Index: lucene/src/test/org/apache/lucene/index/TestGlobalFieldNumbers.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestGlobalFieldNumbers.java	(revision 1207504)
+++ lucene/src/test/org/apache/lucene/index/TestGlobalFieldNumbers.java	(working copy)
@@ -75,7 +75,6 @@
         for (String string : files) {
           assertFalse(string.endsWith(".fnx"));
         }
-        assertFNXFiles(dir, "_2.fnx");
         writer.close();
         assertFNXFiles(dir, "_2.fnx");
       }
@@ -127,7 +126,6 @@
         d.add(new BinaryField("f3", new byte[] { 1, 2, 3 }));
         writer.addDocument(d);
         writer.commit();
-        assertFNXFiles(dir, "_2.fnx");
         writer.close();
         assertFNXFiles(dir, "_2.fnx");
       }
Index: lucene/src/test/org/apache/lucene/index/TestIndexWriter.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestIndexWriter.java	(revision 1207504)
+++ lucene/src/test/org/apache/lucene/index/TestIndexWriter.java	(working copy)
@@ -149,8 +149,6 @@
 
     public static void assertNoUnreferencedFiles(Directory dir, String message) throws IOException {
       String[] startFiles = dir.listAll();
-      SegmentInfos infos = new SegmentInfos();
-      infos.read(dir);
       new IndexWriter(dir, new IndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(random))).rollback();
       String[] endFiles = dir.listAll();
 
Index: lucene/src/java/org/apache/lucene/index/SegmentInfos.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/SegmentInfos.java	(revision 1207504)
+++ lucene/src/java/org/apache/lucene/index/SegmentInfos.java	(working copy)
@@ -875,10 +875,10 @@
          */
         files.add(segmentFileName);
       }
-      if (lastGlobalFieldMapVersion > 0) {
-        files.add(getGlobalFieldNumberName(lastGlobalFieldMapVersion));
-      }
     }
+    if (lastGlobalFieldMapVersion > 0) {
+      files.add(getGlobalFieldNumberName(lastGlobalFieldMapVersion));
+    }
     final int size = size();
     for(int i=0;i<size;i++) {
       final SegmentInfo info = info(i);
Index: lucene/src/java/org/apache/lucene/index/IndexWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/IndexWriter.java	(revision 1207504)
+++ lucene/src/java/org/apache/lucene/index/IndexWriter.java	(working copy)
@@ -212,6 +212,8 @@
   volatile SegmentInfos pendingCommit;            // set when a commit is pending (after prepareCommit() & before commit())
   volatile long pendingCommitChangeCount;
 
+  private Collection<String> filesToCommit;
+
   final SegmentInfos segmentInfos;       // the segments
   final FieldNumberBiMap globalFieldNumberMap;
 
@@ -2654,8 +2656,9 @@
             // to commit.  This is important in case, eg, while
             // we are trying to sync all referenced files, a
             // merge completes which would otherwise have
-            // removed the files we are now syncing.
-            deleter.incRef(toCommit, false);
+            // removed the files we are now syncing.    
+            filesToCommit = toCommit.files(directory, false);
+            deleter.incRef(filesToCommit);
           }
           success = true;
         } finally {
@@ -2680,7 +2683,8 @@
     } finally {
       if (!success) {
         synchronized (this) {
-          deleter.decRef(toCommit);
+          deleter.decRef(filesToCommit);
+          filesToCommit = null;
         }
       }
     }
@@ -2780,8 +2784,9 @@
         rollbackSegments = pendingCommit.createBackupSegmentInfos(true);
         deleter.checkpoint(pendingCommit, true);
       } finally {
-        // Matches the incRef done in startCommit:
-        deleter.decRef(pendingCommit);
+        // Matches the incRef done in prepareCommit:
+        deleter.decRef(filesToCommit);
+        filesToCommit = null;
         pendingCommit = null;
         notifyAll();
       }
@@ -3796,7 +3801,8 @@
           if (infoStream != null) {
             infoStream.message("IW", "  skip startCommit(): no changes pending");
           }
-          deleter.decRef(toSync);
+          deleter.decRef(filesToCommit);
+          filesToCommit = null;
           return;
         }
 
@@ -3857,7 +3863,8 @@
             }
 
             // Hit exception
-            deleter.decRef(toSync);
+            deleter.decRef(filesToCommit);
+            filesToCommit = null;
           }
         }
       }