Index: lucene/CHANGES.txt
===================================================================
--- lucene/CHANGES.txt	(revision 932917)
+++ lucene/CHANGES.txt	(working copy)
@@ -105,6 +105,12 @@
   of incrementToken(), tokenStream(), and reusableTokenStream().
   (Uwe Schindler, Robert Muir)
 
+* LUCENE-2386: IndexWriter no longer performs an empty commit upon new index
+  creation. Previously, if you passed an empty Directory and set OpenMode to
+  CREATE*, IndexWriter would make a first empty commit. If you need that 
+  behavior you can call writer.commit() immediately after you create it.
+  (Shai Erera, Mike McCandless)
+  
 Changes in runtime behavior
 
 * LUCENE-1923: Made IndexReader.toString() produce something
Index: lucene/backwards/src/test/org/apache/lucene/TestSnapshotDeletionPolicy.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/TestSnapshotDeletionPolicy.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/TestSnapshotDeletionPolicy.java	(working copy)
@@ -113,7 +113,7 @@
 
     SnapshotDeletionPolicy dp = new SnapshotDeletionPolicy(new KeepOnlyLastCommitDeletionPolicy());
     final IndexWriter writer = new IndexWriter(dir, new StandardAnalyzer(org.apache.lucene.util.Version.LUCENE_CURRENT), dp, IndexWriter.MaxFieldLength.UNLIMITED);
-
+    writer.commit();
     // Force frequent flushes
     writer.setMaxBufferedDocs(2);
 
Index: lucene/backwards/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java	(working copy)
@@ -553,7 +553,7 @@
       expected = new String[] {"_0.cfs",
                                "_0_1.del",
                                "_0_1.s" + contentFieldIndex,
-                               "segments_3",
+                               "segments_2",
                                "segments.gen"};
 
       String[] actual = dir.listAll();
Index: lucene/backwards/src/test/org/apache/lucene/index/TestCrash.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestCrash.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestCrash.java	(working copy)
@@ -25,20 +25,24 @@
 import org.apache.lucene.store.NoLockFactory;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
+import org.apache.lucene.index.IndexWriter;
 
 public class TestCrash extends LuceneTestCase {
 
-  private IndexWriter initIndex() throws IOException {
-    return initIndex(new MockRAMDirectory());
+  private IndexWriter initIndex(boolean initialCommit) throws IOException {
+    return initIndex(new MockRAMDirectory(), initialCommit);
   }
 
-  private IndexWriter initIndex(MockRAMDirectory dir) throws IOException {
+  private IndexWriter initIndex(MockRAMDirectory dir, boolean initialCommit) throws IOException {
     dir.setLockFactory(NoLockFactory.getNoLockFactory());
 
     IndexWriter writer  = new IndexWriter(dir, new WhitespaceAnalyzer(), IndexWriter.MaxFieldLength.UNLIMITED);
     //writer.setMaxBufferedDocs(2);
     writer.setMaxBufferedDocs(10);
     ((ConcurrentMergeScheduler) writer.getMergeScheduler()).setSuppressExceptions();
+    if (initialCommit) {
+      writer.commit();
+    }
 
     Document doc = new Document();
     doc.add(new Field("content", "aaa", Field.Store.YES, Field.Index.ANALYZED));
@@ -58,7 +62,7 @@
   }
 
   public void testCrashWhileIndexing() throws IOException {
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(true);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
     crash(writer);
     IndexReader reader = IndexReader.open(dir, false);
@@ -66,11 +70,11 @@
   }
 
   public void testWriterAfterCrash() throws IOException {
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(true);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
     dir.setPreventDoubleWrite(false);
     crash(writer);
-    writer = initIndex(dir);
+    writer = initIndex(dir, false);
     writer.close();
 
     IndexReader reader = IndexReader.open(dir, false);
@@ -78,10 +82,10 @@
   }
 
   public void testCrashAfterReopen() throws IOException {
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(false);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
     writer.close();
-    writer = initIndex(dir);
+    writer = initIndex(dir, false);
     assertEquals(314, writer.maxDoc());
     crash(writer);
 
@@ -100,7 +104,7 @@
 
   public void testCrashAfterClose() throws IOException {
     
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(false);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
 
     writer.close();
@@ -119,7 +123,7 @@
 
   public void testCrashAfterCloseNoWait() throws IOException {
     
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(false);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
 
     writer.close(false);
@@ -138,7 +142,7 @@
 
   public void testCrashReaderDeletes() throws IOException {
     
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(false);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
 
     writer.close(false);
@@ -159,7 +163,7 @@
 
   public void testCrashReaderDeletesAfterClose() throws IOException {
     
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(false);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
 
     writer.close(false);
Index: lucene/backwards/src/test/org/apache/lucene/index/TestDeletionPolicy.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestDeletionPolicy.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestDeletionPolicy.java	(working copy)
@@ -290,7 +290,7 @@
       writer.optimize();
       writer.close();
 
-      assertEquals(2, policy.numOnInit);
+      assertEquals(1, policy.numOnInit);
 
       // If we are not auto committing then there should
       // be exactly 2 commits (one per close above):
@@ -298,8 +298,8 @@
 
       // Test listCommits
       Collection commits = IndexReader.listCommits(dir);
-      // 1 from opening writer + 2 from closing writer
-      assertEquals(3, commits.size());
+      // 2 from closing writer
+      assertEquals(2, commits.size());
 
       Iterator it = commits.iterator();
       // Make sure we can open a reader on each commit:
@@ -357,7 +357,7 @@
     writer.close();
 
     Collection commits = IndexReader.listCommits(dir);
-    assertEquals(6, commits.size());
+    assertEquals(5, commits.size());
     IndexCommit lastCommit = null;
     Iterator it = commits.iterator();
     while(it.hasNext()) {
@@ -374,7 +374,7 @@
     writer.optimize();
     writer.close();
 
-    assertEquals(7, IndexReader.listCommits(dir).size());
+    assertEquals(6, IndexReader.listCommits(dir).size());
 
     // Now open writer on the commit just before optimize:
     writer = new IndexWriter(dir, new WhitespaceAnalyzer(), policy, IndexWriter.MaxFieldLength.LIMITED, lastCommit);
@@ -395,7 +395,7 @@
     writer.close();
 
     // Now 8 because we made another commit
-    assertEquals(8, IndexReader.listCommits(dir).size());
+    assertEquals(7, IndexReader.listCommits(dir).size());
     
     r = IndexReader.open(dir, true);
     // Not optimized because we rolled it back, and now only
@@ -465,7 +465,7 @@
       writer.optimize();
       writer.close();
 
-      assertEquals(2, policy.numOnInit);
+      assertEquals(1, policy.numOnInit);
       // If we are not auto committing then there should
       // be exactly 2 commits (one per close above):
       assertEquals(2, policy.numOnCommit);
@@ -506,7 +506,7 @@
       }
 
       assertTrue(policy.numDelete > 0);
-      assertEquals(N+1, policy.numOnInit);
+      assertEquals(N, policy.numOnInit);
       assertEquals(N+1, policy.numOnCommit);
 
