Index: modules/facet/src/test/org/apache/lucene/facet/taxonomy/TestTaxonomyCombined.java
===================================================================
--- modules/facet/src/test/org/apache/lucene/facet/taxonomy/TestTaxonomyCombined.java	(revision 1201720)
+++ modules/facet/src/test/org/apache/lucene/facet/taxonomy/TestTaxonomyCombined.java	(working copy)
@@ -5,6 +5,7 @@
 import java.io.StringWriter;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Random;
 
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.LockObtainFailedException;
@@ -12,10 +13,12 @@
 import org.junit.Ignore;
 import org.junit.Test;
 
+import org.apache.lucene.util.IOUtils;
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.facet.taxonomy.TaxonomyReader.ChildrenArrays;
 import org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyReader;
 import org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyWriter;
+import org.apache.lucene.index.IndexWriterConfig.OpenMode;
 import org.apache.lucene.util.SlowRAMDirectory;
 
 /**
@@ -847,6 +850,65 @@
     return sw.toString();
   }
   
+  /**
+   * Test that recreating a taxonomy works well with a freshly opened taxonomy reader 
+   */
+  @Test
+  public void testFreshReadRecreatedTaxonomy() throws Exception {
+  	doTestReopenRecreatedTaxonomy(random, true);
+  }
+
+  /**
+   * Test that recreating a taxonomy works well with a reopened taxonomy reader 
+   */
+  @Test
+  public void testReopenReadRecreatedTaxonomy() throws Exception {
+  	doTestReopenRecreatedTaxonomy(random, false);
+  }
+  
+  private void doTestReopenRecreatedTaxonomy(Random random, boolean closeReader) throws Exception {
+  	Directory dir = null;
+  	TaxonomyWriter tw = null;
+  	TaxonomyReader tr = null;
+  	
+	  // prepare a few categories
+  	int  n = 10;
+	  CategoryPath[] cp = new CategoryPath[n];
+	  for (int i=0; i<n; i++) {
+	    cp[i] = new CategoryPath("a", Integer.toString(i));
+    }
+	  
+	  try {
+	  	dir = newDirectory();
+
+	  	tw = new DirectoryTaxonomyWriter(dir);
+	  	tw.addCategory(new CategoryPath("a"));
+	  	tw.close();
+
+	  	tr = new DirectoryTaxonomyReader(dir);
+	  	int baseNumcategories = tr.getSize();
+
+	  	for (int i=0; i<n; i++) {
+	  		int k = random.nextInt(n);
+	  		tw = new DirectoryTaxonomyWriter(dir, OpenMode.CREATE);
+	  		for (int j=0; j<=k; j++) {
+	  			tw.addCategory(new CategoryPath(cp[j]));
+	  		}
+	  		tw.close();
+	  		if (closeReader) {
+	  			tr.close();
+	  			tr = new DirectoryTaxonomyReader(dir);
+	  		} else {
+	  			tr.refresh();
+	  		}
+	  		assertEquals("Wrong #categories in taxonomy (i="+i+", k="+k+")", baseNumcategories + 1 + k, tr.getSize());
+	  	}
+	  } finally {
+	  	IOUtils.close(tr, tw, dir);
+	  }
+  }
+  
+  
   /**  Test that if separate reader and writer objects are opened, new
     categories written into the writer are available to a reader only
     after a commit().