Index: src/test/org/apache/lucene/index/TestCodecs.java
===================================================================
--- src/test/org/apache/lucene/index/TestCodecs.java	(revision 919739)
+++ src/test/org/apache/lucene/index/TestCodecs.java	(working copy)
@@ -511,7 +511,9 @@
             DocsAndPositionsEnum postings = termsEnum.docsAndPositions(null, null);
 
             final DocsEnum docsEnum;
-            if (postings != null) {
+            // nocommit -- need way to query codec if it
+            // "supports" positions
+            if (postings != DocsAndPositionsEnum.EMPTY) {
               docsEnum = postings;
             } else {
               docsEnum = docs;
Index: src/test/org/apache/lucene/index/FlexTestUtil.java
===================================================================
--- src/test/org/apache/lucene/index/FlexTestUtil.java	(revision 919739)
+++ src/test/org/apache/lucene/index/FlexTestUtil.java	(working copy)
@@ -73,8 +73,7 @@
   public static void verifyFlexVsPreFlex(Random rand, IndexReader r) throws Exception {
     // First test on DirReader
 
-    // nocommit turn back on
-    // verifyFlexVsPreFlexSingle(rand, r);
+    verifyFlexVsPreFlexSingle(rand, r);
 
     // Then on each individual sub reader
     IndexReader[] subReaders = r.getSequentialSubReaders();
@@ -86,24 +85,18 @@
     }
 
     // Then on a new MultiReader
-    // nocommit -- back on:
-    if (false) {
-      IndexReader m = new MultiReader(subReaders, false);
-      verifyFlexVsPreFlexSingle(rand, m);
-      m.close();
-    }
+    IndexReader m = new MultiReader(subReaders, false);
+    verifyFlexVsPreFlexSingle(rand, m);
+    m.close();
 
     // Then on a forced-external reader (forced flex to
     // emulate API on pre-flex API, which in turn is
     // emulating pre-flex on flex -- twisted, but, better
     // work):
-    // nocommit back on
-    if (false) {
-      verifyFlexVsPreFlexSingle(rand, new ForcedExternalReader(r));
-      IndexReader m = new MultiReader(forcedSubReaders, false);
-      verifyFlexVsPreFlexSingle(rand, m);
-      m.close();
-    }
+    verifyFlexVsPreFlexSingle(rand, new ForcedExternalReader(r));
+    m = new MultiReader(forcedSubReaders, false);
+    verifyFlexVsPreFlexSingle(rand, m);
+    m.close();
   }
 
   private static void verifyFlexVsPreFlexSingle(Random rand, IndexReader r) throws Exception {
@@ -119,7 +112,7 @@
 
     // straight enum of fields/terms/docs/positions
     TermEnum termEnum = r.terms();
-    FieldsEnum fields = r.fields().iterator();
+    FieldsEnum fields = MultiFields.getFields(r).iterator();
     while(true) {
       final String field = fields.next();
       if (field == null) {
@@ -146,8 +139,8 @@
           assertEquals(termEnum.docFreq(), terms.docFreq());
           //allTerms.add(t);
 
-          postings = terms.docsAndPositions(r.getDeletedDocs(), postings);
-          docsEnum = terms.docs(r.getDeletedDocs(), docsEnum);
+          postings = terms.docsAndPositions(MultiFields.getDeletedDocs(r), postings);
+          docsEnum = terms.docs(MultiFields.getDeletedDocs(r), docsEnum);
 
           final DocsEnum docs;
           if (postings != null) {
@@ -166,7 +159,6 @@
               assertTrue(termPos.next());
               assertEquals(termPos.doc(), doc);
               assertEquals(termPos.freq(), docs.freq());
-              //System.out.println("TEST:     doc=" + doc + " freq=" + docs.freq());
               final int freq = docs.freq();
               if (postings == null) {
                 assertEquals(1, freq);
@@ -175,7 +167,6 @@
               } else {
                 for(int i=0;i<freq;i++) {
                   final int position = postings.nextPosition();
-                  //System.out.println("TEST:       pos=" + position);
                   assertEquals(position, termPos.nextPosition());
                   assertEquals(postings.hasPayload(), termPos.isPayloadAvailable());
                   if (postings.hasPayload()) {
@@ -198,7 +189,7 @@
   private static void testRandomSkips(Random rand, IndexReader r) throws Exception {
 
     TermEnum termEnum = r.terms();
-    FieldsEnum fields = r.fields().iterator();
+    FieldsEnum fields = MultiFields.getFields(r).iterator();
     boolean skipNext = false;
     int[] docs1 = new int[16];
     int[] freqs1 = new int[16];
@@ -206,7 +197,6 @@
     int[] freqs2 = new int[16];
     while(true) {
       final String field = fields.next();
-      //System.out.println("TEST: enum field=" + field);
       if (field == null) {
         boolean result = termEnum.next();
         if (result) {
@@ -225,7 +215,6 @@
         DocsAndPositionsEnum postings = null;
         while(true) {
           final BytesRef termRef = terms.next();
-          //System.out.println("TEST:   enum term=" + termRef);
           if (termRef == null) {
             break;
           } else {
@@ -241,9 +230,9 @@
             //allTerms.add(t);
 
             if (rand.nextInt(3) <= 1) {
-              docs = terms.docs(r.getDeletedDocs(), docs);
+              docs = terms.docs(MultiFields.getDeletedDocs(r), docs);
               assert !(docs instanceof DocsAndPositionsEnum): "docs=" + docs;
-              postings = terms.docsAndPositions(r.getDeletedDocs(), postings);
+              postings = terms.docsAndPositions(MultiFields.getDeletedDocs(r), postings);
               final DocsEnum docsEnum;
               if (postings == null) {
                 docsEnum = docs;
@@ -253,17 +242,39 @@
               if (rand.nextBoolean()) {
                 // use bulk read API
                 termDocs.seek(t);
+                int count1 = 0;
+                int count2 = 0;
                 while(true) {
-                  final int count1 = docs.read(docs1, freqs1);
-                  final int count2 = termDocs.read(docs2, freqs2);
-                  assertEquals(count1, count2);
                   if (count1 == 0) {
+                    count1 = docs.read(docs1, freqs1);
+                  }
+                  if (count2 == 0) {
+                    count2 = termDocs.read(docs2, freqs2);
+                  }
+
+                  if (count1 == 0 || count2 == 0) {
+                    assertEquals(0, count2);
+                    assertEquals(0, count1);
                     break;
                   }
-                  for(int i=0;i<count1;i++) {
+                  final int limit = Math.min(count1, count2);
+                  for(int i=0;i<limit;i++) {
                     assertEquals(docs1[i], docs2[i]);
                     assertEquals(freqs1[i], freqs2[i]);
                   }
+                  if (count1 > limit) {
+                    // copy down
+                    System.arraycopy(docs1, limit, docs1, 0, count1-limit);
+                    System.arraycopy(freqs1, limit, freqs1, 0, count1-limit);
+                  }
+                  count1 -= limit;
+
+                  if (count2 > limit) {
+                    // copy down
+                    System.arraycopy(docs2, limit, docs2, 0, count2-limit);
+                    System.arraycopy(freqs2, limit, freqs2, 0, count2-limit);
+                  }
+                  count2 -= limit;
                 }
               } else {
                 // Enum the docs one by one
@@ -387,7 +398,7 @@
   private static void testRandomSeeks(Random rand, IndexReader r) throws Exception {
     final int ITER = 100;
     List<String> allFields = new ArrayList<String>();
-    FieldsEnum fields = r.fields().iterator();
+    FieldsEnum fields = MultiFields.getFields(r).iterator();
     while(true) {
       String f = fields.next();
       if (f == null) {
@@ -409,7 +420,7 @@
       String f = allFields.get(rand.nextInt(fieldCount));
 
       String text = getRandomText(rand, 1, 3, false);
-      final TermsEnum termsEnum = r.fields().terms(f).iterator();
+      final TermsEnum termsEnum = MultiFields.getFields(r).terms(f).iterator();
 
       final TermsEnum.SeekStatus seekStatus = termsEnum.seek(new BytesRef(text));
       Term t = new Term(f, text);
@@ -431,8 +442,8 @@
 
       assertEquals(termsEnum.docFreq(), termEnum.docFreq());
 
-      docs = termsEnum.docs(r.getDeletedDocs(), docs);
-      postings = termsEnum.docsAndPositions(r.getDeletedDocs(), postings);
+      docs = termsEnum.docs(MultiFields.getDeletedDocs(r), docs);
+      postings = termsEnum.docsAndPositions(MultiFields.getDeletedDocs(r), postings);
 
       termPositions.seek(termEnum.term());
 
@@ -489,7 +500,8 @@
 
   // Delegates to a "normal" IndexReader, making it look
   // "external", to force testing of the "flex API on
-  // external reader" layer
+  // external reader" layer.  DO NOT OVERRIDE
+  // getSequentialSubReaders!!
   public final static class ForcedExternalReader extends IndexReader {
     private final IndexReader r;
     public ForcedExternalReader(IndexReader r) {
@@ -513,7 +525,7 @@
     }
 
     public Bits getDeletedDocs() throws IOException {
-      return r.getDeletedDocs();
+      return MultiFields.getDeletedDocs(r);
     }
 
     public int numDocs() {
@@ -540,6 +552,10 @@
       return r.norms(field);
     }
 
+    public String toString() {
+      return "ForcedExternalReader(" + r + ")";
+    }
+
     public void norms(String field, byte[] bytes, int offset) 
       throws IOException {
       r.norms(field, bytes, offset);
Index: src/java/org/apache/lucene/search/MultiTermQueryWrapperFilter.java
===================================================================
--- src/java/org/apache/lucene/search/MultiTermQueryWrapperFilter.java	(revision 919739)
+++ src/java/org/apache/lucene/search/MultiTermQueryWrapperFilter.java	(working copy)
@@ -25,6 +25,7 @@
 import org.apache.lucene.index.TermEnum;
 import org.apache.lucene.index.TermsEnum;
 import org.apache.lucene.index.DocsEnum;
+import org.apache.lucene.index.MultiFields;
 import org.apache.lucene.util.OpenBitSet;
 import org.apache.lucene.util.Bits;
 
@@ -114,7 +115,7 @@
         final int[] docs = new int[32];
         final int[] freqs = new int[32];
         int termCount = 0;
-        final Bits delDocs = reader.getDeletedDocs();
+        final Bits delDocs = MultiFields.getDeletedDocs(reader);
         DocsEnum docsEnum = null;
         do {
           termCount++;
Index: src/java/org/apache/lucene/search/MatchAllDocsQuery.java
===================================================================
--- src/java/org/apache/lucene/search/MatchAllDocsQuery.java	(revision 919739)
+++ src/java/org/apache/lucene/search/MatchAllDocsQuery.java	(working copy)
@@ -19,6 +19,7 @@
 
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.Term;
+import org.apache.lucene.index.MultiFields;
 import org.apache.lucene.util.ToStringUtils;
 import org.apache.lucene.util.Bits;
 
@@ -54,7 +55,7 @@
     MatchAllScorer(IndexReader reader, Similarity similarity, Weight w,
         byte[] norms) throws IOException {
       super(similarity);
-      delDocs = reader.getDeletedDocs();
+      delDocs = MultiFields.getDeletedDocs(reader);
       score = w.getValue();
       maxDoc = reader.maxDoc();
       this.norms = norms;
Index: src/java/org/apache/lucene/search/FieldCacheRangeFilter.java
===================================================================
--- src/java/org/apache/lucene/search/FieldCacheRangeFilter.java	(revision 919739)
+++ src/java/org/apache/lucene/search/FieldCacheRangeFilter.java	(working copy)
@@ -19,6 +19,7 @@
 import java.io.IOException;
 
 import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.MultiFields;
 import org.apache.lucene.util.NumericUtils;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.document.NumericField; // for javadocs
@@ -537,7 +538,7 @@
         if (isCacheable()) {
           skipDocs = null;
         } else {
-          skipDocs = reader.getDeletedDocs();
+          skipDocs = MultiFields.getDeletedDocs(reader);
         }
       }
       final int maxDoc = reader.maxDoc();
Index: src/java/org/apache/lucene/search/FilteredTermsEnum.java
===================================================================
--- src/java/org/apache/lucene/search/FilteredTermsEnum.java	(revision 919739)
+++ src/java/org/apache/lucene/search/FilteredTermsEnum.java	(working copy)
@@ -19,7 +19,6 @@
 
 import java.io.IOException;
 import org.apache.lucene.index.IndexReader;
-import org.apache.lucene.index.Terms;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.index.TermsEnum;
 import org.apache.lucene.index.MultiFields;
@@ -63,12 +62,7 @@
    * Creates a filtered {@link TermsEnum} for the given field name and reader.
    */
   public FilteredTermsEnum(final IndexReader reader, final String field) throws IOException {
-    final Terms terms = MultiFields.getTerms(reader, field);
-    if (terms != null) {
-      tenum = terms.iterator();
-    } else {
-      tenum = null;
-    }
+    tenum = MultiFields.getTerms(reader, field).iterator();
   }
 
