diff --git a/lucene/src/java/org/apache/lucene/index/IndexReader.java b/lucene/src/java/org/apache/lucene/index/IndexReader.java
index 3f8859bf3f1..d1e37c576bd 100644
--- a/lucene/src/java/org/apache/lucene/index/IndexReader.java
+++ b/lucene/src/java/org/apache/lucene/index/IndexReader.java
@@ -996,7 +996,8 @@ public abstract class IndexReader implements Cloneable,Closeable {
   }
 
   /** Returns the byte-encoded normalization factor for the named field of
-   * every document.  This is used by the search code to score documents.
+   *  every document.  This is used by the search code to score documents.
+   *  Returns null if norms were not indexed for this field.
    *
    * @see org.apache.lucene.document.Field#setBoost(float)
    */
diff --git a/lucene/src/java/org/apache/lucene/index/IndexWriter.java b/lucene/src/java/org/apache/lucene/index/IndexWriter.java
index 3b2d7603ccc..2c2ad6181f4 100644
--- a/lucene/src/java/org/apache/lucene/index/IndexWriter.java
+++ b/lucene/src/java/org/apache/lucene/index/IndexWriter.java
@@ -3222,7 +3222,7 @@ public class IndexWriter implements Closeable {
         message("merge segmentCodecs=" + merger.getSegmentCodecs());
         message("merge store matchedCount=" + merger.getMatchedSubReaderCount() + " vs " + merge.readers.size());
       }
-      anyNonBulkMerges |= merger.getMatchedSubReaderCount() != merge.readers.size();
+      anyNonBulkMerges |= merger.getAnyNonBulkMerges();
       
       assert mergedDocCount == totDocCount: "mergedDocCount=" + mergedDocCount + " vs " + totDocCount;
 
diff --git a/lucene/src/java/org/apache/lucene/index/SegmentMerger.java b/lucene/src/java/org/apache/lucene/index/SegmentMerger.java
index a708c93ffcf..279e91e273e 100644
--- a/lucene/src/java/org/apache/lucene/index/SegmentMerger.java
+++ b/lucene/src/java/org/apache/lucene/index/SegmentMerger.java
@@ -571,6 +571,11 @@ final class SegmentMerger {
     return mergeState.delCounts;
   }
   
+  public boolean getAnyNonBulkMerges() {
+    assert matchedCount <= readers.size();
+    return matchedCount != readers.size();
+  }
+
   private void mergeNorms() throws IOException {
     IndexOutput output = null;
     try {
diff --git a/lucene/src/java/org/apache/lucene/index/SegmentReader.java b/lucene/src/java/org/apache/lucene/index/SegmentReader.java
index ac36827bfc6..440e0e23e99 100644
--- a/lucene/src/java/org/apache/lucene/index/SegmentReader.java
+++ b/lucene/src/java/org/apache/lucene/index/SegmentReader.java
@@ -702,7 +702,7 @@ public class SegmentReader extends IndexReader implements Cloneable {
     }
   }
 
-  private void commitChanges(Map<String,String> commitUserData) throws IOException {
+  private synchronized void commitChanges(Map<String,String> commitUserData) throws IOException {
     if (deletedDocsDirty) {               // re-write deleted
       si.advanceDelGen();
 
@@ -923,26 +923,21 @@ public class SegmentReader extends IndexReader implements Cloneable {
     return fieldSet;
   }
 
-
   @Override
-  public synchronized boolean hasNorms(String field) {
+  public boolean hasNorms(String field) {
     ensureOpen();
     return norms.containsKey(field);
   }
 
-  // can return null if norms aren't stored
-  protected synchronized byte[] getNorms(String field) throws IOException {
-    Norm norm = norms.get(field);
-    if (norm == null) return null;  // not indexed, or norms not stored
-    return norm.bytes();
-  }
-
-  // returns fake norms if norms aren't available
   @Override
-  public synchronized byte[] norms(String field) throws IOException {
+  public byte[] norms(String field) throws IOException {
     ensureOpen();
-    byte[] bytes = getNorms(field);
-    return bytes;
+    final Norm norm = norms.get(field);
+    if (norm == null) {
+      // not indexed, or norms not stored
+      return null;  
+    }
+    return norm.bytes();
   }
 
   @Override