike {@link #list} this method does no
+   *  filtering of the contents in a directory, and it will
+   *  never return null (throws IOException instead).
+   *
+   *  Currently this method simply fallsback to {@link
+   *  #list} for Directory impls outside of Lucene's core &
+   *  contrib, but in 3.0 that method will be removed and
+   *  this method will become abstract. */
+  public String[] listAll()
+    throws IOException
+  {
+    return list();
+  }
+
   /** Returns true iff a file with the given name exists. */
   public abstract boolean fileExists(String name)
        throws IOException;
@@ -173,19 +190,26 @@ public abstract class Directory {
    * are undefined and you could easily hit a
    * FileNotFoundException.
    *
+   * <p><b>NOTE:</b> this method only copies files that look
+   * like index files (ie, have extensions matching the
+   * known extensions of index files).
+   *
    * @param src source directory
    * @param dest destination directory
    * @param closeDirSrc if <code>true</code>, call {@link #close()} method on source directory
    * @throws IOException
    */
   public static void copy(Directory src, Directory dest, boolean closeDirSrc) throws IOException {
-      final String[] files = src.list();
+    final String[] files = src.listAll();
 
-      if (files == null)
+    IndexFileNameFilter filter = IndexFileNameFilter.getFilter();
-        throw new IOException("cannot read directory " + src + ": list() returned null");
 
     byte[] buf = new byte[BufferedIndexOutput.BUFFER_SIZE];
     for (int i = 0; i < files.length; i++) {
+
+      if (!filter.accept(null, files[i]))
+        continue;
+
       IndexOutput os = null;
       IndexInput is = null;
       try {

src/java/org/apache/lucene/store/FSDirectory.java

@@ -18,6 +18,7 @@ package org.apache.lucene.store;
  */
 
 import java.io.File;
+import java.io.FilenameFilter;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
@@ -242,6 +243,7 @@ public class FSDirectory extends Directory {
     return dir;
   }
 
+  /** @deprecated */
   private void create() throws IOException {
     if (directory.exists()) {
       String[] files = directory.list(IndexFileNameFilter.getFilter());            // clear old files
@@ -265,9 +267,6 @@ public class FSDirectory extends Directory {
 
   final void createDir() throws IOException {
     if (!checked) {
-      if (directory.exists() && !directory.isDirectory())
-        throw new IOException(directory + " not a directory");
-
       if (!directory.exists())
         if (!directory.mkdirs())
           throw new IOException("Cannot create directory: " + directory);
@@ -304,6 +303,9 @@ public class FSDirectory extends Directory {
 
     directory = path;
 
+    if (directory.exists() && !directory.isDirectory())
+      throw new NoSuchDirectoryException("file '" + directory + "' exists but is not a directory");
+
     boolean doClearLockID = false;
 
     if (lockFactory == null) {
@@ -356,12 +358,46 @@ public class FSDirectory extends Directory {
     }
   }
 
-  /** Returns an array of strings, one for each Lucene index file in the directory. */
+  /** Lists all files (not subdirectories) in the
+   *  directory.  This method never returns null (throws
+   *  {@link IOException} instead).
+   *
+   *  @throws NoSuchDirectoryException if the directory
+   *   does not exist, or does exist but is not a
+   *   directory.
+   *  @throws IOException if list() returns null */
+  public static String[] listAll(File dir) throws IOException {
+    if (!dir.exists())
+      throw new NoSuchDirectoryException("directory '" + dir + "' does not exist");
+    else if (!dir.isDirectory())
+      throw new NoSuchDirectoryException("file '" + dir + "' exists but is not a directory");
+
+    // Exclude subdirs
+    String[] result = dir.list(new FilenameFilter() {
+        public boolean accept(File dir, String file) {
+          return !new File(dir, file).isDirectory();
+        }
+      });
+
+    if (result == null)
+      throw new IOException("directory '" + dir + "' exists and is a directory, but cannot be listed: list() returned null");
+
+    return result;
+  }
+
   public String[] list() {
     ensureOpen();
     return directory.list(IndexFileNameFilter.getFilter());
   }
 