       // Simplistic check: just verify only the past N segments_N's still
@@ -580,8 +580,8 @@
       // this is a commit
       writer.close();
 
-      assertEquals(2*(N+2), policy.numOnInit);
-      assertEquals(2*(N+2)-1, policy.numOnCommit);
+      assertEquals(2*(N+1)+1, policy.numOnInit);
+      assertEquals(2*(N+2), policy.numOnCommit);
 
       IndexSearcher searcher = new IndexSearcher(dir, false);
       ScoreDoc[] hits = searcher.search(query, null, 1000).scoreDocs;
@@ -678,8 +678,8 @@
         writer.close();
       }
 
-      assertEquals(1+3*(N+1), policy.numOnInit);
-      assertEquals(3*(N+1), policy.numOnCommit);
+      assertEquals(3*(N+1), policy.numOnInit);
+      assertEquals(3*(N+1)+1, policy.numOnCommit);
 
       IndexSearcher searcher = new IndexSearcher(dir, false);
       ScoreDoc[] hits = searcher.search(query, null, 1000).scoreDocs;
Index: lucene/backwards/src/test/org/apache/lucene/index/TestIndexFileDeleter.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestIndexFileDeleter.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestIndexFileDeleter.java	(working copy)
@@ -136,11 +136,11 @@
     copyFile(dir, "_0.cfs", "deletable");
 
     // Create some old segments file:
-    copyFile(dir, "segments_3", "segments");
-    copyFile(dir, "segments_3", "segments_2");
+    copyFile(dir, "segments_2", "segments");
+    copyFile(dir, "segments_2", "segments_1");
 
     // Create a bogus cfs file shadowing a non-cfs segment:
-    copyFile(dir, "_2.cfs", "_3.cfs");
+    copyFile(dir, "_1.cfs", "_2.cfs");
 
     String[] filesPre = dir.listAll();
 
Index: lucene/backwards/src/test/org/apache/lucene/index/TestIndexReader.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestIndexReader.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestIndexReader.java	(working copy)
@@ -39,6 +39,7 @@
 import org.apache.lucene.document.FieldSelector;
 import org.apache.lucene.document.Fieldable;
 import org.apache.lucene.document.SetBasedFieldSelector;
+import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexReader.FieldOption;
 import org.apache.lucene.search.FieldCache;
 import org.apache.lucene.search.IndexSearcher;
@@ -474,6 +475,7 @@
 
         //  add 11 documents with term : aaa
         writer  = new IndexWriter(dir, new WhitespaceAnalyzer(), true, IndexWriter.MaxFieldLength.LIMITED);
+        writer.commit();
         for (int i = 0; i < 11; i++)
         {
             addDoc(writer, searchTerm.text());
@@ -1765,6 +1767,7 @@
   public void testPrepareCommitIsCurrent() throws Throwable {
     Directory dir = new MockRAMDirectory();
     IndexWriter writer = new IndexWriter(dir, new WhitespaceAnalyzer(), IndexWriter.MaxFieldLength.UNLIMITED);
+    writer.commit();
     Document doc = new Document();
     writer.addDocument(doc);
     IndexReader r = IndexReader.open(dir, true);
Index: lucene/backwards/src/test/org/apache/lucene/index/TestIndexReaderReopen.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestIndexReaderReopen.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestIndexReaderReopen.java	(working copy)
@@ -36,6 +36,7 @@
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.Field.Index;
 import org.apache.lucene.document.Field.Store;
+import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexWriter.MaxFieldLength;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.ScoreDoc;
@@ -172,6 +173,7 @@
   private void doTestReopenWithCommit (Directory dir, boolean withReopen) throws IOException {
     IndexWriter iwriter = new IndexWriter(dir, new KeywordAnalyzer(), true, MaxFieldLength.LIMITED);
     iwriter.setMergeScheduler(new SerialMergeScheduler());
+    iwriter.commit();
     IndexReader reader = IndexReader.open(dir, false);
     try {
       int M = 3;
Index: lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriter.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriter.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriter.java	(working copy)
@@ -47,6 +47,7 @@
 import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
+import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.PhraseQuery;
 import org.apache.lucene.search.Query;
@@ -783,7 +784,7 @@
         writer.close();
 
         long gen = SegmentInfos.getCurrentSegmentGeneration(dir);
-        assertTrue("segment generation should be > 1 but got " + gen, gen > 1);
+        assertTrue("segment generation should be > 0 but got " + gen, gen > 0);
 
         // Make the next segments file, with last byte
         // missing, to simulate a writer that crashed while
@@ -843,7 +844,7 @@
         writer.close();
 
         long gen = SegmentInfos.getCurrentSegmentGeneration(dir);
-        assertTrue("segment generation should be > 1 but got " + gen, gen > 1);
+        assertTrue("segment generation should be > 0 but got " + gen, gen > 0);
 
         String fileNameIn = SegmentInfos.getCurrentSegmentFileName(dir);
         String fileNameOut = IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS,
@@ -908,7 +909,7 @@
         writer.close();
 
         long gen = SegmentInfos.getCurrentSegmentGeneration(dir);
-        assertTrue("segment generation should be > 1 but got " + gen, gen > 1);
+        assertTrue("segment generation should be > 0 but got " + gen, gen > 0);
 
         String[] files = dir.listAll();
         for(int i=0;i<files.length;i++) {
@@ -2324,7 +2325,7 @@
   public void testImmediateDiskFull() throws IOException {
     MockRAMDirectory dir = new MockRAMDirectory();
     IndexWriter writer = new IndexWriter(dir, new WhitespaceAnalyzer(), IndexWriter.MaxFieldLength.LIMITED);
-    dir.setMaxSizeInBytes(dir.getRecomputedActualSizeInBytes());
+    dir.setMaxSizeInBytes(Math.max(1, dir.getRecomputedActualSizeInBytes()));
     writer.setMaxBufferedDocs(2);
     final Document doc = new Document();
     doc.add(new Field("field", "aaa bbb ccc ddd eee fff ggg hhh iii jjj", Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS));
@@ -2647,7 +2648,7 @@
     writer.close();
 
     long gen = SegmentInfos.getCurrentSegmentGeneration(dir);
-    assertTrue("segment generation should be > 1 but got " + gen, gen > 1);
+    assertTrue("segment generation should be > 0 but got " + gen, gen > 0);
 
     final String segmentsFileName = SegmentInfos.getCurrentSegmentFileName(dir);
     IndexInput in = dir.openInput(segmentsFileName);
@@ -2675,7 +2676,8 @@
     IndexWriter writer  = new IndexWriter(dir, new WhitespaceAnalyzer(), IndexWriter.MaxFieldLength.LIMITED);
     writer.setMaxBufferedDocs(2);
     writer.setMergeFactor(5);
-
+    writer.commit();
+    
     for (int i = 0; i < 23; i++)
       addDoc(writer);
 
