Index: lucene/core/src/java/org/apache/lucene/search/FieldCacheImpl.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/FieldCacheImpl.java	(revision 1457993)
+++ lucene/core/src/java/org/apache/lucene/search/FieldCacheImpl.java	(working copy)
@@ -1388,7 +1388,7 @@
     }
     
     DocTermOrds dto = (DocTermOrds) caches.get(DocTermOrds.class).get(reader, new CacheKey(field, null), false);
-    return dto.iterator(dto.getOrdTermsEnum(reader));
+    return dto.iterator(reader);
   }
 
   static final class DocTermOrdsCache extends Cache {
Index: lucene/core/src/java/org/apache/lucene/index/DocTermOrds.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/index/DocTermOrds.java	(revision 1457993)
+++ lucene/core/src/java/org/apache/lucene/index/DocTermOrds.java	(working copy)
@@ -24,6 +24,7 @@
 import java.util.List;
 
 import org.apache.lucene.codecs.PostingsFormat; // javadocs
+import org.apache.lucene.index.TermsEnum.SeekStatus;
 import org.apache.lucene.search.DocIdSetIterator;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
@@ -632,7 +633,9 @@
 
     @Override
     public BytesRef next() throws IOException {
-      ord++;
+      if (++ord < 0) {
+        ord = 0;
+      }
       if (termsEnum.next() == null) {
         term = null;
         return null;
@@ -763,16 +766,17 @@
   }
   
   /** Returns a SortedSetDocValues view of this instance */
-  public SortedSetDocValues iterator(TermsEnum termsEnum) throws IOException {
+  public SortedSetDocValues iterator(AtomicReader reader) throws IOException {
     if (isEmpty()) {
       return SortedSetDocValues.EMPTY;
     } else {
-      return new Iterator(termsEnum);
+      return new Iterator(reader);
     }
   }
   
   private class Iterator extends SortedSetDocValues {
-    final TermsEnum te;
+    final AtomicReader reader;
+    final TermsEnum te;  // used internally for lookupOrd() and lookupTerm()
     // currently we read 5 at a time (using the logic of the old iterator)
     final int buffer[] = new int[5];
     int bufferUpto;
@@ -782,8 +786,9 @@
     private int upto;
     private byte[] arr;
     
-    Iterator(TermsEnum te) {
-      this.te = te;
+    Iterator(AtomicReader reader) throws IOException {
+      this.reader = reader;
+      this.te = termsEnum();
     }
     
     @Override
@@ -880,5 +885,27 @@
     public long getValueCount() {
       return numTerms();
     }
+
+    @Override
+    public long lookupTerm(BytesRef key) {
+      try {
+        if (te.seekCeil(key) == SeekStatus.FOUND) {
+          return te.ord();
+        } else {
+          return -te.ord()-1;
+        }
+      } catch (IOException e) {
+        throw new RuntimeException(e);
+      }
+    }
+    
+    @Override
+    public TermsEnum termsEnum() {    
+      try {
+        return getOrdTermsEnum(reader);
+      } catch (IOException e) {
+        throw new RuntimeException();
+      }
+    }
   }
 }
Index: lucene/core/src/test/org/apache/lucene/index/TestDocTermOrds.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/index/TestDocTermOrds.java	(revision 1457993)
+++ lucene/core/src/test/org/apache/lucene/index/TestDocTermOrds.java	(working copy)
@@ -17,18 +17,22 @@
  * limitations under the License.
  */
 
+import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.Set;
 
+import org.apache.lucene.analysis.Analyzer;
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.codecs.Codec;
 import org.apache.lucene.codecs.PostingsFormat;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.IntField;
+import org.apache.lucene.document.StringField;
+import org.apache.lucene.index.TermsEnum.SeekStatus;
 import org.apache.lucene.search.FieldCache;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.util.BytesRef;
@@ -64,7 +68,7 @@
 
     final AtomicReader ar = SlowCompositeReaderWrapper.wrap(r);
     final DocTermOrds dto = new DocTermOrds(ar, ar.getLiveDocs(), "field");
-    SortedSetDocValues iter = dto.iterator(ar.terms("field").iterator(null));
+    SortedSetDocValues iter = dto.iterator(ar);
     
     iter.setDocument(0);
     assertEquals(0, iter.nextOrd());
@@ -352,7 +356,7 @@
       }
     }
 