+  /** Lists all files (not subdirectories) in the
+   * directory.
+   * @see #listAll(File) */
+  public String[] listAll() throws IOException {
+    ensureOpen();
+    return listAll(directory);
+  }
+
   /** Returns true iff a file with the given name exists. */
   public boolean fileExists(String name) {
     ensureOpen();

src/java/org/apache/lucene/store/NoSuchDirectoryException.java

@@ -0,0 +1,31 @@
+package org.apache.lucene.store;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.io.FileNotFoundException;
+
+/**
+ * This exception is thrown when you try to list a
+ * non-existent directory.
+ */
+
+public class NoSuchDirectoryException extends FileNotFoundException {
+  public NoSuchDirectoryException(String message) {
+    super(message);
+  }
+}

src/java/org/apache/lucene/store/RAMDirectory.java

@@ -95,8 +95,11 @@ public class RAMDirectory extends Directory implements Serializable {
     this(FSDirectory.getDirectory(dir), true);
   }
 
-  /** Returns an array of strings, one for each file in the directory. */
   public synchronized final String[] list() {
+    return listAll();
+  }
+
+  public synchronized final String[] listAll() {
     ensureOpen();
     Set fileNames = fileMap.keySet();
     String[] result = new String[fileNames.size()];

src/test/org/apache/lucene/index/TestBackwardsCompatibility.java

@@ -447,7 +447,7 @@ public class TestBackwardsCompatibility extends LuceneTestCase
                     "segments_3",
                     "segments.gen"};
 
-        String[] actual = dir.list();
+        String[] actual = dir.listAll();
         Arrays.sort(expected);
         Arrays.sort(actual);
         if (!Arrays.equals(expected, actual)) {

src/test/org/apache/lucene/index/TestDeletionPolicy.java

@@ -333,10 +333,10 @@ public class TestDeletionPolicy extends LuceneTestCase
           // should have orphan'd at least one index file.
           // Open & close a writer and assert that it
           // actually removed something:
-          int preCount = dir.list().length;
+          int preCount = dir.listAll().length;
           writer = new IndexWriter(dir, new WhitespaceAnalyzer(), false, policy, IndexWriter.MaxFieldLength.LIMITED);
           writer.close();
-          int postCount = dir.list().length;
+          int postCount = dir.listAll().length;
           assertTrue(postCount < preCount);
         }
       }

src/test/org/apache/lucene/index/TestFieldsReader.java

@@ -315,6 +315,9 @@ public class TestFieldsReader extends LuceneTestCase {
     public String[] list() throws IOException {
       return fsDir.list();
     }
+    public String[] listAll() throws IOException {
+      return fsDir.listAll();
+    }
     public boolean fileExists(String name) throws IOException {
       return fsDir.fileExists(name);
     }

src/test/org/apache/lucene/index/TestIndexFileDeleter.java

@@ -65,7 +65,7 @@ public class TestIndexFileDeleter extends LuceneTestCase
 
     // Now, artificially create an extra .del file & extra
     // .s0 file:
-    String[] files = dir.list();
+    String[] files = dir.listAll();
 
     /*
     for(int j=0;j<files.length;j++) {
@@ -142,14 +142,14 @@ public class TestIndexFileDeleter extends LuceneTestCase
     // Create a bogus cfs file shadowing a non-cfs segment:
     copyFile(dir, "_2.cfs", "_3.cfs");
 
-    String[] filesPre = dir.list();
+    String[] filesPre = dir.listAll();
 
     // Open & close a writer: it should delete the above 4
     // files and nothing more:
     writer = new IndexWriter(dir, new WhitespaceAnalyzer(), false, IndexWriter.MaxFieldLength.LIMITED);
     writer.close();
 