   /**
@@ -122,22 +116,22 @@
     /* if we have no tenum, we return a new attributes instance,
      * to prevent NPE in subclasses that use attributes.
      * in all other cases we share the attributes with our delegate. */
-    return (tenum == null) ? super.attributes() : tenum.attributes();
+    return tenum.attributes();
   }
   
   @Override
   public BytesRef term() throws IOException {
-    return (tenum == null) ? null : tenum.term();
+    return tenum.term();
   }
 
   @Override
   public BytesRef.Comparator getComparator() throws IOException {
-    return (tenum == null) ? null : tenum.getComparator();
+    return tenum.getComparator();
   }
     
   @Override
   public int docFreq() {
-    return (tenum == null) ? -1 : tenum.docFreq();
+    return tenum.docFreq();
   }
 
   /** This enum does not support seeking!
@@ -158,23 +152,21 @@
 
   @Override
   public long ord() throws IOException {
-    return (tenum == null) ? -1 : tenum.ord();
+    return tenum.ord();
   }
 
   @Override
   public DocsEnum docs(Bits bits, DocsEnum reuse) throws IOException {
-    return (tenum == null) ? null : tenum.docs(bits, reuse);
+    return tenum.docs(bits, reuse);
   }
     
   @Override
   public DocsAndPositionsEnum docsAndPositions(Bits bits, DocsAndPositionsEnum reuse) throws IOException {
-    return (tenum == null) ? null : tenum.docsAndPositions(bits, reuse);
+    return tenum.docsAndPositions(bits, reuse);
   }
     
   @Override
   public BytesRef next() throws IOException {
-    if (tenum == null)
-      return null;
     for (;;) {
       // Seek or forward the iterator
       if (doSeek) {
Index: src/java/org/apache/lucene/search/spans/SpanTermQuery.java
===================================================================
--- src/java/org/apache/lucene/search/spans/SpanTermQuery.java	(revision 919739)
+++ src/java/org/apache/lucene/search/spans/SpanTermQuery.java	(working copy)
@@ -86,7 +86,7 @@
     // NOTE: debateably, the caller should never pass in a
     // multi reader...
     final DocsAndPositionsEnum postings = MultiFields.getTermPositionsEnum(reader,
-                                                                           reader.getDeletedDocs(),
+                                                                           MultiFields.getDeletedDocs(reader),
                                                                            term.field(),
                                                                            new BytesRef(term.text()));
 
Index: src/java/org/apache/lucene/search/MultiPhraseQuery.java
===================================================================
--- src/java/org/apache/lucene/search/MultiPhraseQuery.java	(revision 919739)
+++ src/java/org/apache/lucene/search/MultiPhraseQuery.java	(working copy)
@@ -23,6 +23,7 @@
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.index.DocsEnum;
+import org.apache.lucene.index.MultiFields;
 import org.apache.lucene.index.DocsAndPositionsEnum;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.ToStringUtils;
@@ -178,7 +179,7 @@
         if (terms.length > 1) {
           postingsEnum = new UnionDocsAndPositionsEnum(reader, terms);
         } else {
-          postingsEnum = reader.termPositionsEnum(reader.getDeletedDocs(),
+          postingsEnum = reader.termPositionsEnum(MultiFields.getDeletedDocs(reader),
                                                   terms[0].field(),
                                                   new BytesRef(terms[0].text()));
         }
@@ -454,7 +455,7 @@
 
   public UnionDocsAndPositionsEnum(IndexReader indexReader, Term[] terms) throws IOException {
     List<DocsAndPositionsEnum> docsEnums = new LinkedList<DocsAndPositionsEnum>();
-    final Bits delDocs = indexReader.getDeletedDocs();
+    final Bits delDocs = MultiFields.getDeletedDocs(indexReader);
     for (int i = 0; i < terms.length; i++) {
       DocsAndPositionsEnum postings = indexReader.termPositionsEnum(delDocs,
                                                                     terms[i].field(),
Index: src/java/org/apache/lucene/search/PrefixQuery.java
===================================================================
--- src/java/org/apache/lucene/search/PrefixQuery.java	(revision 919739)
+++ src/java/org/apache/lucene/search/PrefixQuery.java	(working copy)
@@ -20,7 +20,6 @@
 import java.io.IOException;
 
 import org.apache.lucene.index.IndexReader;
-import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.index.MultiFields;
@@ -52,8 +51,7 @@
   @Override  
   protected TermsEnum getTermsEnum(IndexReader reader) throws IOException {
     if (prefix.text().length() == 0) {
-      final Terms terms = MultiFields.getTerms(reader, getField());
-      return (terms != null) ? terms.iterator() : TermsEnum.EMPTY;
+      return MultiFields.getTerms(reader, getField()).iterator();
     }
     return new PrefixTermsEnum(reader, prefix);
   }
Index: src/java/org/apache/lucene/search/function/ValueSourceQuery.java
===================================================================
--- src/java/org/apache/lucene/search/function/ValueSourceQuery.java	(revision 919739)
+++ src/java/org/apache/lucene/search/function/ValueSourceQuery.java	(working copy)
@@ -20,6 +20,7 @@
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.search.*;
 import org.apache.lucene.index.Term;
+import org.apache.lucene.index.MultiFields;
 import org.apache.lucene.util.ToStringUtils;
 import org.apache.lucene.util.Bits;
 
@@ -137,7 +138,7 @@
       qWeight = w.getValue();
       // this is when/where the values are first created.
       vals = valSrc.getValues(reader);
-      delDocs = reader.getDeletedDocs();
+      delDocs = MultiFields.getDeletedDocs(reader);
       maxDoc = reader.maxDoc();
     }
 
Index: src/java/org/apache/lucene/search/PhraseQuery.java
===================================================================
--- src/java/org/apache/lucene/search/PhraseQuery.java	(revision 919739)
+++ src/java/org/apache/lucene/search/PhraseQuery.java	(working copy)
@@ -24,6 +24,7 @@
 import org.apache.lucene.index.Term;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.index.DocsAndPositionsEnum;
+import org.apache.lucene.index.DocsEnum;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.MultiFields;
 import org.apache.lucene.search.Explanation.IDFExplanation;
@@ -154,7 +155,7 @@
         return null;
 
       DocsAndPositionsEnum[] postings = new DocsAndPositionsEnum[terms.size()];
-      final Bits delDocs = reader.getDeletedDocs();
+      final Bits delDocs = MultiFields.getDeletedDocs(reader);
       for (int i = 0; i < terms.size(); i++) {
         final Term t = terms.get(i);
         final BytesRef text = new BytesRef(t.text());
@@ -164,11 +165,18 @@
                                                                              delDocs,
                                                                              t.field(),
                                                                              text);
-        if (postingsEnum == null) {
+        assert postingsEnum != null: "reader=" + reader;
+
+        // nocommit -- need a way to directly ask if codec
+        // stores positions
+        // try to notify user when they are running
+        // PhraseQuery on a field that did not index
+        // positions.
+        if (postingsEnum == DocsAndPositionsEnum.EMPTY) {
           if (MultiFields.getTermDocsEnum(reader,
                                           delDocs,
                                           t.field(),
-                                          text) != null) {
+                                          text) != DocsEnum.EMPTY) {
             // term does exist, but has no positions
             throw new IllegalStateException("field \"" + t.field() + "\" was indexed with Field.omitTermFreqAndPositions=true; cannot run PhraseQuery (term=" + t.text() + ")");
           } else {
Index: src/java/org/apache/lucene/search/TermRangeQuery.java
===================================================================
--- src/java/org/apache/lucene/search/TermRangeQuery.java	(revision 919739)
+++ src/java/org/apache/lucene/search/TermRangeQuery.java	(working copy)
@@ -22,7 +22,6 @@
 
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.TermsEnum;
-import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.MultiFields;
 import org.apache.lucene.util.ToStringUtils;
 
@@ -143,8 +142,7 @@
     if ((lowerTerm == null || (collator == null && includeLower && "".equals(lowerTerm))) && upperTerm == null) {
       // NOTE: debateably, the caller should never pass in a
       // multi reader...
-      final Terms terms = MultiFields.getTerms(reader, field);
-      return (terms != null) ? terms.iterator() : TermsEnum.EMPTY;
+      return MultiFields.getTerms(reader, field).iterator();
     }
     return new TermRangeTermsEnum(reader, field,
         lowerTerm, upperTerm, includeLower, includeUpper, collator);
Index: src/java/org/apache/lucene/search/TermQuery.java
===================================================================
--- src/java/org/apache/lucene/search/TermQuery.java	(revision 919739)
+++ src/java/org/apache/lucene/search/TermQuery.java	(working copy)
@@ -75,7 +75,7 @@
     public Scorer scorer(IndexReader reader, boolean scoreDocsInOrder, boolean topScorer) throws IOException {
       // NOTE: debateably, the caller should never pass in a
       // multi reader...
-      DocsEnum docs = MultiFields.getTermDocsEnum(reader, reader.getDeletedDocs(), term.field(), new BytesRef(term.text()));
+      DocsEnum docs = MultiFields.getTermDocsEnum(reader, MultiFields.getDeletedDocs(reader), term.field(), new BytesRef(term.text()));
       if (docs == null) {
         return null;
       }
@@ -118,7 +118,7 @@
 
       Explanation tfExplanation = new Explanation();
       int tf = 0;
-      DocsEnum docs = reader.termDocsEnum(reader.getDeletedDocs(), term.field(), new BytesRef(term.text()));
+      DocsEnum docs = reader.termDocsEnum(MultiFields.getDeletedDocs(reader), term.field(), new BytesRef(term.text()));
       if (docs != null) {
           int newDoc = docs.advance(doc);
           if (newDoc == doc) {
Index: src/java/org/apache/lucene/search/FieldCacheImpl.java
===================================================================
--- src/java/org/apache/lucene/search/FieldCacheImpl.java	(revision 919739)
+++ src/java/org/apache/lucene/search/FieldCacheImpl.java	(working copy)
@@ -283,7 +283,7 @@
       Terms terms = MultiFields.getTerms(reader, field);
       if (terms != null) {
         final TermsEnum termsEnum = terms.iterator();
-        final Bits delDocs = reader.getDeletedDocs();
+        final Bits delDocs = MultiFields.getDeletedDocs(reader);
         DocsEnum docs = null;
         try {
           while(true) {
@@ -337,7 +337,7 @@
       Terms terms = MultiFields.getTerms(reader, field);
       if (terms != null) {
         final TermsEnum termsEnum = terms.iterator();
-        final Bits delDocs = reader.getDeletedDocs();
+        final Bits delDocs = MultiFields.getDeletedDocs(reader);
         DocsEnum docs = null;
         try {
           while(true) {
@@ -396,7 +396,7 @@
       Terms terms = MultiFields.getTerms(reader, field);
       if (terms != null) {
         final TermsEnum termsEnum = terms.iterator();
-        final Bits delDocs = reader.getDeletedDocs();
+        final Bits delDocs = MultiFields.getDeletedDocs(reader);
         DocsEnum docs = null;
         try {
           while(true) {
@@ -468,7 +468,7 @@
       Terms terms = MultiFields.getTerms(reader, field);
       if (terms != null) {
         final TermsEnum termsEnum = terms.iterator();
-        final Bits delDocs = reader.getDeletedDocs();
+        final Bits delDocs = MultiFields.getDeletedDocs(reader);
         DocsEnum docs = null;
         try {
           while(true) {
@@ -536,7 +536,7 @@
       Terms terms = MultiFields.getTerms(reader, field);
       if (terms != null) {
         final TermsEnum termsEnum = terms.iterator();
-        final Bits delDocs = reader.getDeletedDocs();
+        final Bits delDocs = MultiFields.getDeletedDocs(reader);
         DocsEnum docs = null;
         try {
           while(true) {
@@ -606,7 +606,7 @@
       Terms terms = MultiFields.getTerms(reader, field);
       if (terms != null) {
         final TermsEnum termsEnum = terms.iterator();
-        final Bits delDocs = reader.getDeletedDocs();
+        final Bits delDocs = MultiFields.getDeletedDocs(reader);
         DocsEnum docs = null;
         try {
           while(true) {
@@ -658,7 +658,7 @@
       Terms terms = MultiFields.getTerms(reader, field);
       if (terms != null) {
         final TermsEnum termsEnum = terms.iterator();
-        final Bits delDocs = reader.getDeletedDocs();
+        final Bits delDocs = MultiFields.getDeletedDocs(reader);
         DocsEnum docs = null;
         while(true) {
           final BytesRef term = termsEnum.next();
@@ -711,7 +711,7 @@
 
       if (terms != null) {
         final TermsEnum termsEnum = terms.iterator();
-        final Bits delDocs = reader.getDeletedDocs();
+        final Bits delDocs = MultiFields.getDeletedDocs(reader);
         DocsEnum docs = null;
         while(true) {
           final BytesRef term = termsEnum.next();
Index: src/java/org/apache/lucene/search/AutomatonQuery.java
===================================================================
--- src/java/org/apache/lucene/search/AutomatonQuery.java	(revision 919739)
+++ src/java/org/apache/lucene/search/AutomatonQuery.java	(working copy)
@@ -21,7 +21,6 @@
 