@@ -3542,7 +3544,8 @@
     IndexWriter writer = new IndexWriter(dir, new WhitespaceAnalyzer(), IndexWriter.MaxFieldLength.LIMITED);
     writer.setMaxBufferedDocs(2);
     writer.setMergeFactor(5);
-
+    writer.commit();
+    
     for (int i = 0; i < 23; i++)
       addDoc(writer);
 
@@ -3595,7 +3598,8 @@
 
     writer.setMaxBufferedDocs(2);
     writer.setMergeFactor(5);
-
+    writer.commit();
+    
     for (int i = 0; i < 23; i++)
       addDoc(writer);
 
@@ -3679,6 +3683,7 @@
 
       dir2 = new MockRAMDirectory();
       writer2 = new IndexWriter(dir2, new WhitespaceAnalyzer(), IndexWriter.MaxFieldLength.LIMITED);
+      writer2.commit();
       cms = (ConcurrentMergeScheduler) writer2.getMergeScheduler();
 
       readers = new IndexReader[NUM_COPY];
Index: lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriterDelete.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriterDelete.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriterDelete.java	(working copy)
@@ -23,6 +23,7 @@
 import org.apache.lucene.analysis.WhitespaceAnalyzer;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
+import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.search.TermQuery;
@@ -764,7 +765,7 @@
     MockRAMDirectory dir = new MockRAMDirectory();
     IndexWriter modifier = new IndexWriter(dir,
                                            new WhitespaceAnalyzer(), true, IndexWriter.MaxFieldLength.UNLIMITED);
-
+    modifier.commit();
     dir.failOn(failure.reset());
 
     for (int i = 0; i < keywords.length; i++) {
Index: lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriterExceptions.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriterExceptions.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriterExceptions.java	(working copy)
@@ -138,7 +138,8 @@
     ((ConcurrentMergeScheduler) writer.getMergeScheduler()).setSuppressExceptions();
     //writer.setMaxBufferedDocs(10);
     writer.setRAMBufferSizeMB(0.1);
-
+    writer.commit();
+    
     if (DEBUG)
       writer.setInfoStream(System.out);
 
@@ -176,6 +177,7 @@
     ((ConcurrentMergeScheduler) writer.getMergeScheduler()).setSuppressExceptions();
     //writer.setMaxBufferedDocs(10);
     writer.setRAMBufferSizeMB(0.2);
+    writer.commit();
 
     if (DEBUG)
       writer.setInfoStream(System.out);
Index: lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriterReader.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriterReader.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestIndexWriterReader.java	(working copy)
@@ -30,6 +30,7 @@
 import org.apache.lucene.document.Field.Index;
 import org.apache.lucene.document.Field.Store;
 import org.apache.lucene.document.Field.TermVector;
+import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.search.TermQuery;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.Query;
@@ -642,6 +643,7 @@
     Directory dir1 = new MockRAMDirectory();
     IndexWriter writer = new IndexWriter(dir1, new WhitespaceAnalyzer(),
                                          IndexWriter.MaxFieldLength.LIMITED);
+    writer.commit();
     writer.setInfoStream(infoStream);
 
     // create the index
Index: lucene/backwards/src/test/org/apache/lucene/index/TestStressIndexing.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestStressIndexing.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestStressIndexing.java	(working copy)
@@ -19,6 +19,7 @@
 import org.apache.lucene.util.*;
 import org.apache.lucene.store.*;
 import org.apache.lucene.document.*;
+import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.analysis.*;
 import org.apache.lucene.search.*;
 import org.apache.lucene.queryParser.*;
@@ -121,7 +122,7 @@
   */
   public void runStressTest(Directory directory, MergeScheduler mergeScheduler) throws Exception {
     IndexWriter modifier = new IndexWriter(directory, ANALYZER, true, IndexWriter.MaxFieldLength.UNLIMITED);
-
+    modifier.commit();
     modifier.setMaxBufferedDocs(10);
 
     TimedThread[] threads = new TimedThread[4];
Index: lucene/backwards/src/test/org/apache/lucene/index/TestStressIndexing2.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/index/TestStressIndexing2.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/index/TestStressIndexing2.java	(working copy)
@@ -16,6 +16,7 @@
 
 import org.apache.lucene.store.*;
 import org.apache.lucene.document.*;
+import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.analysis.*;
 
 import org.apache.lucene.util.LuceneTestCase;
@@ -124,6 +125,7 @@
   public DocsAndWriter indexRandomIWReader(int nThreads, int iterations, int range, Directory dir) throws IOException, InterruptedException {
     Map docs = new HashMap();
     IndexWriter w = new MockIndexWriter(dir, new WhitespaceAnalyzer(), true, IndexWriter.MaxFieldLength.UNLIMITED);
+    w.commit();
     w.setUseCompoundFile(false);
 
     /***
Index: lucene/backwards/src/test/org/apache/lucene/store/TestBufferedIndexInput.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/store/TestBufferedIndexInput.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/store/TestBufferedIndexInput.java	(working copy)
@@ -241,6 +241,7 @@
 
     public void testSetBufferSize() throws IOException {
       File indexDir = new File(System.getProperty("tempDir"), "testSetBufferSize");
+      indexDir.mkdirs(); // required for this MockFSDir since we don't commit on IW creation anymore.
       MockFSDirectory dir = new MockFSDirectory(indexDir, newRandom());
       try {
         IndexWriter writer = new IndexWriter(dir, new WhitespaceAnalyzer(), true, IndexWriter.MaxFieldLength.LIMITED);
Index: lucene/backwards/src/test/org/apache/lucene/store/TestLockFactory.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/store/TestLockFactory.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/store/TestLockFactory.java	(working copy)
@@ -85,7 +85,8 @@
 
         IndexWriter writer = new IndexWriter(dir, new WhitespaceAnalyzer(), true,
                                              IndexWriter.MaxFieldLength.LIMITED);
-
+        writer.commit(); // required so the second open succeed
+        
         // Create a 2nd IndexWriter.  This is normally not allowed but it should run through since we're not
         // using any locks:
         IndexWriter writer2 = null;
Index: lucene/backwards/src/test/org/apache/lucene/store/TestWindowsMMap.java
===================================================================
--- lucene/backwards/src/test/org/apache/lucene/store/TestWindowsMMap.java	(revision 932917)
+++ lucene/backwards/src/test/org/apache/lucene/store/TestWindowsMMap.java	(working copy)
@@ -64,14 +64,18 @@
     new File(System.getProperty("tempDir"),"testLuceneMmap").getAbsolutePath();
 
   public void testMmapIndex() throws Exception {
-    FSDirectory storeDirectory;
-    storeDirectory = new MMapDirectory(new File(storePathname), null);
+    // sometimes the directory is not cleaned by rmDir, because on Windows it
+    // may take some time until the files are finally dereferenced. So clean the
+    // directory up front, or otherwise new IndexWriter will fail.
+    rmDir(new File(storePathname));
+    FSDirectory storeDirectory = new MMapDirectory(new File(storePathname), null);
 