-    String[] files2 = dir.list();
+    String[] files2 = dir.listAll();
     dir.close();
 
     Arrays.sort(files);

src/test/org/apache/lucene/index/TestIndexReader.java

@@ -48,6 +48,7 @@ import org.apache.lucene.store.FSDirectory;
 import org.apache.lucene.store.LockObtainFailedException;
 import org.apache.lucene.store.MockRAMDirectory;
 import org.apache.lucene.store.RAMDirectory;
+import org.apache.lucene.store.NoSuchDirectoryException;
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util._TestUtil;
 
@@ -962,11 +963,11 @@ public class TestIndexReader extends LuceneTestCase
           // new IndexFileDeleter, have it delete
           // unreferenced files, then verify that in fact
           // no files were deleted:
-          String[] startFiles = dir.list();
+          String[] startFiles = dir.listAll();
           SegmentInfos infos = new SegmentInfos();
           infos.read(dir);
           new IndexFileDeleter(dir, new KeepOnlyLastCommitDeletionPolicy(), infos, null, null);
-          String[] endFiles = dir.list();
+          String[] endFiles = dir.listAll();
 
           Arrays.sort(startFiles);
           Arrays.sort(endFiles);
@@ -1520,6 +1521,7 @@ public class TestIndexReader extends LuceneTestCase
       }
     }
 
+
   // LUCENE-1474
   public void testIndexReader() throws Exception {
     Directory dir = new RAMDirectory();
@@ -1542,4 +1544,18 @@ public class TestIndexReader extends LuceneTestCase
     doc.add(new Field("id", id, Field.Store.YES, Field.Index.NOT_ANALYZED_NO_NORMS));
     return doc;
   }
+
+  // LUCENE-1468 -- make sure on attempting to open an
+  // IndexReader on a non-existent directory, you get a
+  // good exception
+  public void testNoDir() throws Throwable {
+    String tempDir = System.getProperty("java.io.tmpdir");
+    Directory dir = FSDirectory.getDirectory(new File(tempDir, "doesnotexist"), null);
+    try {
+      IndexReader.open(dir);
+      fail("did not hit expected exception");
+    } catch (NoSuchDirectoryException nsde) {
+      // expected
+    }
+  }
 }

src/test/org/apache/lucene/index/TestIndexReaderReopen.java

@@ -1051,7 +1051,7 @@ public class TestIndexReaderReopen extends LuceneTestCase {
     dir1.close();
 
     try {
-      dir1.list();
+      dir1.listAll();
       fail("did not hit AlreadyClosedException");
     } catch (AlreadyClosedException ace) {
       // expected

src/test/org/apache/lucene/index/TestIndexWriter.java

@@ -170,7 +170,7 @@ public class TestIndexWriter extends LuceneTestCase
           addDocWithIndex(writer, 25*i+j);
         }
         writer.close();
-        String[] files = dirs[i].list();
+        String[] files = dirs[i].listAll();
         for(int j=0;j<files.length;j++) {
           inputDiskUsage += dirs[i].fileLength(files[j]);
         }
@@ -207,11 +207,11 @@ public class TestIndexWriter extends LuceneTestCase
       // succeed and index should show all documents were
       // added.
 
-      // String[] files = startDir.list();
+      // String[] files = startDir.listAll();
       long diskUsage = startDir.sizeInBytes();
 
       long startDiskUsage = 0;
-      String[] files = startDir.list();
+      String[] files = startDir.listAll();
       for(int i=0;i<files.length;i++) {
         startDiskUsage += startDir.fileLength(files[i]);
       }
@@ -539,11 +539,11 @@ public class TestIndexWriter extends LuceneTestCase
     }                                               
 
     public static void assertNoUnreferencedFiles(Directory dir, String message) throws IOException {
-      String[] startFiles = dir.list();
+      String[] startFiles = dir.listAll();
       SegmentInfos infos = new SegmentInfos();
       infos.read(dir);
       new IndexFileDeleter(dir, new KeepOnlyLastCommitDeletionPolicy(), infos, null, null);
-      String[] endFiles = dir.list();
+      String[] endFiles = dir.listAll();
 