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.Term;
-import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.TermsEnum;
 import org.apache.lucene.index.MultiFields;
 import org.apache.lucene.util.ToStringUtils;
@@ -79,9 +78,7 @@
     
     // matches all possible strings
     if (BasicOperations.isTotal(automaton)) {
-      final Terms terms = MultiFields.getTerms(reader, getField());
-      // nocommit -- should we just return null?  singleton?
-      return (terms != null) ? terms.iterator() : TermsEnum.EMPTY;
+      return MultiFields.getTerms(reader, getField()).iterator();
     }
     
     // matches a fixed string in singleton representation
Index: src/java/org/apache/lucene/index/LegacyFieldsEnum.java
===================================================================
--- src/java/org/apache/lucene/index/LegacyFieldsEnum.java	(revision 919739)
+++ src/java/org/apache/lucene/index/LegacyFieldsEnum.java	(working copy)
@@ -197,11 +197,11 @@
       this.term = term;
       td.seek(term);
 
-      if (skipDocs != r.getDeletedDocs()) {
+      if (skipDocs != MultiFields.getDeletedDocs(r)) {
         // An external reader's TermDocs/Positions will
         // silently skip deleted docs, so, we can't allow
         // arbitrary skipDocs here:
-        throw new IllegalStateException("external IndexReader requires skipDocs == IndexReader.getDeletedDocs()");
+        throw new IllegalStateException("external IndexReader requires skipDocs == MultiFields.getDeletedDocs()");
       }
 
       return this;
@@ -256,11 +256,11 @@
       this.term = term;
       tp.seek(term);
 
-      if (skipDocs != r.getDeletedDocs()) {
+      if (skipDocs != MultiFields.getDeletedDocs(r)) {
         // An external reader's TermDocs/Positions will
         // silently skip deleted docs, so, we can't allow
         // arbitrary skipDocs here:
-        throw new IllegalStateException("external IndexReader requires skipDocs == IndexReader.getDeletedDocs()");
+        throw new IllegalStateException("external IndexReader requires skipDocs == MultiFields.getDeletedDocs() skipDocs=" + skipDocs + " MultiFields.getDeletedDocs=" + MultiFields.getDeletedDocs(r) + " r=" + r);
       }
 
       return this;
Index: src/java/org/apache/lucene/index/FieldsEnum.java
===================================================================
--- src/java/org/apache/lucene/index/FieldsEnum.java	(revision 919739)
+++ src/java/org/apache/lucene/index/FieldsEnum.java	(working copy)
@@ -28,7 +28,8 @@
 
 public abstract class FieldsEnum {
 
-  public final static FieldsEnum[] EMPTY_ARRAY = new FieldsEnum[0];
+  // TODO: maybe allow retrieving FieldInfo for current
+  // field, as optional method?
 
   private AttributeSource atts = null;
 
@@ -36,25 +37,38 @@
    * Returns the related attributes.
    */
   public AttributeSource attributes() {
-    if (atts == null) atts = new AttributeSource();
+    if (atts == null) {
+      atts = new AttributeSource();
+    }
     return atts;
   }
   
-  // nocommit -- do we need seek?
-  // nocommit -- should this return FieldInfo?
   /** Increments the enumeration to the next field.  The
    *  returned field is always interned, so simple ==
    *  comparison is allowed.  Returns null when there are no
    *  more fields.*/
   public abstract String next() throws IOException;
 
-  // nocommit should we add a field()?  fieldInfo()?
-  // mirrors TermsEnum
-
   /** Get {@link TermsEnum} for the current field.  You
-   *  should not call {@link #next()} until you're done
-   *  using this {@link TermsEnum}.  After {@link #next}
-   *  returns null, this method should not be called. */
+   *  should not call {@link #next} until you're done using
+   *  this {@link TermsEnum}.  After {@link #next} returns
+   *  null, this method should not be called. This method
+   *  will not return null. */
   public abstract TermsEnum terms() throws IOException;
+
+  public final static FieldsEnum[] EMPTY_ARRAY = new FieldsEnum[0];
+
+  /** Provides zero fields */
+  public final static FieldsEnum EMPTY = new FieldsEnum() {
+
+    @Override
+    public String next() {
+      return null;
+    }
+
+    @Override
+    public TermsEnum terms() {
+      throw new IllegalStateException("this method should never be called");
+    }
+  };
 }
-
Index: src/java/org/apache/lucene/index/MultiTerms.java
===================================================================
--- src/java/org/apache/lucene/index/MultiTerms.java	(revision 919739)
+++ src/java/org/apache/lucene/index/MultiTerms.java	(working copy)
@@ -1,6 +1,5 @@
 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
@@ -72,7 +71,7 @@
     if (termsEnums.size() > 0) {
       return new MultiTermsEnum(subSlices).reset(termsEnums.toArray(MultiTermsEnum.TermsEnumIndex.EMPTY_ARRAY));
     } else {
-      return null;
+      return TermsEnum.EMPTY;
     }
   }
 
Index: src/java/org/apache/lucene/index/SegmentInfo.java
===================================================================
--- src/java/org/apache/lucene/index/SegmentInfo.java	(revision 919739)
+++ src/java/org/apache/lucene/index/SegmentInfo.java	(working copy)
@@ -90,13 +90,12 @@
 
   private boolean hasProx;                        // True if this segment has any fields with omitTermFreqAndPositions==false
   
-  // nocommit: unread field
-  private boolean flexPostings;                   // True if postings were written with new flex format
   private Codec codec;
 
 
   private Map<String,String> diagnostics;
 
+   // nocommit -- who uses this one?
   public SegmentInfo(String name, int docCount, Directory dir, Codec codec) {
     this.name = name;
     this.docCount = docCount;
@@ -110,17 +109,9 @@
     docStoreIsCompoundFile = false;
     delCount = 0;
     hasProx = true;
-    flexPostings = true;
     this.codec = codec;
   }
 
-  // nocommit -- this ctor is only used by back-compat tests
-  public SegmentInfo(String name, int docCount, Directory dir, boolean isCompoundFile, boolean hasSingleNormFile) { 
-    this(name, docCount, dir, isCompoundFile, hasSingleNormFile, -1, null, false, true, null);
-    SegmentWriteState state = new SegmentWriteState(null, dir, name, null, null, docCount, docCount, -1, Codecs.getDefault());
-    codec = state.codec = Codecs.getDefault().getWriter(state);
-  }
-  
   public SegmentInfo(String name, int docCount, Directory dir, boolean isCompoundFile, boolean hasSingleNormFile, 
                      int docStoreOffset, String docStoreSegment, boolean docStoreIsCompoundFile, boolean hasProx,
                      Codec codec) { 
@@ -627,11 +618,9 @@
     if (useCompoundFile) {
       files.add(IndexFileNames.segmentFileName(name, IndexFileNames.COMPOUND_FILE_EXTENSION));
     } else {
-      final String[] exts = IndexFileNames.NON_STORE_INDEX_EXTENSIONS;
       for(String ext : IndexFileNames.NON_STORE_INDEX_EXTENSIONS) {
         addIfExists(files, IndexFileNames.segmentFileName(name, ext));
       }
-      // nocommit -- only does ifExists on prx for standard codec
       codec.files(dir, this, files);
     }
 
Index: src/java/org/apache/lucene/index/ParallelReader.java
===================================================================
--- src/java/org/apache/lucene/index/ParallelReader.java	(revision 919739)
+++ src/java/org/apache/lucene/index/ParallelReader.java	(working copy)
@@ -171,7 +171,7 @@
       if (terms != null) {
         return terms.iterator();
       } else {
-        return null;
+        return TermsEnum.EMPTY;
       }
     }
   }
@@ -196,7 +196,7 @@
 
   @Override
   public Bits getDeletedDocs() throws IOException {
-    return ((IndexReader) readers.get(0)).getDeletedDocs();
+    return MultiFields.getDeletedDocs(readers.get(0));
   }
 
   @Override
Index: src/java/org/apache/lucene/index/SegmentReader.java
===================================================================
--- src/java/org/apache/lucene/index/SegmentReader.java	(revision 919739)
+++ src/java/org/apache/lucene/index/SegmentReader.java	(working copy)
@@ -57,7 +57,6 @@
 
   private SegmentInfo si;
   private int readBufferSize;
-  boolean isPreFlex;
 
   CloseableThreadLocal<FieldsReader> fieldsReaderLocal = new FieldsReaderLocal();
   CloseableThreadLocal<TermVectorsReader> termVectorsLocal = new CloseableThreadLocal<TermVectorsReader>();
@@ -835,7 +834,7 @@
   @Override
   public TermEnum terms() throws IOException {
     ensureOpen();
-    if (isPreFlex) {
+    if (core.isPreFlex) {
       // For old API on an old segment, instead of
       // converting old API -> new API -> old API, just give
       // direct access to old:
@@ -852,7 +851,7 @@
   @Override
   public TermEnum terms(Term t) throws IOException {
     ensureOpen();
-    if (isPreFlex) {
+    if (core.isPreFlex) {
       // For old API on an old segment, instead of
       // converting old API -> new API -> old API, just give
       // direct access to old:
@@ -901,7 +900,7 @@
   @Override
   public TermDocs termDocs() throws IOException {
     ensureOpen();
-    if (isPreFlex) {
+    if (core.isPreFlex) {
       // For old API on an old segment, instead of
       // converting old API -> new API -> old API, just give
       // direct access to old:
@@ -921,7 +920,7 @@
   @Override
   public TermPositions termPositions() throws IOException {
     ensureOpen();
-    if (isPreFlex) {
+    if (core.isPreFlex) {
       // For old API on an old segment, instead of
       // converting old API -> new API -> old API, just give
       // direct access to old:
Index: src/java/org/apache/lucene/index/SegmentInfos.java
===================================================================
--- src/java/org/apache/lucene/index/SegmentInfos.java	(revision 919739)
+++ src/java/org/apache/lucene/index/SegmentInfos.java	(working copy)
@@ -384,9 +384,9 @@
   public Object clone() {
     SegmentInfos sis = (SegmentInfos) super.clone();
     for(int i=0;i<sis.size();i++) {
-      // nocommit
-      assert sis.info(i).getCodec() != null;
-      sis.set(i, (SegmentInfo) sis.info(i).clone());
+      final SegmentInfo info = sis.info(i);
+      assert info.getCodec() != null;
+      sis.set(i, (SegmentInfo) info.clone());
     }
     sis.userData = new HashMap<String,String>(userData);
     return sis;
Index: src/java/org/apache/lucene/index/CheckIndex.java
===================================================================
--- src/java/org/apache/lucene/index/CheckIndex.java	(revision 919739)
+++ src/java/org/apache/lucene/index/CheckIndex.java	(working copy)
@@ -492,7 +492,7 @@
         segInfoStat.fieldNormStatus = testFieldNorms(fieldNames, reader);
 
         // Test the Term Index
-        segInfoStat.termIndexStatus = testTermIndex(info, reader);
+        segInfoStat.termIndexStatus = testTermIndex(reader);
 
