Index: lucene/src/test/org/apache/lucene/index/TestNewestSegment.java
===================================================================
--- lucene/src/test/org/apache/lucene/index/TestNewestSegment.java	(revision 0)
+++ lucene/src/test/org/apache/lucene/index/TestNewestSegment.java	(revision 0)
@@ -0,0 +1,35 @@
+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 org.apache.lucene.analysis.Analyzer;
+import org.apache.lucene.analysis.SimpleAnalyzer;
+import org.apache.lucene.index.IndexWriter.MaxFieldLength;
+import org.apache.lucene.store.RAMDirectory;
+import org.apache.lucene.util.LuceneTestCase;
+
+public class TestNewestSegment extends LuceneTestCase {
+  public void testNewestSegment() throws Exception {
+    RAMDirectory directory = new RAMDirectory();
+    Analyzer analyzer = new SimpleAnalyzer();
+    IndexWriter writer = new IndexWriter(directory, analyzer,
+        MaxFieldLength.LIMITED);
+    assertNull(writer.newestSegment());
+  }
+  
+}
Index: lucene/src/java/org/apache/lucene/index/IndexWriter.java
===================================================================
--- lucene/src/java/org/apache/lucene/index/IndexWriter.java	(revision 930788)
+++ lucene/src/java/org/apache/lucene/index/IndexWriter.java	(working copy)
@@ -4587,7 +4587,7 @@
 
   // utility routines for tests
   SegmentInfo newestSegment() {
-    return segmentInfos.info(segmentInfos.size()-1);
+    return segmentInfos.size() > 0 ? segmentInfos.info(segmentInfos.size()-1) : null;
   }
 
   public synchronized String segString() {