       Arrays.sort(startFiles);
       Arrays.sort(endFiles);
@@ -708,7 +708,7 @@ public class TestIndexWriter extends LuceneTestCase
       writer.close();
 
       long startDiskUsage = 0;
-      String[] files = dir.list();
+      String[] files = dir.listAll();
       for(int i=0;i<files.length;i++) {
         startDiskUsage += dir.fileLength(files[i]);
       }
@@ -988,7 +988,7 @@ public class TestIndexWriter extends LuceneTestCase
         long gen = SegmentInfos.getCurrentSegmentGeneration(dir);
         assertTrue("segment generation should be > 1 but got " + gen, gen > 1);
 
-        String[] files = dir.list();
+        String[] files = dir.listAll();
         for(int i=0;i<files.length;i++) {
           if (files[i].endsWith(".cfs")) {
             dir.deleteFile(files[i]);
@@ -1276,12 +1276,12 @@ public class TestIndexWriter extends LuceneTestCase
       RAMDirectory dir = new RAMDirectory();      
       IndexWriter writer  = new IndexWriter(dir, new WhitespaceAnalyzer(), true, IndexWriter.MaxFieldLength.LIMITED);
       writer.setRAMBufferSizeMB(0.000001);
-      int lastNumFile = dir.list().length;
+      int lastNumFile = dir.listAll().length;
       for(int j=0;j<9;j++) {
         Document doc = new Document();
         doc.add(new Field("field", "aaa" + j, Field.Store.YES, Field.Index.ANALYZED));
         writer.addDocument(doc);
-        int numFile = dir.list().length;
+        int numFile = dir.listAll().length;
         // Verify that with a tiny RAM buffer we see new
         // segment after every doc
         assertTrue(numFile > lastNumFile);
@@ -4254,4 +4254,31 @@ public class TestIndexWriter extends LuceneTestCase
     r.close();
     dir.close();
   }
+
+  // LUCENE-1468 -- make sure opening an IndexWriter with
+  // create=true does not remove non-index files
+  
+  public void testOtherFiles() throws Throwable {
+    File indexDir = new File(System.getProperty("tempDir"), "otherfiles");
+    Directory dir = new FSDirectory(indexDir, null);
+    try {
+      // Create my own random file:
+
+      IndexOutput out = dir.createOutput("myrandomfile");
+      out.writeByte((byte) 42);
+      out.close();
+
+      new IndexWriter(dir, new WhitespaceAnalyzer(), true, IndexWriter.MaxFieldLength.LIMITED).close();
+
+      assertTrue(dir.fileExists("myrandomfile"));
+
+      // Make sure this does not copy myrandomfile:
+      Directory dir2 = new RAMDirectory(dir);
+      assertTrue(!dir2.fileExists("myrandomfile"));
+
+    } finally {
+      dir.close();
+      _TestUtil.rmDir(indexDir);
+    }
+  }
 }

src/test/org/apache/lucene/index/TestIndexWriterDelete.java

@@ -668,11 +668,11 @@ public class TestIndexWriterDelete extends LuceneTestCase {
         }
       }
 
-      String[] startFiles = dir.list();
+      String[] startFiles = dir.listAll();
       SegmentInfos infos = new SegmentInfos();
       infos.read(dir);
       new IndexFileDeleter(dir, new KeepOnlyLastCommitDeletionPolicy(), infos, null, null);
-      String[] endFiles = dir.list();
+      String[] endFiles = dir.listAll();
 
       if (!Arrays.equals(startFiles, endFiles)) {
         fail("docswriter abort() failed to delete unreferenced files:\n  before delete:\n    "

src/test/org/apache/lucene/index/TestIndexWriterMergePolicy.java

@@ -239,7 +239,7 @@ public class TestIndexWriterMergePolicy extends LuceneTestCase {
       assertTrue(numSegments < mergeFactor);
     }
 