         // Test Stored Fields
         segInfoStat.storedFieldStatus = testStoredFields(info, reader, nf);
@@ -575,7 +575,7 @@
   /**
    * Test the term index.
    */
-  private Status.TermIndexStatus testTermIndex(SegmentInfo info, SegmentReader reader) {
+  private Status.TermIndexStatus testTermIndex(SegmentReader reader) {
     final Status.TermIndexStatus status = new Status.TermIndexStatus();
 
     final int maxDoc = reader.maxDoc();
@@ -612,7 +612,9 @@
           postings = terms.docsAndPositions(delDocs, postings);
 
           final DocsEnum docs2;
-          if (postings != null) {
+          // nocommit -- need a way to ask codec if it
+          // supports positions
+          if (postings != DocsAndPositionsEnum.EMPTY) {
             docs2 = postings;
           } else {
             docs2 = docs;
@@ -642,7 +644,9 @@
             }
             
             int lastPos = -1;
-            if (postings != null) {
+            // nocommit -- need a way to ask codec if it
+            // supports positions
+            if (postings != DocsAndPositionsEnum.EMPTY) {
               for(int j=0;j<freq;j++) {
                 final int pos = postings.nextPosition();
                 if (pos < -1) {
Index: src/java/org/apache/lucene/index/Terms.java
===================================================================
--- src/java/org/apache/lucene/index/Terms.java	(revision 919739)
+++ src/java/org/apache/lucene/index/Terms.java	(working copy)
@@ -29,20 +29,18 @@
 
 public abstract class Terms {
 
-  public final static Terms[] EMPTY_ARRAY = new Terms[0];
-
   // Privately cache a TermsEnum per-thread for looking up
   // docFreq and getting a private DocsEnum
   private final CloseableThreadLocal<TermsEnum> threadEnums = new CloseableThreadLocal<TermsEnum>();
 
-  /** Returns an iterator that will step through all terms */
+  /** Returns an iterator that will step through all
+   * terms. This method will not return null.*/
   public abstract TermsEnum iterator() throws IOException;
   
   /** Return the BytesRef Comparator used to sort terms
-   *  provided by the iterator.  NOTE: this may return null
-   *  if there are no terms.  This method may be invoked
-   *  many times; it's best to cache a single instance &
-   *  reuse it. */
+   *  provided by the iterator.  This method will not return
+   *  null.  This method may be invoked many times; it's
+   *  best to cache a single instance & reuse it. */
   public abstract BytesRef.Comparator getComparator() throws IOException;
 
   /** Returns the number of documents containing the
@@ -58,25 +56,25 @@
   }
 
   // nocommit -- or maybe make a separate positions(...) method?
-  /** Get DocsEnum for the specified term.  Returns null if
-   *  the term does not exist. */
+  /** Get DocsEnum for the specified term.  This method will
+   *  not return null. */
   public DocsEnum docs(Bits skipDocs, BytesRef text, DocsEnum reuse) throws IOException {
     final TermsEnum termsEnum = getThreadTermsEnum();
     if (termsEnum.seek(text) == TermsEnum.SeekStatus.FOUND) {
       return termsEnum.docs(skipDocs, reuse);
     } else {
-      return null;
+      return DocsEnum.EMPTY;
     }
   }
 
-  /** Get DocsEnum for the specified term.  Returns null if
-   *  the term does not exist. */
+  /** Get DocsEnum for the specified term.  This method will
+   *  not return null. */ 
   public DocsAndPositionsEnum docsAndPositions(Bits skipDocs, BytesRef text, DocsAndPositionsEnum reuse) throws IOException {
     final TermsEnum termsEnum = getThreadTermsEnum();
     if (termsEnum.seek(text) == TermsEnum.SeekStatus.FOUND) {
       return termsEnum.docsAndPositions(skipDocs, reuse);
     } else {
-      return null;
+      return DocsAndPositionsEnum.EMPTY;
     }
   }
 
@@ -97,4 +95,38 @@
   protected void close() {
     threadEnums.close();
   }
+  public final static Terms[] EMPTY_ARRAY = new Terms[0];
+
+  /** Provides zero terms */
+  public final static Terms EMPTY = new Terms() {
+    @Override
+    public TermsEnum iterator() {
+      return TermsEnum.EMPTY;
+    }
+
+    @Override
+    public BytesRef.Comparator getComparator() {
+      return BytesRef.getUTF8SortedAsUTF16Comparator();
+    }
+
+    @Override
+    public int docFreq(BytesRef text) {
+      return 0;
+    }
+
+    @Override
+    public DocsEnum docs(Bits skipDocs, BytesRef text, DocsEnum reuse) {
+      return DocsEnum.EMPTY;
+    }
+
+    @Override
+    public DocsAndPositionsEnum docsAndPositions(Bits skipDocs, BytesRef text, DocsAndPositionsEnum reuse) {
+      return DocsAndPositionsEnum.EMPTY;
+    }
+
+    @Override
+    public long getUniqueTermCount() {
+      return 0;
+    }
+  };
 }
Index: src/java/org/apache/lucene/index/DocsAndPositionsEnum.java
===================================================================
--- src/java/org/apache/lucene/index/DocsAndPositionsEnum.java	(revision 919739)
+++ src/java/org/apache/lucene/index/DocsAndPositionsEnum.java	(working copy)
@@ -41,4 +41,47 @@
   public final int read(int[] docs, int[] freqs) {
     throw new UnsupportedOperationException();
   }
+
+  /** Provides zero docs */
+  public static final DocsAndPositionsEnum EMPTY = new DocsAndPositionsEnum() {
+    @Override
+    public int nextDoc() {
+      return NO_MORE_DOCS;
+    }
+
+    @Override
+    public int advance(int target) {
+      return NO_MORE_DOCS;
+    }
+
+    @Override
+    public int freq() {
+      throw new IllegalStateException("this method should never be called");
+    }
+
+    @Override
+    public int docID() {
+      throw new IllegalStateException("this method should never be called");
+    }
+
+    @Override
+    public int nextPosition() {
+      throw new IllegalStateException("this method should never be called");
+    }
+
+    @Override
+    public int getPayloadLength() {
+      throw new IllegalStateException("this method should never be called");
+    }
+
+    @Override
+    public BytesRef getPayload() {
+      throw new IllegalStateException("this method should never be called");
+    }
+
+    @Override
+    public boolean hasPayload() {
+      throw new IllegalStateException("this method should never be called");
+    }
+  };
 }
Index: src/java/org/apache/lucene/index/DocsEnum.java
===================================================================
--- src/java/org/apache/lucene/index/DocsEnum.java	(revision 919739)
+++ src/java/org/apache/lucene/index/DocsEnum.java	(working copy)
@@ -67,4 +67,33 @@
     }
     return count;
   }
+
+  /** Provides zero docs */
+  public static final DocsEnum EMPTY = new DocsEnum() {
+
+    @Override
+    public int nextDoc() {
+      return NO_MORE_DOCS;
+    }
+
+    @Override
+    public int advance(int target) {
+      return NO_MORE_DOCS;
+    }
+
+    @Override
+    public int freq() {
+      throw new IllegalStateException("this method should never be called");
+    }
+
+    @Override
+    public int docID() {
+      throw new IllegalStateException("this method should never be called");
+    }
+
+    @Override
+    public int read(int[] docs, int[] freqs) {
+      return 0;
+    }
+  };
 }
Index: src/java/org/apache/lucene/index/MultiReader.java
===================================================================
--- src/java/org/apache/lucene/index/MultiReader.java	(revision 919739)
+++ src/java/org/apache/lucene/index/MultiReader.java	(working copy)
@@ -30,7 +30,6 @@
 import org.apache.lucene.index.DirectoryReader.MultiTermPositions;  // deprecated
 import org.apache.lucene.search.Similarity;
 import org.apache.lucene.search.FieldCache; // not great (circular); used only to purge FieldCache entry on close
-import org.apache.lucene.util.MultiBits;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.ReaderUtil;
@@ -46,7 +45,8 @@
   private int maxDoc = 0;
   private int numDocs = -1;
   private boolean hasDeletions = false;
-  private MultiBits deletedDocs;
+  // nocommit remove:
+  //private MultiBits deletedDocs;
   //private Fields fields;
   
  /**
@@ -76,7 +76,7 @@
     this.subReaders =  subReaders.clone();
     starts = new int[subReaders.length + 1];    // build starts array
     decrefOnClose = new boolean[subReaders.length];
-    Bits[] subs = new Bits[subReaders.length];
+    //Bits[] subs = new Bits[subReaders.length];
 
     for (int i = 0; i < subReaders.length; i++) {
       starts[i] = maxDoc;
@@ -92,7 +92,7 @@
       if (subReaders[i].hasDeletions()) {
         hasDeletions = true;
       }
-      subs[i] = subReaders[i].getDeletedDocs();
+      //subs[i] = subReaders[i].getDeletedDocs();
 
       final ReaderUtil.Slice slice = new ReaderUtil.Slice(starts[i],
                                                           subReaders[i].maxDoc(),
@@ -101,11 +101,13 @@
     }
 
     starts[subReaders.length] = maxDoc;
+    /*
     if (hasDeletions) {
       deletedDocs = new MultiBits(subs, starts);
     } else {
       deletedDocs = null;
     }
+    */
   }
 
   @Override
@@ -115,7 +117,7 @@
 
   @Override
   public Fields fields() throws IOException {
-    throw new UnsupportedOperationException("please use MultiFields.getFields if you really need a top level Fields for this reader");
+    throw new UnsupportedOperationException("please use MultiFields.getFields if you really need a top level Fields (NOTE that it's usually better to work per segment instead)");
   }
 
   /**
@@ -162,11 +164,7 @@
   
   @Override
   public Bits getDeletedDocs() throws IOException {
-    if (subReaders.length == 1) {
-      return subReaders[0].getDeletedDocs();
-    } else {
-      return deletedDocs;
-    }
+    throw new UnsupportedOperationException("please use MultiFields.getDeletedDocs if you really need a top level Bits deletedDocs (NOTE that it's usually better to work per segment instead)");
   }
 
   /**
Index: src/java/org/apache/lucene/index/DirectoryReader.java
===================================================================
--- src/java/org/apache/lucene/index/DirectoryReader.java	(revision 919739)
+++ src/java/org/apache/lucene/index/DirectoryReader.java	(working copy)
@@ -39,7 +39,6 @@
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.ReaderUtil;
 import org.apache.lucene.util.BytesRef;
-import org.apache.lucene.util.MultiBits;
 
 import org.apache.lucene.search.FieldCache; // not great (circular); used only to purge FieldCache entry on close
 
@@ -352,6 +351,7 @@
     buffer.append('(');
     for(SegmentReader r : subReaders) {
       buffer.append(r);
+      buffer.append(' ');
     }
     buffer.append(')');
     return buffer.toString();
@@ -360,7 +360,7 @@
   private void initialize(SegmentReader[] subReaders) throws IOException {
     this.subReaders = subReaders;
     starts = new int[subReaders.length + 1];    // build starts array
-    Bits[] subs = new Bits[subReaders.length];
+    //Bits[] subs = new Bits[subReaders.length];
 
     final List<Fields> subFields = new ArrayList<Fields>();
     final List<ReaderUtil.Slice> fieldSlices = new ArrayList<ReaderUtil.Slice>();
@@ -371,7 +371,7 @@
 
       if (subReaders[i].hasDeletions()) {
         hasDeletions = true;
-        subs[i] = subReaders[i].getDeletedDocs();
+        //subs[i] = subReaders[i].getDeletedDocs();
       }
 
       final ReaderUtil.Slice slice = new ReaderUtil.Slice(starts[i], subReaders[i].maxDoc(), i);
@@ -385,19 +385,19 @@
     }
     starts[subReaders.length] = maxDoc;
 
+    /*
+    // nocommit remove:
     if (hasDeletions) {
       deletedDocs = new MultiBits(subs, starts);
     } else {
       deletedDocs = null;
     }
+    */
   }
 
-  private Bits deletedDocs;
-
   @Override
   public Bits getDeletedDocs() {
-    // nocommit -- maybe not supported?
-    return deletedDocs;
+    throw new UnsupportedOperationException("please use MultiFields.getDeletedDocs if you really need a top level Bits deletedDocs (NOTE that it's usually better to work per segment instead)");
   }
 