-    SortedSetDocValues iter = dto.iterator(te);
+    SortedSetDocValues iter = dto.iterator(r);
     for(int docID=0;docID<r.maxDoc();docID++) {
       if (VERBOSE) {
         System.out.println("TEST: docID=" + docID + " of " + r.maxDoc() + " (id=" + docIDToID.get(docID) + ")");
@@ -402,4 +406,76 @@
     r2.close();
     dir.close();
   }
+  
+  public void testSortedTermsEnum() throws IOException {
+    Directory directory = newDirectory();
+    Analyzer analyzer = new MockAnalyzer(random());
+    IndexWriterConfig iwconfig = newIndexWriterConfig(TEST_VERSION_CURRENT, analyzer);
+    iwconfig.setMergePolicy(newLogMergePolicy());
+    RandomIndexWriter iwriter = new RandomIndexWriter(random(), directory, iwconfig);
+    
+    Document doc = new Document();
+    doc.add(new StringField("field", "hello", Field.Store.NO));
+    iwriter.addDocument(doc);
+    
+    doc = new Document();
+    doc.add(new StringField("field", "world", Field.Store.NO));
+    iwriter.addDocument(doc);
+
+    doc = new Document();
+    doc.add(new StringField("field", "beer", Field.Store.NO));
+    iwriter.addDocument(doc);
+    iwriter.forceMerge(1);
+    
+    DirectoryReader ireader = iwriter.getReader();
+    iwriter.close();
+
+    AtomicReader ar = getOnlySegmentReader(ireader);
+    SortedSetDocValues dv = FieldCache.DEFAULT.getDocTermOrds(ar, "field");
+    assertEquals(3, dv.getValueCount());
+    
+    TermsEnum termsEnum = dv.termsEnum();
+    
+    // next()
+    assertEquals("beer", termsEnum.next().utf8ToString());
+    assertEquals(0, termsEnum.ord());
+    assertEquals("hello", termsEnum.next().utf8ToString());
+    assertEquals(1, termsEnum.ord());
+    assertEquals("world", termsEnum.next().utf8ToString());
+    assertEquals(2, termsEnum.ord());
+    
+    // seekCeil()
+    assertEquals(SeekStatus.NOT_FOUND, termsEnum.seekCeil(new BytesRef("ha!")));
+    assertEquals("hello", termsEnum.term().utf8ToString());
+    assertEquals(1, termsEnum.ord());
+    assertEquals(SeekStatus.FOUND, termsEnum.seekCeil(new BytesRef("beer")));
+    assertEquals("beer", termsEnum.term().utf8ToString());
+    assertEquals(0, termsEnum.ord());
+    assertEquals(SeekStatus.END, termsEnum.seekCeil(new BytesRef("zzz")));
+    
+    // seekExact()
+    assertTrue(termsEnum.seekExact(new BytesRef("beer"), true));
+    assertEquals("beer", termsEnum.term().utf8ToString());
+    assertEquals(0, termsEnum.ord());
+    assertTrue(termsEnum.seekExact(new BytesRef("hello"), true));
+    assertEquals("hello", termsEnum.term().utf8ToString());
+    assertEquals(1, termsEnum.ord());
+    assertTrue(termsEnum.seekExact(new BytesRef("world"), true));
+    assertEquals("world", termsEnum.term().utf8ToString());
+    assertEquals(2, termsEnum.ord());
+    assertFalse(termsEnum.seekExact(new BytesRef("bogus"), true));
+    
+    // seek(ord)
+    termsEnum.seekExact(0);
+    assertEquals("beer", termsEnum.term().utf8ToString());
+    assertEquals(0, termsEnum.ord());
+    termsEnum.seekExact(1);
+    assertEquals("hello", termsEnum.term().utf8ToString());
+    assertEquals(1, termsEnum.ord());
+    termsEnum.seekExact(2);
+    assertEquals("world", termsEnum.term().utf8ToString());
+    assertEquals(2, termsEnum.ord());
+    ireader.close();
+    directory.close();
+  }
 }