     // plan to add a set of useful stopwords, consider changing some of the
     // interior filters.
     StandardAnalyzer analyzer = new StandardAnalyzer(org.apache.lucene.util.Version.LUCENE_CURRENT, Collections.emptySet());
     // TODO: something about lock timeouts and leftover locks.
     IndexWriter writer = new IndexWriter(storeDirectory, analyzer, true, IndexWriter.MaxFieldLength.LIMITED);
+    writer.commit();
     IndexSearcher searcher = new IndexSearcher(storeDirectory, true);
     
     for(int dx = 0; dx < 1000; dx ++) {
@@ -83,14 +87,16 @@
     
     searcher.close();
     writer.close();
-                rmDir(new File(storePathname));
+    rmDir(new File(storePathname));
   }
 
-        private void rmDir(File dir) {
-          File[] files = dir.listFiles();
-          for (int i = 0; i < files.length; i++) {
-            files[i].delete();
-          }
-          dir.delete();
-        }
+  private void rmDir(File dir) {
+    if (!dir.exists()) {
+      return;
+    }
+    for (File file : dir.listFiles()) {
+      file.delete();
+    }
+    dir.delete();
+  }
 }
Index: lucene/contrib/xml-query-parser/src/test/org/apache/lucene/xmlparser/builders/TestNumericRangeFilterBuilder.java
===================================================================
--- lucene/contrib/xml-query-parser/src/test/org/apache/lucene/xmlparser/builders/TestNumericRangeFilterBuilder.java	(revision 932917)
+++ lucene/contrib/xml-query-parser/src/test/org/apache/lucene/xmlparser/builders/TestNumericRangeFilterBuilder.java	(working copy)
@@ -29,6 +29,7 @@
 
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.IndexWriter;
+import org.apache.lucene.index.IndexWriterConfig;
 import org.apache.lucene.index.IndexWriter.MaxFieldLength;
 import org.apache.lucene.search.Filter;
 import org.apache.lucene.search.NumericRangeFilter;
@@ -62,7 +63,8 @@
 		Filter filter = filterBuilder.getFilter(doc.getDocumentElement());
 
 		RAMDirectory ramDir = new RAMDirectory();
-		IndexWriter writer = new IndexWriter(ramDir, null, MaxFieldLength.UNLIMITED);
+		IndexWriter writer = new IndexWriter(ramDir, new IndexWriterConfig(TEST_VERSION_CURRENT, null));
+		writer.commit();
 		try
 		{
 			IndexReader reader = IndexReader.open(ramDir, true);
Index: lucene/src/java/org/apache/lucene/index/DirectoryReader.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/DirectoryReader.java	(revision 932917)
+++ lucene/src/java/org/apache/lucene/index/DirectoryReader.java	(working copy)
@@ -1030,7 +1030,11 @@
     Collection<IndexCommit> commits = new ArrayList<IndexCommit>();
 
     SegmentInfos latest = new SegmentInfos();
-    latest.read(dir, codecs);
+    try {
+      latest.read(dir, codecs);
+    } catch (IndexNotFoundException e) {
+      return Collections.emptyList();
+    }
     final long currentGen = latest.getGeneration();
 
     commits.add(new ReaderCommit(latest, dir));
Index: lucene/src/java/org/apache/lucene/index/IndexFileDeleter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/IndexFileDeleter.java	(revision 932917)
+++ lucene/src/java/org/apache/lucene/index/IndexFileDeleter.java	(working copy)
@@ -31,6 +31,7 @@
 
 import org.apache.lucene.index.codecs.CodecProvider;
 import org.apache.lucene.store.Directory;
+import org.apache.lucene.store.NoSuchDirectoryException;
 
 /*
  * This class keeps track of each SegmentInfos instance that
@@ -144,58 +145,62 @@
     long currentGen = segmentInfos.getGeneration();
     indexFilenameFilter = new IndexFileNameFilter(codecs);
     
-    String[] files = directory.listAll();
-
     CommitPoint currentCommitPoint = null;
+    boolean seenIndexFiles = false;
+    try {
+      for (String fileName : directory.listAll()) {
 
-    for(int i=0;i<files.length;i++) {
+        if ((indexFilenameFilter.accept(null, fileName)) && !fileName.endsWith("write.lock") && !fileName.equals(IndexFileNames.SEGMENTS_GEN)) {
+          seenIndexFiles = true;
+          
+          // Add this file to refCounts with initial count 0:
+          getRefCount(fileName);
 
-      String fileName = files[i];
+          if (fileName.startsWith(IndexFileNames.SEGMENTS)) {
 
-      if ((indexFilenameFilter.accept(null, fileName)) && !fileName.endsWith("write.lock") && !fileName.equals(IndexFileNames.SEGMENTS_GEN)) {
-
-        // Add this file to refCounts with initial count 0:
-        getRefCount(fileName);
-
-        if (fileName.startsWith(IndexFileNames.SEGMENTS)) {
-
-          // This is a commit (segments or segments_N), and
-          // it's valid (<= the max gen).  Load it, then
-          // incref all files it refers to:
-          if (SegmentInfos.generationFromSegmentsFileName(fileName) <= currentGen) {
-            if (infoStream != null) {
-              message("init: load commit \"" + fileName + "\"");
-            }
-            SegmentInfos sis = new SegmentInfos();
-            try {
-              sis.read(directory, fileName, codecs);
-            } catch (FileNotFoundException e) {
-              // LUCENE-948: on NFS (and maybe others), if
-              // you have writers switching back and forth
-              // between machines, it's very likely that the
-              // dir listing will be stale and will claim a
-              // file segments_X exists when in fact it
-              // doesn't.  So, we catch this and handle it
-              // as if the file does not exist
+            // This is a commit (segments or segments_N), and
+            // it's valid (<= the max gen).  Load it, then
+            // incref all files it refers to:
+            if (SegmentInfos.generationFromSegmentsFileName(fileName) <= currentGen) {
               if (infoStream != null) {
-                message("init: hit FileNotFoundException when loading commit \"" + fileName + "\"; skipping this commit point");
+                message("init: load commit \"" + fileName + "\"");
               }
-              sis = null;
-            }
-            if (sis != null) {
-              CommitPoint commitPoint = new CommitPoint(commitsToDelete, directory, sis);
-              if (sis.getGeneration() == segmentInfos.getGeneration()) {
-                currentCommitPoint = commitPoint;
+              SegmentInfos sis = new SegmentInfos();
+              try {
+                sis.read(directory, fileName, codecs);
+              } catch (FileNotFoundException e) {
+                // LUCENE-948: on NFS (and maybe others), if
+                // you have writers switching back and forth
+                // between machines, it's very likely that the
+                // dir listing will be stale and will claim a
+                // file segments_X exists when in fact it
+                // doesn't.  So, we catch this and handle it
+                // as if the file does not exist
+                if (infoStream != null) {
+                  message("init: hit FileNotFoundException when loading commit \"" + fileName + "\"; skipping this commit point");
+                }
+                sis = null;
               }
-              commits.add(commitPoint);
-              incRef(sis, true);
+              if (sis != null) {
+                CommitPoint commitPoint = new CommitPoint(commitsToDelete, directory, sis);
+                if (sis.getGeneration() == segmentInfos.getGeneration()) {
+                  currentCommitPoint = commitPoint;
+                }
+                commits.add(commitPoint);
+                incRef(sis, true);
+              }
             }
           }
         }
       }
+    } catch (NoSuchDirectoryException e) {
+      // it means the directory is empty, so ignore it.
     }
 