   @Override
@@ -722,7 +722,6 @@
   @Override
   public TermEnum terms() throws IOException {
     ensureOpen();
-    //nocommit: investigate this opto
     if (subReaders.length == 1) {
       // Optimize single segment case:
       return subReaders[0].terms();
@@ -786,9 +785,9 @@
   @Override
   public Fields fields() throws IOException {
     if (subReaders.length == 0) {
-      return null;
+      return Fields.EMPTY;
     } else {
-      throw new UnsupportedOperationException("please use MultiFields.getFields if you really need a top level Fields for this reader");
+      throw new UnsupportedOperationException("please use MultiFields.getFields if you really need a top level Fields (NOTE that it's usually better to work per segment instead)");
     }
   }
 
Index: src/java/org/apache/lucene/index/SegmentMerger.java
===================================================================
--- src/java/org/apache/lucene/index/SegmentMerger.java	(revision 919739)
+++ src/java/org/apache/lucene/index/SegmentMerger.java	(working copy)
@@ -175,14 +175,6 @@
 
     // Basic files
     for (String ext : IndexFileNames.COMPOUND_EXTENSIONS_NOT_CODEC) {
-       
-      // nocommit
-      /*
-      if (ext.equals(IndexFileNames.PROX_EXTENSION) && !hasProx())
-        continue;
-        
-      */
-
       if (mergeDocStores || (!ext.equals(IndexFileNames.FIELDS_EXTENSION) &&
                              !ext.equals(IndexFileNames.FIELDS_INDEX_EXTENSION)))
         files.add(IndexFileNames.segmentFileName(segment, ext));
@@ -571,12 +563,25 @@
     final List<Fields> fields = new ArrayList<Fields>();
     final List<IndexReader> subReaders = new ArrayList<IndexReader>();
     final List<ReaderUtil.Slice> slices = new ArrayList<ReaderUtil.Slice>();
+    final List<Bits> bits = new ArrayList<Bits>();
+    final List<Integer> bitsStarts = new ArrayList<Integer>();
 
     final int numReaders = readers.size();
     for(int i=0;i<numReaders;i++) {
-      docBase = ReaderUtil.gatherSubFields(subReaders, fields, slices, readers.get(i), docBase);
+      docBase = new ReaderUtil.Gather(readers.get(i)) {
+          @Override
+          protected void add(int base, IndexReader r) throws IOException {
+            subReaders.add(r);
+            fields.add(r.fields());
+            slices.add(new ReaderUtil.Slice(base, r.maxDoc(), fields.size()-1));
+            bits.add(r.getDeletedDocs());
+            bitsStarts.add(base);
+          }
+        }.run(docBase);
     }
 
+    bitsStarts.add(docBase);
+
     // we may gather more readers than mergeState.readerCount
     mergeState = new MergeState();
     mergeState.readers = subReaders;
@@ -592,7 +597,6 @@
     docBase = 0;
     int inputDocBase = 0;
 
-    final Bits[] subBits = new Bits[mergeState.readerCount];
     final int[] starts = new int[mergeState.readerCount+1];
 
     for(int i=0;i<mergeState.readerCount;i++) {
@@ -600,7 +604,6 @@
       final IndexReader reader = subReaders.get(i);
 
       starts[i] = inputDocBase;
-      subBits[i] = reader.getDeletedDocs();
 
       mergeState.delCounts[i] = reader.numDeletedDocs();
       mergeState.docBase[i] = docBase;
@@ -627,7 +630,10 @@
 
     final FieldsConsumer consumer = codec.fieldsConsumer(segmentWriteState);
 
-    mergeState.multiDeletedDocs = new MultiBits(subBits, starts);
+    // nocommit: somewhat stupid that we create this only to
+    // have it broken apart when we step through the docs
+    // enums in MultidDcsEnum.... is there a cleaner way?
+    mergeState.multiDeletedDocs = new MultiBits(bits, bitsStarts);
     
     try {
       consumer.merge(mergeState,
Index: src/java/org/apache/lucene/index/MultiFieldsEnum.java
===================================================================
--- src/java/org/apache/lucene/index/MultiFieldsEnum.java	(revision 919739)
+++ src/java/org/apache/lucene/index/MultiFieldsEnum.java	(working copy)
@@ -107,7 +107,7 @@
     }
 
     if (termsEnums.size() == 0) {
-      return null;
+      return TermsEnum.EMPTY;
     } else {
       return terms.reset(termsEnums.toArray(MultiTermsEnum.TermsEnumIndex.EMPTY_ARRAY));
     }
Index: src/java/org/apache/lucene/index/TermsHashPerField.java
===================================================================
--- src/java/org/apache/lucene/index/TermsHashPerField.java	(revision 919739)
+++ src/java/org/apache/lucene/index/TermsHashPerField.java	(working copy)
@@ -54,11 +54,6 @@
   private final BytesRef utf8;
   private BytesRef.Comparator termComp;
 
-  // nocommit -- move to thread level
-  // Used when comparing postings via termRefComp
-  private final BytesRef tr1 = new BytesRef();
-  private final BytesRef tr2 = new BytesRef();
-
   public TermsHashPerField(DocInverterPerField docInverterPerField, final TermsHashPerThread perThread, final TermsHashPerThread nextPerThread, final FieldInfo fieldInfo) {
     this.perThread = perThread;
     intPool = perThread.intPool;
@@ -68,9 +63,6 @@
     fieldState = docInverterPerField.fieldState;
     this.consumer = perThread.consumer.addField(this, fieldInfo);
 
-    tr1.length = 3*((int) (Short.MAX_VALUE));
-    tr2.length = 3*((int) (Short.MAX_VALUE));
-
     streamCount = consumer.getStreamCount();
     numPostingInt = 2*streamCount;
     utf8 = perThread.utf8;
@@ -219,14 +211,14 @@
   int comparePostings(RawPostingList p1, RawPostingList p2) {
 
     if (p1 == p2) {
-      // nocommit -- why does this happen again?
+      // Our quicksort does this, eg during partition
       return 0;
     }
 
-    termBytePool.setBytesRef(tr1, p1.textStart);
-    termBytePool.setBytesRef(tr2, p2.textStart);
+    termBytePool.setBytesRef(perThread.tr1, p1.textStart);
+    termBytePool.setBytesRef(perThread.tr2, p2.textStart);
 
-    return termComp.compare(tr1, tr2);
+    return termComp.compare(perThread.tr1, perThread.tr2);
   }
 
   /** Test whether the text for current RawPostingList p equals
Index: src/java/org/apache/lucene/index/TermsEnum.java
===================================================================
--- src/java/org/apache/lucene/index/TermsEnum.java	(revision 919739)
+++ src/java/org/apache/lucene/index/TermsEnum.java	(working copy)
@@ -91,19 +91,24 @@
    *  {@link SeekStatus#END}.*/
   public abstract int docFreq();
 
-  // nocommit -- clarify if this may return null
+  // nocommit -- need some way to state this postings does
+  // not store positions?
   // nocommit -- maybe require up front boolean doPositions?
   // nocommit -- or maybe make a separate positions(...) method?
   /** Get {@link DocsEnum} for the current term.  Do not
-   *  call this before calling next() for the first time,
-   *  after next() returns null or seek returns {@link
-   *  SeekStatus#END}.
+   *  call this before calling {@link #next} or {@link
+   *  #seek} for the first time.  This method will not
+   *  return null.
    *  
    * @param skipDocs set bits are documents that should not
    * be returned
    * @param reuse pass a prior DocsEnum for possible reuse */
   public abstract DocsEnum docs(Bits skipDocs, DocsEnum reuse) throws IOException;
 
+  /** Get {@link DocsAndPositionsEnum} for the current term.
+   *  Do not call this before calling {@link #next} or
+   *  {@link #seek} for the first time.  This method will
+   *  not return null. */
   public abstract DocsAndPositionsEnum docsAndPositions(Bits skipDocs, DocsAndPositionsEnum reuse) throws IOException;
 
   /** Return the {@link BytesRef} Comparator used to sort
@@ -128,7 +133,9 @@
     public SeekStatus seek(long ord) { return SeekStatus.END; }
     
     @Override
-    public BytesRef term() { return null; }
+    public BytesRef term() {
+      throw new IllegalStateException("this method should never be called");
+    }
 
     @Override
     public BytesRef.Comparator getComparator() {
@@ -137,21 +144,29 @@
     }
       
     @Override
-    public int docFreq() { return -1; }
+    public int docFreq() {
+      throw new IllegalStateException("this method should never be called");
+    }
       
     @Override
-    public long ord() { return -1; }
+    public long ord() {
+      throw new IllegalStateException("this method should never be called");
+    }
 
     @Override
-    public DocsEnum docs(Bits bits, DocsEnum reuse) { return null; }
+    public DocsEnum docs(Bits bits, DocsEnum reuse) {
+      throw new IllegalStateException("this method should never be called");
+    }
       
     @Override
     public DocsAndPositionsEnum docsAndPositions(Bits bits, DocsAndPositionsEnum reuse) {
-      return null;
+      throw new IllegalStateException("this method should never be called");
     }
       
     @Override
-    public BytesRef next() { return null; }
+    public BytesRef next() {
+      return null;
+    }
     
     @Override // make it synchronized here, to prevent double lazy init
     public synchronized AttributeSource attributes() {
Index: src/java/org/apache/lucene/index/MultiTermsEnum.java
===================================================================
--- src/java/org/apache/lucene/index/MultiTermsEnum.java	(revision 919739)
+++ src/java/org/apache/lucene/index/MultiTermsEnum.java	(working copy)
@@ -35,8 +35,8 @@
 public final class MultiTermsEnum extends TermsEnum {
     
   private final TermMergeQueue queue;
-  private final TermsEnumWithSlice[] subs;
-  private final TermsEnumWithSlice[] currentSubs;
+  private final TermsEnumWithSlice[] subs;        // all of our subs (one per sub-reader)
+  private final TermsEnumWithSlice[] currentSubs; // current subs that have at leat one term for this field
   private final TermsEnumWithSlice[] top;
   private final MultiDocsEnum.EnumWithSlice[] subDocs;
   private final MultiDocsAndPositionsEnum.EnumWithSlice[] subDocsAndPositions;
@@ -93,7 +93,7 @@
 
   /** The terms array must be newly created TermsEnum, ie
    *  {@link TermsEnum#next} has not yet been called. */
-  public MultiTermsEnum reset(TermsEnumIndex[] termsEnumsIndex) throws IOException {
+  public TermsEnum reset(TermsEnumIndex[] termsEnumsIndex) throws IOException {
     assert termsEnumsIndex.length <= top.length;
     numSubs = 0;
     numTop = 0;
@@ -128,7 +128,7 @@
     }
 
     if (queue.size() == 0) {
-      return null;
+      return TermsEnum.EMPTY;
     } else {
       return this;
     }
@@ -141,12 +141,12 @@
     for(int i=0;i<numSubs;i++) {
       final SeekStatus status = currentSubs[i].terms.seek(term);
       if (status == SeekStatus.FOUND) {
-        top[numTop++] = subs[i];
-        subs[i].current = term;
+        top[numTop++] = currentSubs[i];
+        currentSubs[i].current = term;
       } else if (status == SeekStatus.NOT_FOUND) {
-        subs[i].current = subs[i].terms.term();
-        assert subs[i].current != null;
-        queue.add(subs[i]);
+        currentSubs[i].current = currentSubs[i].terms.term();
+        assert currentSubs[i].current != null;
+        queue.add(currentSubs[i]);
       } else {
         // enum exhausted
       }
@@ -257,14 +257,16 @@
         // just pull the skipDocs from the sub reader, rather
         // than making the inefficient
         // Slice(Multi(sub-readers)):
-        final Bits b2 = multiSkipDocs.getMatchingSub(top[i].subSlice);
-        if (b2 != null) {
-          b = b2;
+        final MultiBits.SubResult sub = multiSkipDocs.getMatchingSub(top[i].subSlice);
+        if (sub.matches) {
+          b = sub.result;
         } else {
           // custom case: requested skip docs is foreign:
           // must slice it on every access
           b = new BitsSlice(skipDocs, top[i].subSlice);
         }
+      } else if (skipDocs != null) {
+        b = new BitsSlice(skipDocs, top[i].subSlice);
       } else {
         // no deletions
         b = null;
@@ -280,7 +282,7 @@
     }
 
     if (upto == 0) {
-      return null;
+      return DocsEnum.EMPTY;
     } else {
       return docsEnum.reset(subDocs, upto);
     }
@@ -311,19 +313,22 @@
       final Bits b;
 
       if (multiSkipDocs != null) {
-        // optimize for common case: requested skip docs is a
+        // Optimize for common case: requested skip docs is a
         // congruent sub-slice of MultiBits: in this case, we
         // just pull the skipDocs from the sub reader, rather
         // than making the inefficient
         // Slice(Multi(sub-readers)):
-        final Bits b2 = multiSkipDocs.getMatchingSub(top[i].subSlice);
-        if (b2 != null) {
-          b = b2;
+        final MultiBits.SubResult sub = multiSkipDocs.getMatchingSub(top[i].subSlice);
+        if (sub.matches) {
+          b = sub.result;
         } else {
           // custom case: requested skip docs is foreign:
-          // must slice it on every access
+          // must slice it on every access (very
+          // inefficient)
           b = new BitsSlice(skipDocs, top[i].subSlice);
         }
+      } else if (skipDocs != null) {
+        b = new BitsSlice(skipDocs, top[i].subSlice);
       } else {
         // no deletions
         b = null;
@@ -339,7 +344,7 @@
     }
 
     if (upto == 0) {
-      return null;
+      return DocsAndPositionsEnum.EMPTY;
     } else {
       return docsAndPositionsEnum.reset(subDocsAndPositions, upto);
     }
Index: src/java/org/apache/lucene/index/IndexReader.java
===================================================================
--- src/java/org/apache/lucene/index/IndexReader.java	(revision 919739)
+++ src/java/org/apache/lucene/index/IndexReader.java	(working copy)
@@ -21,7 +21,6 @@
 import org.apache.lucene.document.FieldSelector;
 import org.apache.lucene.search.Similarity;
 import org.apache.lucene.index.codecs.Codecs;
-import org.apache.lucene.index.codecs.Codec;
 import org.apache.lucene.store.*;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
@@ -881,7 +880,7 @@
   public abstract TermEnum terms() throws IOException;
 
