Index: lucene/contrib/misc/src/test/org/apache/lucene/index/TestIndexSplitter.java
===================================================================
--- lucene/contrib/misc/src/test/org/apache/lucene/index/TestIndexSplitter.java	(revision 1134404)
+++ lucene/contrib/misc/src/test/org/apache/lucene/index/TestIndexSplitter.java	(working copy)
@@ -20,6 +20,7 @@
 
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.document.Document;
+import org.apache.lucene.document.Field;
 import org.apache.lucene.index.IndexWriterConfig.OpenMode;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.util.LuceneTestCase;
@@ -92,4 +93,64 @@
     r.close();
     fsDir.close();
   }
+
+  public void testDeleteThenOptimize() throws Exception {
+    // Create directories where the indexes will reside
+    File indexPath = new File(TEMP_DIR, "testfilesplitter");
+    _TestUtil.rmDir(indexPath);
+    indexPath.mkdirs();
+    File indexSplitPath = new File(TEMP_DIR, "testfilesplitterdest");
+    _TestUtil.rmDir(indexSplitPath);
+    indexSplitPath.mkdirs();
+    
+    // Create the original index
+    LogMergePolicy mergePolicy = new LogByteSizeMergePolicy();
+    mergePolicy.setNoCFSRatio(1);
+    IndexWriterConfig iwConfig
+        = new IndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(random))
+              .setOpenMode(OpenMode.CREATE)
+              .setMergePolicy(mergePolicy);
+    Directory fsDir = newFSDirectory(indexPath);
+    IndexWriter indexWriter = new IndexWriter(fsDir, iwConfig);
+    Document doc = new Document();
+    doc.add(new Field("content", "doc 1", Field.Store.YES, Field.Index.ANALYZED_NO_NORMS));
+    indexWriter.addDocument(doc);
+    doc = new Document();
+    doc.add(new Field("content", "doc 2", Field.Store.YES, Field.Index.ANALYZED_NO_NORMS));
+    indexWriter.addDocument(doc);
+    indexWriter.close();
+    fsDir.close();
+    
+    // Create the split index
+    IndexSplitter indexSplitter = new IndexSplitter(indexPath);
+    String splitSegName = indexSplitter.infos.info(0).name;
+    indexSplitter.split(indexSplitPath, new String[] {splitSegName});
+
+    // Delete the first document in the split index
+    Directory fsDirDest = newFSDirectory(indexSplitPath);
+    IndexReader indexReader = IndexReader.open(fsDirDest, false);
+    indexReader.deleteDocument(0);
+    assertEquals(1, indexReader.numDocs());
+    indexReader.close();
+    fsDirDest.close();
+
+    // Optimize the split index
+    mergePolicy = new LogByteSizeMergePolicy();
+    mergePolicy.setNoCFSRatio(1);
+    iwConfig = new IndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(random))
+                   .setOpenMode(OpenMode.APPEND)
+                   .setMergePolicy(mergePolicy);
+    fsDirDest = newFSDirectory(indexSplitPath);
+    indexWriter = new IndexWriter(fsDirDest, iwConfig);
+    indexWriter.optimize();
+    indexWriter.close();
+    fsDirDest.close();
+
+    // Read the number of docs in the index
+    fsDirDest = newFSDirectory(indexSplitPath);
+    indexReader = IndexReader.open(fsDirDest);
+	  assertEquals(1, indexReader.numDocs());
+    indexReader.close();
+    fsDirDest.close();
+  }
 }
Index: lucene/contrib/misc/src/java/org/apache/lucene/index/IndexSplitter.java
===================================================================
--- lucene/contrib/misc/src/java/org/apache/lucene/index/IndexSplitter.java	(revision 1134404)
+++ lucene/contrib/misc/src/java/org/apache/lucene/index/IndexSplitter.java	(working copy)
@@ -139,6 +139,7 @@
     destDir.mkdirs();
     FSDirectory destFSDir = FSDirectory.open(destDir);
     SegmentInfos destInfos = new SegmentInfos();
+    destInfos.counter = nextSegmentNumber(segs);
     for (String n : segs) {
       SegmentInfo info = getInfo(n);
       destInfos.add(info);
@@ -155,6 +156,17 @@
     // System.out.println("destDir:"+destDir.getAbsolutePath());
   }
 
+  private int nextSegmentNumber(String[] segs) {
+    int nextSegNum = 0;
+    for (String currSeg : segs) {
+      int currSegNum = Integer.parseInt(currSeg.substring(1), 36);
+      if (nextSegNum < currSegNum) {
+        nextSegNum = currSegNum;
+      }
+    }
+    return ++nextSegNum;
+  }
+
   private static final byte[] copyBuffer = new byte[32*1024];
 
   private static void copyFile(File src, File dst) throws IOException {