Index: lucene/facet/src/test/org/apache/lucene/facet/taxonomy/TestTaxonomyCombined.java
===================================================================
--- lucene/facet/src/test/org/apache/lucene/facet/taxonomy/TestTaxonomyCombined.java	(revision 1438974)
+++ lucene/facet/src/test/org/apache/lucene/facet/taxonomy/TestTaxonomyCombined.java	(working copy)
@@ -1132,6 +1132,20 @@
     dir.close();
   }
 
+  @Test
+  public void testEmptyString() throws Exception {
+    Directory dir = newDirectory();
+    DirectoryTaxonomyWriter writer = new DirectoryTaxonomyWriter(dir);
+    CategoryPath cp1 = new CategoryPath("test");
+    int ord1 = writer.addCategory(cp1);
+    CategoryPath cp2 = new CategoryPath("test", "");
+    int ord2 = writer.addCategory(cp2);
+    assertTrue(ord1 != ord2);
+    TaxonomyReader reader = new DirectoryTaxonomyReader(writer);
+    assertEquals(cp1, reader.getPath(ord1));
+    assertEquals(cp2, reader.getPath(ord2));
+  }
+
 //  TODO (Facet): test multiple readers, one writer. Have the multiple readers
 //  using the same object (simulating threads) or different objects
 //  (simulating processes).