   /** Flex API: returns {@link Fields} for this reader.
-   *  This may return  null if there are no fields.
+   *  This method will not return null.
    *
    * <p><b>NOTE</b>: if this is a multi reader ({@link
    * #getSequentialSubReaders} is not null) then this
@@ -918,12 +917,7 @@
    * account deleted documents that have not yet been
    * merged away. */
   public int docFreq(String field, BytesRef term) throws IOException {
-    final Terms terms = fields().terms(field);
-    if (terms != null) {
-      return terms.docFreq(term);
-    } else {
-      return 0;
-    }
+    return fields().terms(field).docFreq(term);
   }
 
   /** Returns an enumeration of all the documents which contain
@@ -949,63 +943,25 @@
   }
 
   public Terms terms(String field) throws IOException {
-    final Fields fields = fields();
-    if (fields != null) {
-      return fields.terms(field);
-    } else {
-      return null;
-    }
+    return fields().terms(field);
   }
 
   /** Returns {@link DocsEnum} for the specified field &
    *  term.  This may return null, for example if either the
    *  field or term does not exist. */
   public DocsEnum termDocsEnum(Bits skipDocs, String field, BytesRef term) throws IOException {
-
     assert field != null;
     assert term != null;
-    final Fields fields = fields();
-    if (fields != null) {
-      final Terms terms = fields.terms(field);
-      if (terms != null) {
-        if (Codec.DEBUG) {
-          System.out.println("ir.termDocsEnum field=" + field + " term=" + term + " terms=" + terms + " this=" + this);
-        }
-        final DocsEnum docs = terms.docs(skipDocs, term, null);
-        if (Codec.DEBUG) {
-          System.out.println("ir.termDocsEnum field=" + field + " docs=" +docs);
-        }
-        return docs;
-      }
-    }
-
-    return null;
+    return fields().terms(field).docs(skipDocs, term, null);
   }
 
   /** Returns {@link DocsAndPositionsEnum} for the specified
    *  field & term.  This may return null, for example if
    *  either the field or term does not exist. */
   public DocsAndPositionsEnum termPositionsEnum(Bits skipDocs, String field, BytesRef term) throws IOException {
-
     assert field != null;
     assert term != null;
-
-    final Fields fields = fields();
-    if (fields != null) {
-      final Terms terms = fields.terms(field);
-      if (terms != null) {
-        if (Codec.DEBUG) {
-          System.out.println("ir.termPositionsEnum field=" + field + " term=" + term + " terms=" + terms + " this=" + this);
-        }
-        final DocsAndPositionsEnum postings = terms.docsAndPositions(skipDocs, term, null);
-        if (Codec.DEBUG) {
-          System.out.println("ir.termPositionsEnum field=" + field + " postings=" +postings);
-        }
-        return postings;
-      }
-    }
-
-    return null;
+    return fields().terms(field).docsAndPositions(skipDocs, term, null);
   }
 
   /** Returns an unpositioned {@link TermDocs} enumerator.
@@ -1230,12 +1186,14 @@
     }
   }
 
-  /**
-   * Returns the {@link Bits} representing deleted docs.  A
-   * set bit indicates the doc ID has been deleted.  This
-   * method should return null when there are no deleted
-   * docs. */
   private Bits deletedDocsBits;
+
+  /** Returns the {@link Bits} representing deleted docs.  A
+   *  set bit indicates the doc ID has been deleted.  This
+   *  method should return null when there are no deleted
+   *  docs.
+   *
+   * @lucene.experimental */
   public Bits getDeletedDocs() throws IOException {
     if (deletedDocsBits == null) {
       deletedDocsBits = new DeletedDocsBits();
@@ -1431,13 +1389,25 @@
 
   private Fields fields;
 
-  /** lucene.experimental */
-  public void storeFields(Fields fields) {
+  /** lucene.internal */
+  void storeFields(Fields fields) {
     this.fields = fields;
   }
 
-  /** lucene.experimental */
-  public Fields retrieveFields() {
+  /** lucene.internal */
+  Fields retrieveFields() {
     return fields;
   }
+
+  private Bits storedDelDocs;
+
+  /** lucene.internal */
+  void storeDelDocs(Bits delDocs) {
+    this.storedDelDocs = delDocs;
+  }
+
+  /** lucene.internal */
+  Bits retrieveDelDocs() {
+    return storedDelDocs;
+  }
 }
Index: src/java/org/apache/lucene/index/TermsHashPerThread.java
===================================================================
--- src/java/org/apache/lucene/index/TermsHashPerThread.java	(revision 919739)
+++ src/java/org/apache/lucene/index/TermsHashPerThread.java	(working copy)
@@ -36,6 +36,10 @@
   final RawPostingList freePostings[] = new RawPostingList[256];
   int freePostingsCount;
 
+  // Used when comparing postings via termRefComp, in TermsHashPerField
+  final BytesRef tr1 = new BytesRef();
+  final BytesRef tr2 = new BytesRef();
+
   // Used by perField:
   final BytesRef utf8 = new BytesRef(10);
 
Index: src/java/org/apache/lucene/index/TermVectorsTermsWriterPerField.java
===================================================================
--- src/java/org/apache/lucene/index/TermVectorsTermsWriterPerField.java	(revision 919739)
+++ src/java/org/apache/lucene/index/TermVectorsTermsWriterPerField.java	(working copy)
@@ -95,9 +95,6 @@
 
   public void abort() {}
 
-  // nocommit -- should be @ thread level not field
-  private final BytesRef flushTerm = new BytesRef();
-
   /** Called once per field per document if term vectors
    *  are enabled, to write the vectors to
    *  RAMOutputStream, which is then quickly flushed to
@@ -109,6 +106,8 @@
 
     final int numPostings = termsHashPerField.numPostings;
 
+    final BytesRef flushTerm = perThread.flushTerm;
+
     assert numPostings >= 0;
 
     if (!doVectors || numPostings == 0)
@@ -128,8 +127,8 @@
 
     perThread.doc.addField(termsHashPerField.fieldInfo.number);
 
-    // nocommit -- should I sort by whatever terms dict is
-    // sorting by?
+    // TODO: we may want to make this sort in same order
+    // as Codec's terms dict?
     final RawPostingList[] postings = termsHashPerField.sortPostings(BytesRef.getUTF8SortedAsUTF16Comparator());
 
     tvf.writeVInt(numPostings);
Index: src/java/org/apache/lucene/index/Fields.java
===================================================================
--- src/java/org/apache/lucene/index/Fields.java	(revision 919739)
+++ src/java/org/apache/lucene/index/Fields.java	(working copy)
@@ -19,18 +19,33 @@
 
 import java.io.IOException;
 
-/** Access to fields and terms
+/** Flex API for access to fields and terms
  *  @lucene.experimental */
 
 public abstract class Fields {
 
-  public final static Fields[] EMPTY_ARRAY = new Fields[0];
-
   /** Returns an iterator that will step through all fields
-   *  names */
+   *  names.  This method will not return null.  */
   public abstract FieldsEnum iterator() throws IOException;
 
-  /** Get the {@link Terms} for this field */
+  /** Get the {@link Terms} for this field.  This method
+   * will not return null. */
   public abstract Terms terms(String field) throws IOException;
+
+  public final static Fields[] EMPTY_ARRAY = new Fields[0];
+
+  /** Provides zero fields */
+  public final static Fields EMPTY = new Fields() {
+
+    @Override
+    public FieldsEnum iterator() {
+      return FieldsEnum.EMPTY;
+    }
+
+    @Override
+    public Terms terms(String field) {
+      return Terms.EMPTY;
+    }
+  };
 }
 
Index: src/java/org/apache/lucene/index/codecs/MergeState.java
===================================================================
--- src/java/org/apache/lucene/index/codecs/MergeState.java	(revision 919739)
+++ src/java/org/apache/lucene/index/codecs/MergeState.java	(working copy)
@@ -34,6 +34,7 @@
   public int[] delCounts;                         // Deletion count per reader
   public int[] docBase;                           // New docID base per reader
   public int mergedDocCount;                      // Total # merged docs
+
   public Bits multiDeletedDocs;
 
   // Updated per field;
Index: src/java/org/apache/lucene/index/codecs/TermsConsumer.java
===================================================================
--- src/java/org/apache/lucene/index/codecs/TermsConsumer.java	(revision 919739)
+++ src/java/org/apache/lucene/index/codecs/TermsConsumer.java	(working copy)
@@ -51,6 +51,7 @@
   public void merge(MergeState mergeState, TermsEnum termsEnum) throws IOException {
 
     BytesRef term;
+    assert termsEnum != null;
 
     if (mergeState.fieldInfo.omitTermFreqAndPositions) {
       if (docsEnum == null) {
@@ -61,14 +62,14 @@
       MultiDocsEnum docsEnumIn = null;
 
       while((term = termsEnum.next()) != null) {
-        MultiDocsEnum docsEnumIn2 = (MultiDocsEnum) termsEnum.docs(mergeState.multiDeletedDocs, docsEnumIn);
-        if (docsEnumIn2 != null) {
-          docsEnumIn = docsEnumIn2;
-          docsEnum.reset(docsEnumIn);
-          final PostingsConsumer postingsConsumer = startTerm(term);
-          final int numDocs = postingsConsumer.merge(mergeState, docsEnum);
-          finishTerm(term, numDocs);
-        }
+        // nocommit -- dangerous?  what if .EMPTY is
+        // returned here?
+        docsEnumIn = (MultiDocsEnum) termsEnum.docs(mergeState.multiDeletedDocs, docsEnumIn);
+        assert docsEnumIn != null;
+        docsEnum.reset(docsEnumIn);
+        final PostingsConsumer postingsConsumer = startTerm(term);
+        final int numDocs = postingsConsumer.merge(mergeState, docsEnum);
+        finishTerm(term, numDocs);
       }
     } else {
       if (postingsEnum == null) {
@@ -77,14 +78,14 @@
       postingsEnum.setMergeState(mergeState);
       MultiDocsAndPositionsEnum postingsEnumIn = null;
       while((term = termsEnum.next()) != null) {
-        MultiDocsAndPositionsEnum postingsEnumIn2 = (MultiDocsAndPositionsEnum) termsEnum.docsAndPositions(mergeState.multiDeletedDocs, postingsEnumIn);
-        if (postingsEnumIn2 != null) {
-          postingsEnumIn = postingsEnumIn2;
-          postingsEnum.reset(postingsEnumIn);
-          final PostingsConsumer postingsConsumer = startTerm(term);
-          final int numDocs = postingsConsumer.merge(mergeState, postingsEnum);
-          finishTerm(term, numDocs);
-        }
+        // nocommit -- dangerous?  what if .EMPTY is
+        // returned here?
+        postingsEnumIn = (MultiDocsAndPositionsEnum) termsEnum.docsAndPositions(mergeState.multiDeletedDocs, postingsEnumIn);
+        assert postingsEnumIn != null;
+        postingsEnum.reset(postingsEnumIn);
+        final PostingsConsumer postingsConsumer = startTerm(term);
+        final int numDocs = postingsConsumer.merge(mergeState, postingsEnum);
+        finishTerm(term, numDocs);
       }
     }
   }
Index: src/java/org/apache/lucene/index/codecs/Codec.java
===================================================================
--- src/java/org/apache/lucene/index/codecs/Codec.java	(revision 919739)
+++ src/java/org/apache/lucene/index/codecs/Codec.java	(working copy)
@@ -59,6 +59,7 @@
   // nocommit -- add a "required capabilities" here; this
   // way merging could say only "TERMS_LINEAR_SCAN" but
   // searching would say "TERMS_RANDOM_ACCESS"?
+  // nocommit -- make a SegmentReadState (symmetric)?
   public abstract FieldsProducer fieldsProducer(Directory dir, FieldInfos fieldInfos, SegmentInfo si, int readBufferSize, int indexDivisor) throws IOException;
 