-    if (currentCommitPoint == null) {
+    // If we haven't seen any Lucene files, then currentCommitPoint is expected
+    // to be null, because it means it's a fresh Directory. Therefore it cannot
+    // be any NFS cache issues - so just ignore.
+    if (currentCommitPoint == null && seenIndexFiles) {
       // We did not in fact see the segments_N file
       // corresponding to the segmentInfos that was passed
       // in.  Yet, it must exist, because our caller holds
@@ -235,13 +240,15 @@
 
     // Finally, give policy a chance to remove things on
     // startup:
-    policy.onInit(commits);
+    if (seenIndexFiles) {
+      policy.onInit(commits);
+    }
 
     // Always protect the incoming segmentInfos since
     // sometime it may not be the most recent commit
     checkpoint(segmentInfos, false);
     
-    startingCommitDeleted = currentCommitPoint.isDeleted();
+    startingCommitDeleted = currentCommitPoint == null ? false : currentCommitPoint.isDeleted();
 
     deleteCommits();
   }
Index: lucene/src/java/org/apache/lucene/index/IndexNotFoundException.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/IndexNotFoundException.java	(revision 0)
+++ lucene/src/java/org/apache/lucene/index/IndexNotFoundException.java	(revision 0)
@@ -0,0 +1,32 @@
+package org.apache.lucene.index;
+
+/**
+ * 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;
+
+/**
+ * Signals that no index was found in the Directory. Possibly because the
+ * directory is empty, however can slso indicate an index corruption.
+ */
+public final class IndexNotFoundException extends FileNotFoundException {
+
+  public IndexNotFoundException(String msg) {
+    super(msg);
+  }
+
+}

Property changes on: lucene\src\java\org\apache\lucene\index\IndexNotFoundException.java
___________________________________________________________________
Added: svn:keywords
   + Date Author Id Revision HeadURL
Added: svn:eol-style
   + native

Index: lucene/src/java/org/apache/lucene/index/IndexWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/IndexWriter.java	(revision 932917)
+++ lucene/src/java/org/apache/lucene/index/IndexWriter.java	(working copy)
@@ -1115,25 +1115,16 @@
         // against an index that's currently open for
         // searching.  In this case we write the next
         // segments_N file with no segments:
-        boolean doCommit;
         try {
           segmentInfos.read(directory, codecs);
           segmentInfos.clear();
-          doCommit = false;
         } catch (IOException e) {
           // Likely this means it's a fresh directory
-          doCommit = true;
         }
 
-        if (doCommit) {
-          // Only commit if there is no segments file in
-          // this dir already.
-          segmentInfos.commit(directory);
-        } else {
-          // Record that we have a change (zero out all
-          // segments) pending:
-          changeCount++;
-        }
+        // Record that we have a change (zero out all
+        // segments) pending:
+        changeCount++;
       } else {
         segmentInfos.read(directory, codecs);
 
Index: lucene/src/java/org/apache/lucene/index/SegmentInfos.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentInfos.java	(revision 932917)
+++ lucene/src/java/org/apache/lucene/index/SegmentInfos.java	(working copy)
@@ -649,7 +649,7 @@
           
           if (gen == -1) {
             // Neither approach found a generation
-            throw new FileNotFoundException("no segments* file found in " + directory + ": files: " + Arrays.toString(files));
+            throw new IndexNotFoundException("no segments* file found in " + directory + ": files: " + Arrays.toString(files));
           }
         }
 
Index: lucene/src/java/org/apache/lucene/store/Directory.java
===================================================================
--- lucene/src/java/org/apache/lucene/store/Directory.java	(revision 932879)
+++ lucene/src/java/org/apache/lucene/store/Directory.java	(working copy)
@@ -48,9 +48,12 @@
    * this Directory instance). */
   protected LockFactory lockFactory;
 
-  /** Returns an array of strings, one for each file in the
-   *  directory.
-   * @throws IOException
+  /**
+   * Returns an array of strings, one for each file in the directory.
+   * 
+   * @throws NoSuchDirectoryException if the directory is not prepared for any
+   *         write operations (such as {@link #createOutput(String)})
+   * @throws IOException in case of other IO errors
    */
   public abstract String[] listAll() throws IOException;
 
Index: lucene/src/test/org/apache/lucene/TestSnapshotDeletionPolicy.java
===================================================================
--- lucene/src/test/org/apache/lucene/TestSnapshotDeletionPolicy.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/TestSnapshotDeletionPolicy.java	(working copy)
@@ -45,8 +45,8 @@
 // http://lucenebook.com
 //
 
-public class TestSnapshotDeletionPolicy extends LuceneTestCase
-{
+public class TestSnapshotDeletionPolicy extends LuceneTestCase {
+  
   public static final String INDEX_PATH = "test.snapshots";
 
   public void testSnapshotDeletionPolicy() throws Exception {
@@ -119,7 +119,8 @@
         TEST_VERSION_CURRENT, 
         new StandardAnalyzer(TEST_VERSION_CURRENT)).setIndexDeletionPolicy(dp)
         .setMaxBufferedDocs(2));
-
+    writer.commit();
+    
     final Thread t = new Thread() {
         @Override
         public void run() {
Index: lucene/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java	(working copy)
@@ -558,11 +558,10 @@
       assertTrue("could not locate the 'content' field number in the _2.cfs segment", contentFieldIndex != -1);
 
       // Now verify file names:
-      String[] expected;
-      expected = new String[] {"_0.cfs",
+      String[] expected = new String[] {"_0.cfs",
                                "_0_1.del",
                                "_0_1.s" + contentFieldIndex,
-                               "segments_3",
+                               "segments_2",
                                "segments.gen"};
 
       String[] actual = dir.listAll();
Index: lucene/src/test/org/apache/lucene/index/TestCrash.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestCrash.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestCrash.java	(working copy)
@@ -28,16 +28,19 @@
 
 public class TestCrash extends LuceneTestCase {
 
-  private IndexWriter initIndex() throws IOException {
-    return initIndex(new MockRAMDirectory());
+  private IndexWriter initIndex(boolean initialCommit) throws IOException {
+    return initIndex(new MockRAMDirectory(), initialCommit);
   }
 
