Index: lucene/core/src/java/org/apache/lucene/index/IndexWriter.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/index/IndexWriter.java	(revision 1528076)
+++ lucene/core/src/java/org/apache/lucene/index/IndexWriter.java	(working copy)
@@ -228,7 +228,7 @@
   final SegmentInfos segmentInfos;       // the segments
   final FieldNumbers globalFieldNumberMap;
 
-  private DocumentsWriter docWriter;
+  private final DocumentsWriter docWriter;
   private final Queue<Event> eventQueue;
   final IndexFileDeleter deleter;
 
@@ -1013,10 +1013,8 @@
         infoStream.message("IW", "at close: " + segString());
       }
       // used by assert below
-      final DocumentsWriter oldWriter = docWriter;
       synchronized(this) {
         readerPool.dropAll(true);
-        docWriter = null;
         deleter.close();
       }
 
@@ -1027,7 +1025,7 @@
       synchronized(this) {
         closed = true;
       }
-      assert oldWriter.perThreadPool.numDeactivatedThreadStates() == oldWriter.perThreadPool.getMaxThreadStates() : "" +  oldWriter.perThreadPool.numDeactivatedThreadStates() + " " +  oldWriter.perThreadPool.getMaxThreadStates();
+      assert docWriter.perThreadPool.numDeactivatedThreadStates() == docWriter.perThreadPool.getMaxThreadStates() : "" +  docWriter.perThreadPool.numDeactivatedThreadStates() + " " +  docWriter.perThreadPool.getMaxThreadStates();
     } catch (OutOfMemoryError oom) {
       handleOOM(oom, "closeInternal");
     } finally {
@@ -1062,14 +1060,7 @@
    *  @see #numDocs */
   public synchronized int maxDoc() {
     ensureOpen();
-    int count;
-    if (docWriter != null)
-      count = docWriter.getNumDocs();
-    else
-      count = 0;
-
-    count += segmentInfos.totalDocCount();
-    return count;
+    return docWriter.getNumDocs() + segmentInfos.totalDocCount();
   }
 
   /** Returns total number of docs in this index, including
@@ -1080,12 +1071,7 @@
    *  @see #numDocs */
   public synchronized int numDocs() {
     ensureOpen();
-    int count;
-    if (docWriter != null)
-      count = docWriter.getNumDocs();
-    else
-      count = 0;
-
+    int count = docWriter.getNumDocs();
     for (final SegmentInfoPerCommit info : segmentInfos) {
       count += info.info.getDocCount() - numDeletedDocs(info);
     }