-    String[] files = writer.getDirectory().list();
+    String[] files = writer.getDirectory().listAll();
     int segmentCfsCount = 0;
     for (int i = 0; i < files.length; i++) {
       if (files[i].endsWith(".cfs")) {
@@ -249,6 +249,7 @@ public class TestIndexWriterMergePolicy extends LuceneTestCase {
     assertEquals(segmentCount, segmentCfsCount);
   }
 
+  /*
   private void printSegmentDocCounts(IndexWriter writer) {
     int segmentCount = writer.getSegmentCount();
     System.out.println("" + segmentCount + " segments total");
@@ -257,4 +258,5 @@ public class TestIndexWriterMergePolicy extends LuceneTestCase {
           + " docs");
     }
   }
+  */
 }

src/test/org/apache/lucene/index/TestOmitTf.java

@@ -197,7 +197,7 @@ public class TestOmitTf extends LuceneTestCase {
   }
 
   private void assertNoPrx(Directory dir) throws Throwable {
-    final String[] files = dir.list();
+    final String[] files = dir.listAll();
     for(int i=0;i<files.length;i++)
       assertFalse(files[i].endsWith(".prx"));
   }

src/test/org/apache/lucene/store/TestBufferedIndexInput.java

@@ -271,6 +271,11 @@ public class TestBufferedIndexInput extends LuceneTestCase {
       {
         return dir.list();
       }
+      public String[] listAll()
+        throws IOException
+      {
+        return dir.listAll();
+      }
 
       public long fileLength(String name) throws IOException {
         return dir.fileLength(name);

src/test/org/apache/lucene/store/TestDirectory.java

@@ -21,6 +21,8 @@ import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util._TestUtil;
 
 import java.io.File;
+import java.io.IOException;
+import java.util.Arrays;
 
 public class TestDirectory extends LuceneTestCase {
 
@@ -128,5 +130,60 @@ public class TestDirectory extends LuceneTestCase {
       _TestUtil.rmDir(path);
     }
   }
+
+  // LUCENE-1468
+  public void testRAMDirectoryFilter() throws IOException {
+    checkDirectoryFilter(new RAMDirectory());
+  }
+
+  // LUCENE-1468
+  public void testFSDirectoryFilter() throws IOException {
+    checkDirectoryFilter(FSDirectory.getDirectory("test"));
+  }
+
+  // LUCENE-1468
+  private void checkDirectoryFilter(Directory dir) throws IOException {
+    String name = "file";
+    try {
+      dir.createOutput(name).close();
+      assertTrue(dir.fileExists(name));
+      assertTrue(Arrays.asList(dir.listAll()).contains(name));
+    } finally {
+      dir.close();
+    }
+  }
+
+  // LUCENE-1468
+  public void testCopySubdir() throws Throwable {
+    File path = new File(System.getProperty("tempDir"), "testsubdir");
+    try {
+      path.mkdirs();
+      new File(path, "subdir").mkdirs();
+      Directory fsDir = new FSDirectory(path, null);
+      assertEquals(0, new RAMDirectory(fsDir).listAll().length);
+    } finally {
+      _TestUtil.rmDir(path);
+    }
+  }
+
+  // LUCENE-1468
+  public void testNotDirectory() throws Throwable {
+    File path = new File(System.getProperty("tempDir"), "testnotdir");
+    Directory fsDir = new FSDirectory(path, null);
+    try {
+      IndexOutput out = fsDir.createOutput("afile");
+      out.close();
+      assertTrue(fsDir.fileExists("afile"));
+      try {
+        new FSDirectory(new File(path, "afile"), null);
+        fail("did not hit expected exception");
+      } catch (NoSuchDirectoryException nsde) {
+        // Expected
+      }
+    } finally {
+      fsDir.close();
+      _TestUtil.rmDir(path);
+    }
+  }
 }