-  private IndexWriter initIndex(MockRAMDirectory dir) throws IOException {
+  private IndexWriter initIndex(MockRAMDirectory dir, boolean initialCommit) throws IOException {
     dir.setLockFactory(NoLockFactory.getNoLockFactory());
 
     IndexWriter writer  = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)).setMaxBufferedDocs(10));
     ((ConcurrentMergeScheduler) writer.getConfig().getMergeScheduler()).setSuppressExceptions();
-
+    if (initialCommit) {
+      writer.commit();
+    }
+    
     Document doc = new Document();
     doc.add(new Field("content", "aaa", Field.Store.YES, Field.Index.ANALYZED));
     doc.add(new Field("id", "0", Field.Store.YES, Field.Index.ANALYZED));
@@ -56,7 +59,10 @@
   }
 
   public void testCrashWhileIndexing() throws IOException {
-    IndexWriter writer = initIndex();
+    // This test relies on being able to open a reader before any commit
+    // happened, so we must create an initial commit just to allow that, but
+    // before any documents were added.
+    IndexWriter writer = initIndex(true);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
     crash(writer);
     IndexReader reader = IndexReader.open(dir, false);
@@ -64,11 +70,14 @@
   }
 
   public void testWriterAfterCrash() throws IOException {
-    IndexWriter writer = initIndex();
+    // This test relies on being able to open a reader before any commit
+    // happened, so we must create an initial commit just to allow that, but
+    // before any documents were added.
+    IndexWriter writer = initIndex(true);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
     dir.setPreventDoubleWrite(false);
     crash(writer);
-    writer = initIndex(dir);
+    writer = initIndex(dir, false);
     writer.close();
 
     IndexReader reader = IndexReader.open(dir, false);
@@ -76,10 +85,10 @@
   }
 
   public void testCrashAfterReopen() throws IOException {
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(false);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
     writer.close();
-    writer = initIndex(dir);
+    writer = initIndex(dir, false);
     assertEquals(314, writer.maxDoc());
     crash(writer);
 
@@ -98,7 +107,7 @@
 
   public void testCrashAfterClose() throws IOException {
     
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(false);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
 
     writer.close();
@@ -117,7 +126,7 @@
 
   public void testCrashAfterCloseNoWait() throws IOException {
     
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(false);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
 
     writer.close(false);
@@ -136,7 +145,7 @@
 
   public void testCrashReaderDeletes() throws IOException {
     
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(false);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
 
     writer.close(false);
@@ -157,7 +166,7 @@
 
   public void testCrashReaderDeletesAfterClose() throws IOException {
     
-    IndexWriter writer = initIndex();
+    IndexWriter writer = initIndex(false);
     MockRAMDirectory dir = (MockRAMDirectory) writer.getDirectory();
 
     writer.close(false);
Index: lucene/src/test/org/apache/lucene/index/TestDeletionPolicy.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestDeletionPolicy.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestDeletionPolicy.java	(working copy)
@@ -305,7 +305,7 @@
       writer.optimize();
       writer.close();
 
-      assertEquals(2, policy.numOnInit);
+      assertEquals(1, policy.numOnInit);
 
       // If we are not auto committing then there should
       // be exactly 2 commits (one per close above):
@@ -313,8 +313,8 @@
 
       // Test listCommits
       Collection<IndexCommit> commits = IndexReader.listCommits(dir);
-      // 1 from opening writer + 2 from closing writer
-      assertEquals(3, commits.size());
+      // 2 from closing writer
+      assertEquals(2, commits.size());
 
       // Make sure we can open a reader on each commit:
       for (final IndexCommit commit : commits) {
@@ -374,7 +374,7 @@
     writer.close();
 
     Collection<IndexCommit> commits = IndexReader.listCommits(dir);
-    assertEquals(6, commits.size());
+    assertEquals(5, commits.size());
     IndexCommit lastCommit = null;
     for (final IndexCommit commit : commits) {
       if (lastCommit == null || commit.getGeneration() > lastCommit.getGeneration())
@@ -389,7 +389,7 @@
     writer.optimize();
     writer.close();
 
-    assertEquals(7, IndexReader.listCommits(dir).size());
+    assertEquals(6, IndexReader.listCommits(dir).size());
 
     // Now open writer on the commit just before optimize:
     writer = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT))
@@ -412,7 +412,7 @@
     writer.close();
 
     // Now 8 because we made another commit
-    assertEquals(8, IndexReader.listCommits(dir).size());
+    assertEquals(7, IndexReader.listCommits(dir).size());
     
     r = IndexReader.open(dir, true);
     // Not optimized because we rolled it back, and now only
@@ -491,7 +491,7 @@
       writer.optimize();
       writer.close();
 
-      assertEquals(2, policy.numOnInit);
+      assertEquals(1, policy.numOnInit);
       // If we are not auto committing then there should
       // be exactly 2 commits (one per close above):
       assertEquals(2, policy.numOnCommit);
@@ -537,7 +537,7 @@
       }
 
       assertTrue(policy.numDelete > 0);
-      assertEquals(N+1, policy.numOnInit);
+      assertEquals(N, policy.numOnInit);
       assertEquals(N+1, policy.numOnCommit);
 
       // Simplistic check: just verify only the past N segments_N's still
@@ -625,8 +625,8 @@
       // this is a commit
       writer.close();
 
-      assertEquals(2*(N+2), policy.numOnInit);
-      assertEquals(2*(N+2)-1, policy.numOnCommit);
+      assertEquals(2*(N+1)+1, policy.numOnInit);
+      assertEquals(2*(N+2), policy.numOnCommit);
 
       IndexSearcher searcher = new IndexSearcher(dir, false);
       ScoreDoc[] hits = searcher.search(query, null, 1000).scoreDocs;
@@ -735,8 +735,8 @@
         writer.close();
       }
 
-      assertEquals(1+3*(N+1), policy.numOnInit);
-      assertEquals(3*(N+1), policy.numOnCommit);
+      assertEquals(3*(N+1), policy.numOnInit);
+      assertEquals(3*(N+1)+1, policy.numOnCommit);
 
       IndexSearcher searcher = new IndexSearcher(dir, false);
       ScoreDoc[] hits = searcher.search(query, null, 1000).scoreDocs;
Index: lucene/src/test/org/apache/lucene/index/TestIndexFileDeleter.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexFileDeleter.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestIndexFileDeleter.java	(working copy)
@@ -138,11 +138,11 @@
     copyFile(dir, "_0.cfs", "deletable");
 
     // Create some old segments file:
-    copyFile(dir, "segments_3", "segments");
-    copyFile(dir, "segments_3", "segments_2");
+    copyFile(dir, "segments_2", "segments");
+    copyFile(dir, "segments_2", "segments_1");
 