   /** Gathers files associated with this segment */
Index: src/java/org/apache/lucene/index/codecs/standard/StandardTermsDictReader.java
===================================================================
--- src/java/org/apache/lucene/index/codecs/standard/StandardTermsDictReader.java	(revision 919739)
+++ src/java/org/apache/lucene/index/codecs/standard/StandardTermsDictReader.java	(working copy)
@@ -205,7 +205,12 @@
     if (Codec.DEBUG) {
       System.out.println("stdr.terms field=" + field + " found=" + fields.get(field));
     }
-    return fields.get(field);
+    final Terms terms = fields.get(field);
+    if (terms == null) {
+      return Terms.EMPTY;
+    } else {
+      return terms;
+    }
   }
 
   // Iterates through all fields
@@ -552,6 +557,7 @@
           System.out.println("stdr.docs");
         }
         DocsEnum docsEnum = postingsReader.docs(fieldInfo, state, skipDocs, reuse);
+        assert docsEnum != null;
         if (Codec.DEBUG) {
           docsEnum.desc = fieldInfo.name + ":" + bytesReader.term.utf8ToString();
         }
@@ -564,13 +570,12 @@
           System.out.println("stdr.docsAndPositions omitTF=" + fieldInfo.omitTermFreqAndPositions);
         }
         if (fieldInfo.omitTermFreqAndPositions) {
-          return null;
+          return DocsAndPositionsEnum.EMPTY;
         } else {
           DocsAndPositionsEnum postingsEnum = postingsReader.docsAndPositions(fieldInfo, state, skipDocs, reuse);
+          assert postingsEnum != null;
           if (Codec.DEBUG) {
-            if (postingsEnum != null) {
-              postingsEnum.desc = fieldInfo.name + ":" + bytesReader.term.utf8ToString();
-            }
+            postingsEnum.desc = fieldInfo.name + ":" + bytesReader.term.utf8ToString();
           }
           if (Codec.DEBUG) {
             Codec.debug("  return enum=" + postingsEnum);
Index: src/java/org/apache/lucene/index/codecs/standard/StandardPostingsReaderImpl.java
===================================================================
--- src/java/org/apache/lucene/index/codecs/standard/StandardPostingsReaderImpl.java	(revision 919739)
+++ src/java/org/apache/lucene/index/codecs/standard/StandardPostingsReaderImpl.java	(working copy)
@@ -165,7 +165,8 @@
   @Override
   public DocsEnum docs(FieldInfo fieldInfo, TermState termState, Bits skipDocs, DocsEnum reuse) throws IOException {
     final SegmentDocsEnum docsEnum;
-    if (reuse == null) {
+    // nocommit messy
+    if (reuse == null || !(reuse instanceof SegmentDocsEnum)) {
       docsEnum = new SegmentDocsEnum(freqIn);
     } else {
       docsEnum = (SegmentDocsEnum) reuse;
@@ -176,10 +177,10 @@
   @Override
   public DocsAndPositionsEnum docsAndPositions(FieldInfo fieldInfo, TermState termState, Bits skipDocs, DocsAndPositionsEnum reuse) throws IOException {
     if (fieldInfo.omitTermFreqAndPositions) {
-      return null;
+      return DocsAndPositionsEnum.EMPTY;
     }
     final SegmentDocsAndPositionsEnum docsEnum;
-    if (reuse == null) {
+    if (reuse == null || !(reuse instanceof SegmentDocsAndPositionsEnum)) {
       docsEnum = new SegmentDocsAndPositionsEnum(freqIn, proxIn);
     } else {
       docsEnum = (SegmentDocsAndPositionsEnum) reuse;
Index: src/java/org/apache/lucene/index/codecs/FieldsConsumer.java
===================================================================
--- src/java/org/apache/lucene/index/codecs/FieldsConsumer.java	(revision 919739)
+++ src/java/org/apache/lucene/index/codecs/FieldsConsumer.java	(working copy)
@@ -20,7 +20,6 @@
 import org.apache.lucene.index.FieldInfo;
 import org.apache.lucene.index.Fields;
 import org.apache.lucene.index.FieldsEnum;
-import org.apache.lucene.index.TermsEnum;
 
 import java.io.IOException;
 
@@ -41,14 +40,12 @@
 
   public void merge(MergeState mergeState, Fields fields) throws IOException {
     FieldsEnum fieldsEnum = fields.iterator();
+    assert fieldsEnum != null;
     String field;
     while((field = fieldsEnum.next()) != null) {
       mergeState.fieldInfo = mergeState.fieldInfos.fieldInfo(field);
       final TermsConsumer termsConsumer = addField(mergeState.fieldInfo);
-      final TermsEnum termsEnum = fieldsEnum.terms();
-      if (termsEnum != null) {
-        termsConsumer.merge(mergeState, termsEnum);
-      }
+      termsConsumer.merge(mergeState, fieldsEnum.terms());
     }
   }
 }
Index: src/java/org/apache/lucene/index/codecs/preflex/SegmentTermDocs.java
===================================================================
--- src/java/org/apache/lucene/index/codecs/preflex/SegmentTermDocs.java	(revision 919739)
+++ src/java/org/apache/lucene/index/codecs/preflex/SegmentTermDocs.java	(working copy)
@@ -144,8 +144,10 @@
         doc += docCode >>> 1;       // shift off low bit
         if ((docCode & 1) != 0)       // if low bit is set
           freq = 1;         // freq is one
-        else
+        else {
           freq = freqStream.readVInt();     // else read freq
+          assert freq != 1;
+        }
       }
       
       count++;
Index: src/java/org/apache/lucene/index/codecs/preflex/PreFlexFields.java
===================================================================
--- src/java/org/apache/lucene/index/codecs/preflex/PreFlexFields.java	(revision 919739)
+++ src/java/org/apache/lucene/index/codecs/preflex/PreFlexFields.java	(working copy)
@@ -124,7 +124,7 @@
     if (fi != null) {
       return new PreTerms(fi);
     } else {
-      return null;
+      return Terms.EMPTY;
     }
   }
 
@@ -427,6 +427,7 @@
     }
 
     public DocsAndPositionsEnum reset(SegmentTermEnum termEnum, Bits skipDocs) throws IOException {
+      //new Throwable().printStackTrace(System.out);
       pos.setSkipDocs(skipDocs);
       pos.seek(termEnum);
       return this;
Index: src/java/org/apache/lucene/index/MultiFields.java
===================================================================
--- src/java/org/apache/lucene/index/MultiFields.java	(revision 919739)
+++ src/java/org/apache/lucene/index/MultiFields.java	(working copy)
@@ -25,7 +25,7 @@
 import org.apache.lucene.util.ReaderUtil;
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
-import org.apache.lucene.index.codecs.Codec;
+import org.apache.lucene.util.MultiBits;
 
 /**
  * Exposes flex API, merged from flex API of sub-segments.
@@ -45,8 +45,9 @@
 public final class MultiFields extends Fields {
   private final Fields[] subs;
   private final ReaderUtil.Slice[] subSlices;
-  private final Map<String,MultiTerms> terms = new HashMap<String,MultiTerms>();
+  private final Map<String,Terms> terms = new HashMap<String,Terms>();
 
+  /**  This method will not return null.*/
   public static Fields getFields(IndexReader r) throws IOException {
     final IndexReader[] subs = r.getSequentialSubReaders();
     if (subs == null) {
@@ -61,10 +62,17 @@
       
         final List<Fields> fields = new ArrayList<Fields>();
         final List<ReaderUtil.Slice> slices = new ArrayList<ReaderUtil.Slice>();
-        ReaderUtil.gatherSubFields(null, fields, slices, r, 0);
 
+        new ReaderUtil.Gather(r) {
+          @Override
+          protected void add(int base, IndexReader r) throws IOException {
+            fields.add(r.fields());
+            slices.add(new ReaderUtil.Slice(base, r.maxDoc(), fields.size()-1));
+          }
+        }.run();
+
         if (fields.size() == 0) {
-          return null;
+          return Fields.EMPTY;
         } else if (fields.size() == 1) {
           currentFields = fields.get(0);
         } else {
@@ -77,66 +85,64 @@
     }
   }
 
-  public static Terms getTerms(IndexReader r, String field) throws IOException {
-    final Fields fields = getFields(r);
-    if (fields != null) {
-      return fields.terms(field);
+  public static Bits getDeletedDocs(IndexReader r) throws IOException {
+    Bits result;
+    if (r.hasDeletions()) {
+
+      result = r.retrieveDelDocs();
+      if (result == null) {
+
+        final List<Bits> bits = new ArrayList<Bits>();
+        final List<Integer> starts = new ArrayList<Integer>();
+        final List<Bits> nulls = new ArrayList<Bits>();
+
+        final int maxDoc = new ReaderUtil.Gather(r) {
+          @Override
+          protected void add(int base, IndexReader r) throws IOException {
+            // record all delDocs, even if they are null
+            bits.add(r.getDeletedDocs());
+            starts.add(base);
+          }
+        }.run();
+        starts.add(maxDoc);
+
+        assert bits.size() > 0;
+        if (bits.size() == 1) {
+          // Only one actual sub reader -- optimize this case
+          result = bits.get(0);
+        } else {
+          result = new MultiBits(bits, starts);
+        }
+        r.storeDelDocs(result);
+      }
     } else {
-      return null;
+      result = null;
     }
+
+    return result;
   }
 
+  /**  This method will not return null.*/
+  public static Terms getTerms(IndexReader r, String field) throws IOException {
+    return getFields(r).terms(field);
+  }
+
   /** Returns {@link DocsEnum} for the specified field &
-   *  term.  This may return null, for example if either the
-   *  field or term does not exist. */
+   *  term.  This method will not return null. */
   public static DocsEnum getTermDocsEnum(IndexReader r, Bits skipDocs, String field, BytesRef term) throws IOException {
-
     assert field != null;
     assert term != null;
-    final Fields fields = getFields(r);
-    if (fields != null) {
-      final Terms terms = fields.terms(field);
-      if (terms != null) {
-        if (Codec.DEBUG) {
-          System.out.println("mf.termDocsEnum field=" + field + " term=" + term + " terms=" + terms);
-        }
-        final DocsEnum docs = terms.docs(skipDocs, term, null);
-        if (Codec.DEBUG) {
-          System.out.println("mf.termDocsEnum field=" + field + " docs=" +docs);
-        }
-        return docs;
-      }
-    }
-
-    return null;
+    return getFields(r).terms(field).docs(skipDocs, term, null);
   }
 
   /** Returns {@link DocsAndPositionsEnum} for the specified
-   *  field & term.  This may return null, for example if
-   *  either the field or term does not exist. */
+   *  field & term.  This method will not return null. */
   public static DocsAndPositionsEnum getTermPositionsEnum(IndexReader r, Bits skipDocs, String field, BytesRef term) throws IOException {
     assert field != null;
     assert term != null;
-
-    final Fields fields = getFields(r);
-    if (fields != null) {
-      final Terms terms = fields.terms(field);
-      if (terms != null) {
-        if (Codec.DEBUG) {
-          System.out.println("mf.termPositionsEnum field=" + field + " term=" + term + " terms=" + terms);
-        }
-        final DocsAndPositionsEnum postings = terms.docsAndPositions(skipDocs, term, null);
-        if (Codec.DEBUG) {
-          System.out.println("mf.termPositionsEnum field=" + field + " postings=" +postings);
-        }
-        return postings;
-      }
-    }
-
-    return null;
+    return getFields(r).terms(field).docsAndPositions(skipDocs, term, null);
   }
 
-
   public MultiFields(Fields[] subs, ReaderUtil.Slice[] subSlices) {
     this.subs = subs;
     this.subSlices = subSlices;
@@ -148,14 +154,11 @@
     final List<FieldsEnum> fieldsEnums = new ArrayList<FieldsEnum>();
     final List<ReaderUtil.Slice> fieldsSlices = new ArrayList<ReaderUtil.Slice>();
     for(int i=0;i<subs.length;i++) {
-      final FieldsEnum subFieldsEnum = subs[i].iterator();
-      if (subFieldsEnum != null) {
-        fieldsEnums.add(subFieldsEnum);
-        fieldsSlices.add(subSlices[i]);
-      }
+      fieldsEnums.add(subs[i].iterator());
+      fieldsSlices.add(subSlices[i]);
     }
     if (fieldsEnums.size() == 0) {
-      return null;
+      return FieldsEnum.EMPTY;
     } else {
       return new MultiFieldsEnum(fieldsEnums.toArray(FieldsEnum.EMPTY_ARRAY),
                                  fieldsSlices.toArray(ReaderUtil.Slice.EMPTY_ARRAY));
@@ -165,7 +168,7 @@
   @Override
   public Terms terms(String field) throws IOException {
 
-    final MultiTerms result;
+    final Terms result;
 
     if (!terms.containsKey(field)) {
 
@@ -176,15 +179,11 @@
 
       // Gather all sub-readers that share this field
       for(int i=0;i<subs.length;i++) {
-        Terms subTerms = subs[i].terms(field);
-        if (subTerms != null) {
-          subs2.add(subTerms);
-          slices2.add(subSlices[i]);
-        }
+        subs2.add(subs[i].terms(field));
+        slices2.add(subSlices[i]);
       }
       if (subs2.size() == 0) {
-        result = null;
-        terms.put(field, null);
+        result = Terms.EMPTY;
       } else {
         result = new MultiTerms(subs2.toArray(Terms.EMPTY_ARRAY),
                                 slices2.toArray(ReaderUtil.Slice.EMPTY_ARRAY));
Index: src/java/org/apache/lucene/index/TermVectorsTermsWriterPerThread.java
===================================================================
--- src/java/org/apache/lucene/index/TermVectorsTermsWriterPerThread.java	(revision 919739)
+++ src/java/org/apache/lucene/index/TermVectorsTermsWriterPerThread.java	(working copy)
@@ -17,11 +17,14 @@
  * limitations under the License.
  */
 
+import org.apache.lucene.util.BytesRef;
+
 final class TermVectorsTermsWriterPerThread extends TermsHashConsumerPerThread {
 
   final TermVectorsTermsWriter termsWriter;
   final TermsHashPerThread termsHashPerThread;
   final DocumentsWriter.DocState docState;
+  final BytesRef flushTerm = new BytesRef();
 
   TermVectorsTermsWriter.PerDoc doc;
 
Index: src/java/org/apache/lucene/util/ReaderUtil.java
===================================================================
--- src/java/org/apache/lucene/util/ReaderUtil.java	(revision 919739)
+++ src/java/org/apache/lucene/util/ReaderUtil.java	(working copy)
@@ -22,7 +22,6 @@
 import java.io.IOException;
 
 import org.apache.lucene.index.IndexReader;
-import org.apache.lucene.index.Fields;
 
 /**
  * Common util methods for dealing with {@link IndexReader}s.
@@ -54,35 +53,53 @@
    * @param allSubReaders
    * @param reader
    */
-  public static void gatherSubReaders(List<IndexReader> allSubReaders, IndexReader reader) {
-    IndexReader[] subReaders = reader.getSequentialSubReaders();
-    if (subReaders == null) {
-      // Add the reader itself, and do not recurse
-      allSubReaders.add(reader);
-    } else {
-      for (int i = 0; i < subReaders.length; i++) {
-        gatherSubReaders(allSubReaders, subReaders[i]);
-      }
+
+  public static void gatherSubReaders(final List<IndexReader> allSubReaders, IndexReader reader) {
+    try {
+      new Gather(reader) {
+        @Override
+          protected void add(int base, IndexReader r) {
+          allSubReaders.add(r);
+        }
+      }.run();
+    } catch (IOException ioe) {
+      // won't happen
+      throw new RuntimeException(ioe);
     }
   }
 
-  public static int gatherSubFields(List<IndexReader> readers, List<Fields> fields, List<Slice> slices, IndexReader reader, int base) throws IOException {
-    IndexReader[] subReaders = reader.getSequentialSubReaders();
-    if (subReaders == null) {
-      // Add the reader's fields
-      if (readers != null) {
-        readers.add(reader);
+  public static abstract class Gather {
+    private final IndexReader topReader;
+
+    public Gather(IndexReader r) {
+      topReader = r;
+    }
+
+    public int run() throws IOException {
+      return run(0, topReader);
+    }
+
+    public int run(int docBase) throws IOException {
+      return run(docBase, topReader);
+    }
+
+    private int run(int base, IndexReader reader) throws IOException {
+      IndexReader[] subReaders = reader.getSequentialSubReaders();
+      if (subReaders == null) {
+        // atomic reader
+        add(base, reader);
+        base += reader.maxDoc();
+      } else {
+        // composite reader
+        for (int i = 0; i < subReaders.length; i++) {
+          base = run(base, subReaders[i]);
+        }
       }
-      fields.add(reader.fields());
-      slices.add(new Slice(base, reader.maxDoc(), fields.size()-1));
-      base += reader.maxDoc();
-    } else {
-      for (int i = 0; i < subReaders.length; i++) {
-        base = gatherSubFields(readers, fields, slices, subReaders[i], base);
-      }
+
+      return base;
     }
 
-    return base;
+    protected abstract void add(int base, IndexReader r) throws IOException;
   }
 
   /**
Index: src/java/org/apache/lucene/util/Bits.java
===================================================================
--- src/java/org/apache/lucene/util/Bits.java	(revision 919739)
+++ src/java/org/apache/lucene/util/Bits.java	(working copy)
@@ -17,7 +17,13 @@
  * limitations under the License.
  */
 
+/**
+ * @lucene.experimental
+ */
+
 public interface Bits {
   public boolean get(int index);
   public int length();
+
+  public static final Bits[] EMPTY_ARRAY = new Bits[0];
 }
Index: src/java/org/apache/lucene/util/MultiBits.java
===================================================================
--- src/java/org/apache/lucene/util/MultiBits.java	(revision 919739)
+++ src/java/org/apache/lucene/util/MultiBits.java	(working copy)
@@ -17,21 +17,30 @@
  * limitations under the License.
  */
 
+import java.util.List;
+
 /**
  * Concatenates multiple Bits together, on every lookup.
  *
  * <p><b>NOTE</b>: This is very costly, as every lookup must
  * do a binary search to locate the right sub-reader.
+ *
+ * @lucene.experimental
  */
+
 public final class MultiBits implements Bits {
   private final Bits[] subs;
 
   // length is 1+subs.length (the last entry has the maxDoc):
   private final int[] starts;
 
-  public MultiBits(Bits[] subs, int[] starts) {
-    this.subs = subs;
-    this.starts = starts;
+  public MultiBits(List<Bits> bits, List<Integer> starts) {
+    assert starts.size() == 1+bits.size();
+    this.subs = bits.toArray(Bits.EMPTY_ARRAY);
+    this.starts = new int[starts.size()];
+    for(int i=0;i<this.starts.length;i++) {
+      this.starts[i] = starts.get(i);
+    }
   }
 
   private boolean checkLength(int reader, int doc) {
@@ -42,6 +51,7 @@
 
   public boolean get(int doc) {
     final int reader = ReaderUtil.subIndex(doc, starts);
+    assert reader != -1;
     final Bits bits = subs[reader];
     if (bits == null) {
       return false;
@@ -51,13 +61,24 @@
     }
   }
 
-  public Bits getMatchingSub(ReaderUtil.Slice slice) {
+  public final static class SubResult {
+    public boolean matches;
+    public Bits result;
+  }
+
+  private final SubResult subResult = new SubResult();
+
+  public SubResult getMatchingSub(ReaderUtil.Slice slice) {
     int reader = ReaderUtil.subIndex(slice.start, starts);
+    assert reader != -1;
+    assert reader < subs.length: "slice=" + slice + " starts[-1]=" + starts[starts.length-1];
     if (starts[reader] == slice.start && starts[1+reader] == slice.start+slice.length) {
-      return subs[reader];
+      subResult.matches = true;
+      subResult.result = subs[reader];
     } else {
-      return null;
+      subResult.matches = false;
     }
+    return subResult;
   }
 
   public int length() {
Index: contrib/benchmark/src/test/org/apache/lucene/benchmark/byTask/TestPerfTasksLogic.java
===================================================================
--- contrib/benchmark/src/test/org/apache/lucene/benchmark/byTask/TestPerfTasksLogic.java	(revision 919739)
+++ contrib/benchmark/src/test/org/apache/lucene/benchmark/byTask/TestPerfTasksLogic.java	(working copy)
@@ -478,7 +478,7 @@
       TermsEnum terms = fields.terms();
       DocsEnum docs = null;
       while(terms.next() != null) {
-        docs = terms.docs(reader.getDeletedDocs(), docs);
+        docs = terms.docs(MultiFields.getDeletedDocs(reader), docs);
         while(docs.nextDoc() != docs.NO_MORE_DOCS) {
           totalTokenCount2 += docs.freq();
         }
Index: contrib/misc/src/java/org/apache/lucene/index/MultiPassIndexSplitter.java
===================================================================
--- contrib/misc/src/java/org/apache/lucene/index/MultiPassIndexSplitter.java	(revision 919739)
+++ contrib/misc/src/java/org/apache/lucene/index/MultiPassIndexSplitter.java	(working copy)
@@ -202,6 +202,8 @@
       if (oldDels != null) {
         dels.or(oldDels);
       }
+      // nocommit -- not good that this class has to do this...
+      storeDelDocs(null);
     }
 
     @Override
Index: contrib/misc/src/java/org/apache/lucene/index/TermVectorAccessor.java
===================================================================
--- contrib/misc/src/java/org/apache/lucene/index/TermVectorAccessor.java	(revision 919739)
+++ contrib/misc/src/java/org/apache/lucene/index/TermVectorAccessor.java	(working copy)
@@ -100,7 +100,7 @@
       positions.clear();
     }
 
-    final Bits delDocs = indexReader.getDeletedDocs();
+    final Bits delDocs = MultiFields.getDeletedDocs(indexReader);
 
     Terms terms = MultiFields.getTerms(indexReader, field);
     boolean anyTerms = false;
Index: contrib/queries/src/java/org/apache/lucene/search/DuplicateFilter.java
===================================================================
--- contrib/queries/src/java/org/apache/lucene/search/DuplicateFilter.java	(revision 919739)
+++ contrib/queries/src/java/org/apache/lucene/search/DuplicateFilter.java	(working copy)
@@ -22,6 +22,7 @@
 import org.apache.lucene.index.Terms;
 import org.apache.lucene.index.DocsEnum;
 import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.index.MultiFields;
 import org.apache.lucene.util.OpenBitSet;
 import org.apache.lucene.util.Bits;
 
@@ -83,7 +84,7 @@
 	
   private OpenBitSet correctBits(IndexReader reader) throws IOException {
     OpenBitSet bits = new OpenBitSet(reader.maxDoc()); //assume all are INvalid
-    final Bits delDocs = reader.getDeletedDocs();
+    final Bits delDocs = MultiFields.getDeletedDocs(reader);
     Terms terms = reader.fields().terms(fieldName);
     if (terms != null) {
       TermsEnum termsEnum = terms.iterator();
@@ -121,7 +122,7 @@
 		
     OpenBitSet bits=new OpenBitSet(reader.maxDoc());
     bits.set(0,reader.maxDoc()); //assume all are valid
-    final Bits delDocs = reader.getDeletedDocs();
+    final Bits delDocs = MultiFields.getDeletedDocs(reader);
     Terms terms = reader.fields().terms(fieldName);
     if (terms != null) {
       TermsEnum termsEnum = terms.iterator();