     // Create a bogus cfs file shadowing a non-cfs segment:
-    copyFile(dir, "_2.cfs", "_3.cfs");
+    copyFile(dir, "_1.cfs", "_2.cfs");
 
     String[] filesPre = dir.listAll();
 
Index: lucene/src/test/org/apache/lucene/index/TestIndexReader.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexReader.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestIndexReader.java	(working copy)
@@ -466,18 +466,17 @@
     public void testLockObtainFailed() throws IOException {
         Directory dir = new RAMDirectory();
 
-        IndexWriter writer = null;
-        IndexReader reader = null;
         Term searchTerm = new Term("content", "aaa");
 
         //  add 11 documents with term : aaa
-        writer  = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)));
+        IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)));
+        writer.commit();
         for (int i = 0; i < 11; i++) {
             addDoc(writer, searchTerm.text());
         }
 
         // Create reader:
-        reader = IndexReader.open(dir, false);
+        IndexReader reader = IndexReader.open(dir, false);
 
         // Try to make changes
         try {
@@ -1749,6 +1748,7 @@
     Directory dir = new MockRAMDirectory();
     IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(
         TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)));
+    writer.commit();
     Document doc = new Document();
     writer.addDocument(doc);
     IndexReader r = IndexReader.open(dir, true);
Index: lucene/src/test/org/apache/lucene/index/TestIndexReaderReopen.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexReaderReopen.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestIndexReaderReopen.java	(working copy)
@@ -174,6 +174,7 @@
     IndexWriter iwriter = new IndexWriter(dir, new IndexWriterConfig(
         TEST_VERSION_CURRENT, new KeywordAnalyzer()).setOpenMode(
         OpenMode.CREATE).setMergeScheduler(new SerialMergeScheduler()));
+    iwriter.commit();
     IndexReader reader = IndexReader.open(dir, false);
     try {
       int M = 3;
Index: lucene/src/test/org/apache/lucene/index/TestIndexWriter.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexWriter.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestIndexWriter.java	(working copy)
@@ -70,6 +70,7 @@
 import org.apache.lucene.store.Lock;
 import org.apache.lucene.store.LockFactory;
 import org.apache.lucene.store.MockRAMDirectory;
+import org.apache.lucene.store.NoLockFactory;
 import org.apache.lucene.store.RAMDirectory;
 import org.apache.lucene.store.SingleInstanceLockFactory;
 import org.apache.lucene.util.UnicodeUtil;
@@ -778,7 +779,7 @@
         writer.close();
 
         long gen = SegmentInfos.getCurrentSegmentGeneration(dir);
-        assertTrue("segment generation should be > 1 but got " + gen, gen > 1);
+        assertTrue("segment generation should be > 0 but got " + gen, gen > 0);
 
         // Make the next segments file, with last byte
         // missing, to simulate a writer that crashed while
@@ -838,7 +839,7 @@
         writer.close();
 
         long gen = SegmentInfos.getCurrentSegmentGeneration(dir);
-        assertTrue("segment generation should be > 1 but got " + gen, gen > 1);
+        assertTrue("segment generation should be > 0 but got " + gen, gen > 0);
 
         String fileNameIn = SegmentInfos.getCurrentSegmentFileName(dir);
         String fileNameOut = IndexFileNames.fileNameFromGeneration(IndexFileNames.SEGMENTS,
@@ -903,7 +904,7 @@
         writer.close();
 
         long gen = SegmentInfos.getCurrentSegmentGeneration(dir);
-        assertTrue("segment generation should be > 1 but got " + gen, gen > 1);
+        assertTrue("segment generation should be > 0 but got " + gen, gen > 0);
 
         String[] files = dir.listAll();
         for(int i=0;i<files.length;i++) {
@@ -2326,7 +2327,7 @@
   public void testImmediateDiskFull() throws IOException {
     MockRAMDirectory dir = new MockRAMDirectory();
     IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)).setMaxBufferedDocs(2));
-    dir.setMaxSizeInBytes(dir.getRecomputedActualSizeInBytes());
+    dir.setMaxSizeInBytes(Math.max(1, dir.getRecomputedActualSizeInBytes()));
     final Document doc = new Document();
     doc.add(new Field("field", "aaa bbb ccc ddd eee fff ggg hhh iii jjj", Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.WITH_POSITIONS_OFFSETS));
     try {
@@ -2644,7 +2645,7 @@
     writer.close();
 
     long gen = SegmentInfos.getCurrentSegmentGeneration(dir);
-    assertTrue("segment generation should be > 1 but got " + gen, gen > 1);
+    assertTrue("segment generation should be > 0 but got " + gen, gen > 0);
 
     final String segmentsFileName = SegmentInfos.getCurrentSegmentFileName(dir);
     IndexInput in = dir.openInput(segmentsFileName);
@@ -2673,7 +2674,8 @@
         TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT))
         .setMaxBufferedDocs(2));
     ((LogMergePolicy) writer.getConfig().getMergePolicy()).setMergeFactor(5);
-
+    writer.commit();
+    
     for (int i = 0; i < 23; i++)
       addDoc(writer);
 
@@ -3534,7 +3536,8 @@
 
     IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)).setMaxBufferedDocs(2));
     ((LogMergePolicy) writer.getConfig().getMergePolicy()).setMergeFactor(5);
-
+    writer.commit();
+    
     for (int i = 0; i < 23; i++)
       addDoc(writer);
 
@@ -3585,7 +3588,8 @@
 
     IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)).setMaxBufferedDocs(2));
     ((LogMergePolicy) writer.getConfig().getMergePolicy()).setMergeFactor(5);
-
+    writer.commit();
+    
     for (int i = 0; i < 23; i++)
       addDoc(writer);
 
@@ -3670,6 +3674,7 @@
 
       dir2 = new MockRAMDirectory();
       writer2 = new IndexWriter(dir2, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)));
+      writer2.commit();
       cms = (ConcurrentMergeScheduler) writer2.getConfig().getMergeScheduler();
 
       readers = new IndexReader[NUM_COPY];
@@ -4952,4 +4957,25 @@
     w.close();
     dir.close();
   }
+  
+  public void testNoCommits() throws Exception {
+    // Tests that if we don't call commit(), the directory has 0 commits. This has
+    // changed since LUCENE-2386, where before IW would always commit on a fresh
+    // new index.
+    Directory dir = new RAMDirectory();
+    IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)));
+    assertEquals("expected 0 commits!", 0, IndexReader.listCommits(dir).size());
+    // No changes still should generate a commit, because it's a new index.
+    writer.close();
+    assertEquals("expected 1 commits!", 1, IndexReader.listCommits(dir).size());
+  }
+
+  public void testEmptyFSDirWithNoLock() throws Exception {
+    // Tests that if FSDir is opened w/ a NoLockFactory (or SingleInstanceLF),
+    // then IndexWriter ctor succeeds. Previously (LUCENE-2386) it failed 
+    // when listAll() was called in IndexFileDeleter.
+    FSDirectory dir = FSDirectory.open(new File(TEMP_DIR, "emptyFSDirNoLock"), NoLockFactory.getNoLockFactory());
+    new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT))).close();
+  }
+  
 }
Index: lucene/src/test/org/apache/lucene/index/TestIndexWriterDelete.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexWriterDelete.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestIndexWriterDelete.java	(working copy)
@@ -749,7 +749,7 @@
 
     MockRAMDirectory dir = new MockRAMDirectory();
     IndexWriter modifier = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)));
-
+    modifier.commit();
     dir.failOn(failure.reset());
 
     for (int i = 0; i < keywords.length; i++) {
Index: lucene/src/test/org/apache/lucene/index/TestIndexWriterExceptions.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexWriterExceptions.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestIndexWriterExceptions.java	(working copy)
@@ -134,6 +134,7 @@
     MockIndexWriter writer  = new MockIndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)).setRAMBufferSizeMB(0.1));
     ((ConcurrentMergeScheduler) writer.getConfig().getMergeScheduler()).setSuppressExceptions();
     //writer.setMaxBufferedDocs(10);
+    writer.commit();
 
     if (VERBOSE)
       writer.setInfoStream(System.out);
@@ -171,6 +172,7 @@
     MockIndexWriter writer  = new MockIndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)).setRAMBufferSizeMB(0.2));
     ((ConcurrentMergeScheduler) writer.getConfig().getMergeScheduler()).setSuppressExceptions();
     //writer.setMaxBufferedDocs(10);
+    writer.commit();
 
     if (VERBOSE)
       writer.setInfoStream(System.out);
Index: lucene/src/test/org/apache/lucene/index/TestIndexWriterReader.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexWriterReader.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestIndexWriterReader.java	(working copy)
@@ -561,6 +561,7 @@
   public void testAfterCommit() throws Exception {
     Directory dir1 = new MockRAMDirectory();
     IndexWriter writer = new IndexWriter(dir1, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)));
+    writer.commit();
     writer.setInfoStream(infoStream);
 
     // create the index
Index: lucene/src/test/org/apache/lucene/index/TestNoDeletionPolicy.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestNoDeletionPolicy.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestNoDeletionPolicy.java	(working copy)
@@ -82,10 +82,7 @@
       doc.add(new Field("c", "a" + i, Store.YES, Index.ANALYZED));
       writer.addDocument(doc);
       writer.commit();
-      // the reason to expect i + 2 commits is because when IndexWriter is
-      // created it creates a first commit. If this ever changes, then the
-      // expected should be i + 1 (and this comment removed).
-      assertEquals("wrong number of commits !", i + 2, IndexReader.listCommits(dir).size());
+      assertEquals("wrong number of commits !", i + 1, IndexReader.listCommits(dir).size());
     }
     writer.close();
   }
Index: lucene/src/test/org/apache/lucene/index/TestStressIndexing.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestStressIndexing.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestStressIndexing.java	(working copy)
@@ -122,7 +122,8 @@
         TEST_VERSION_CURRENT, new SimpleAnalyzer(TEST_VERSION_CURRENT))
         .setOpenMode(OpenMode.CREATE).setMaxBufferedDocs(10).setMergeScheduler(
             mergeScheduler));
-
+    modifier.commit();
+    
     TimedThread[] threads = new TimedThread[4];
     int numThread = 0;
 
Index: lucene/src/test/org/apache/lucene/index/TestStressIndexing2.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestStressIndexing2.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/index/TestStressIndexing2.java	(working copy)
@@ -150,6 +150,7 @@
     IndexWriter w = new MockIndexWriter(dir, new IndexWriterConfig(
         TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)).setOpenMode(OpenMode.CREATE).setRAMBufferSizeMB(
         0.1).setMaxBufferedDocs(maxBufferedDocs));
+    w.commit();
     LogMergePolicy lmp = (LogMergePolicy) w.getConfig().getMergePolicy();
     lmp.setUseCompoundFile(false);
     lmp.setUseCompoundDocStore(false);
Index: lucene/src/test/org/apache/lucene/store/TestLockFactory.java
===================================================================
--- lucene/src/test/org/apache/lucene/store/TestLockFactory.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/store/TestLockFactory.java	(working copy)
@@ -82,7 +82,7 @@
                    NoLockFactory.class.isInstance(dir.getLockFactory()));
 
         IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new WhitespaceAnalyzer(TEST_VERSION_CURRENT)));
-
+        writer.commit(); // required so the second open succeed 
         // Create a 2nd IndexWriter.  This is normally not allowed but it should run through since we're not
         // using any locks:
         IndexWriter writer2 = null;
Index: lucene/src/test/org/apache/lucene/store/TestWindowsMMap.java
===================================================================
--- lucene/src/test/org/apache/lucene/store/TestWindowsMMap.java	(revision 932917)
+++ lucene/src/test/org/apache/lucene/store/TestWindowsMMap.java	(working copy)
@@ -66,17 +66,22 @@
     new File(TEMP_DIR,"testLuceneMmap").getAbsolutePath();
 
   public void testMmapIndex() throws Exception {
-    FSDirectory storeDirectory;
-    storeDirectory = new MMapDirectory(new File(storePathname), null);
-
+    // sometimes the directory is not cleaned by rmDir, because on Windows it
+    // may take some time until the files are finally dereferenced. So clean the
+    // directory up front, or otherwise new IndexWriter will fail.
+    File dirPath = new File(storePathname);
+    rmDir(dirPath);
+    MMapDirectory dir = new MMapDirectory(dirPath, null);
+    
     // plan to add a set of useful stopwords, consider changing some of the
     // interior filters.
     StandardAnalyzer analyzer = new StandardAnalyzer(TEST_VERSION_CURRENT, Collections.emptySet());
     // TODO: something about lock timeouts and leftover locks.
-    IndexWriter writer = new IndexWriter(storeDirectory, new IndexWriterConfig(
+    IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(
         TEST_VERSION_CURRENT, analyzer)
         .setOpenMode(OpenMode.CREATE));
-    IndexSearcher searcher = new IndexSearcher(storeDirectory, true);
+    writer.commit();
+    IndexSearcher searcher = new IndexSearcher(dir, true);
     
     for(int dx = 0; dx < 1000; dx ++) {
       String f = randomField();
@@ -87,14 +92,16 @@
     
     searcher.close();
     writer.close();
-                rmDir(new File(storePathname));
+    rmDir(dirPath);
   }
 
-        private void rmDir(File dir) {
-          File[] files = dir.listFiles();
-          for (int i = 0; i < files.length; i++) {
-            files[i].delete();
-          }
-          dir.delete();
-        }
+  private void rmDir(File dir) {
+    if (!dir.exists()) {
+      return;
+    }
+    for (File file : dir.listFiles()) {
+      file.delete();
+    }
+    dir.delete();
+  }
 }