Index: modules/grouping/src/java/org/apache/lucene/search/grouping/dv/DVAllGroupsCollector.java
===================================================================
--- modules/grouping/src/java/org/apache/lucene/search/grouping/dv/DVAllGroupsCollector.java	(revision 1293879)
+++ modules/grouping/src/java/org/apache/lucene/search/grouping/dv/DVAllGroupsCollector.java	(working copy)
@@ -20,7 +20,6 @@
 import org.apache.lucene.index.AtomicReaderContext;
 import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.DocValues.Type; // javadocs
-import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.search.grouping.AbstractAllGroupsCollector;
 import org.apache.lucene.util.SentinelIntSet;
 import org.apache.lucene.util.BytesRef;
@@ -239,7 +238,7 @@
 
       ordSet.clear();
       for (BytesRef countedGroup : groups) {
-        int ord = this.source.getByValue(countedGroup, spare);
+        int ord = this.source.getOrdByValue(countedGroup, spare);
         if (ord >= 0) {
           ordSet.put(ord);
         }
Index: modules/grouping/src/java/org/apache/lucene/search/grouping/dv/DVSecondPassGroupingCollector.java
===================================================================
--- modules/grouping/src/java/org/apache/lucene/search/grouping/dv/DVSecondPassGroupingCollector.java	(revision 1293879)
+++ modules/grouping/src/java/org/apache/lucene/search/grouping/dv/DVSecondPassGroupingCollector.java	(working copy)
@@ -20,7 +20,6 @@
 import org.apache.lucene.index.AtomicReaderContext;
 import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.DocValues.Type; // javadocs
-import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.search.Sort;
 import org.apache.lucene.search.grouping.AbstractSecondPassGroupingCollector;
 import org.apache.lucene.search.grouping.SearchGroup;
@@ -215,7 +214,7 @@
 
       ordSet.clear();
       for (SearchGroupDocs<BytesRef> group : groupMap.values()) {
-        int ord = this.source.getByValue(group.groupValue, spare);
+        int ord = this.source.getOrdByValue(group.groupValue, spare);
         if (ord >= 0) {
           groupDocs[ordSet.put(ord)] = group;
         }
Index: lucene/core/src/test/org/apache/lucene/codecs/lucene40/values/TestDocValues.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/codecs/lucene40/values/TestDocValues.java	(revision 1293879)
+++ lucene/core/src/test/org/apache/lucene/codecs/lucene40/values/TestDocValues.java	(working copy)
@@ -114,7 +114,7 @@
           assertEquals("doc " + idx, values[idx], ss.getByOrd(ss.ord(idx),
               bytesRef).utf8ToString());
          int ord = ss
-              .getByValue(new BytesRef(values[idx]), new BytesRef());
+              .getOrdByValue(new BytesRef(values[idx]), new BytesRef());
           assertTrue(ord >= 0);
           assertEquals(ss.ord(idx), ord);
         }
@@ -125,7 +125,7 @@
         final int valueCount = ss.getValueCount();
         for (int i = 0; i < 1000; i++) {
           BytesRef bytesValue = new BytesRef(_TestUtil.randomFixedByteLengthUnicodeString(random, fixedSize? fixedLength : 1 + random.nextInt(39)));
-          int ord = ss.getByValue(bytesValue, new BytesRef());
+          int ord = ss.getOrdByValue(bytesValue, new BytesRef());
           if (ord >= 0) {
             assertTrue(bytesValue
                 .bytesEquals(ss.getByOrd(ord, bytesRef)));
Index: lucene/core/src/test/org/apache/lucene/search/TestSort.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestSort.java	(revision 1293879)
+++ lucene/core/src/test/org/apache/lucene/search/TestSort.java	(working copy)
@@ -20,27 +20,32 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.BitSet;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Random;
+import java.util.Set;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 
 import org.apache.lucene.analysis.MockAnalyzer;
 import org.apache.lucene.codecs.Codec;
+import org.apache.lucene.document.DocValuesField;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.document.Field;
 import org.apache.lucene.document.FieldType;
-import org.apache.lucene.document.DocValuesField;
 import org.apache.lucene.document.StringField;
 import org.apache.lucene.document.TextField;
 import org.apache.lucene.index.AtomicReaderContext;
 import org.apache.lucene.index.CorruptIndexException;
+import org.apache.lucene.index.DocValues;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.IndexWriter;
 import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.index.MultiReader;
 import org.apache.lucene.index.RandomIndexWriter;
 import org.apache.lucene.index.Term;
-import org.apache.lucene.index.DocValues;
 import org.apache.lucene.search.BooleanClause.Occur;
 import org.apache.lucene.search.FieldValueHitQueue.Entry;
 import org.apache.lucene.store.Directory;
@@ -48,6 +53,7 @@
 import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.DocIdBitSet;
+import org.apache.lucene.util.FixedBitSet;
 import org.apache.lucene.util.LuceneTestCase;
 import org.apache.lucene.util._TestUtil;
 import org.junit.BeforeClass;
@@ -1294,4 +1300,151 @@
     reader.close();
     indexStore.close();
   }
+
+  private static class RandomFilter extends Filter {
+    private final Random random;
+    private float density;
+    private final List<BytesRef> docValues;
+    public final List<BytesRef> matchValues = Collections.synchronizedList(new ArrayList<BytesRef>());
+
+    // density should be 0.0 ... 1.0
+    public RandomFilter(Random random, float density, List<BytesRef> docValues) {
+      this.random = random;
+      this.density = density;
+      this.docValues = docValues;
+    }
+
+    @Override
+    public DocIdSet getDocIdSet(AtomicReaderContext context, Bits acceptDocs) throws IOException {
+      final int maxDoc = context.reader().maxDoc();
+      final DocValues.Source idSource = context.reader().docValues("id").getSource();
+      assertNotNull(idSource);
+      final FixedBitSet bits = new FixedBitSet(maxDoc);
+      for(int docID=0;docID<maxDoc;docID++) {
+        if (random.nextFloat() <= density && (acceptDocs == null || acceptDocs.get(docID))) {
+          bits.set(docID);
+          //System.out.println("  acc id=" + idSource.getInt(docID) + " docID=" + docID);
+          matchValues.add(docValues.get((int) idSource.getInt(docID)));
+        }
+      }
+
+      return bits;
+    }
+  }
+
+  public void testRandomStringSort() throws Exception {
+    final int NUM_DOCS = atLeast(100);
+    final Directory dir = newDirectory();
+    final RandomIndexWriter writer = new RandomIndexWriter(random, dir);
+    final boolean allowDups = random.nextBoolean();
+    final Set<String> seen = new HashSet<String>();
+    final int maxLength = _TestUtil.nextInt(random, 5, 100);
+    if (VERBOSE) {
+      System.out.println("TEST: NUM_DOCS=" + NUM_DOCS + " maxLength=" + maxLength + " allowDups=" + allowDups);
+    }
+    int numDocs = 0;
+    final List<BytesRef> docValues = new ArrayList<BytesRef>();
+    // TODO: deletions
+    while (numDocs < NUM_DOCS) {
+      final String s;
+      if (random.nextBoolean()) {
+        s = _TestUtil.randomSimpleString(random, maxLength);
+      } else {
+        s = _TestUtil.randomUnicodeString(random, maxLength);
+      }
+      final BytesRef br = new BytesRef(s);
+
+      if (!allowDups) {
+        if (seen.contains(s)) {
+          continue;
+        }
+        seen.add(s);
+      }
+
+      if (VERBOSE) {
+        System.out.println("  " + numDocs + ": s=" + s);
+      }
+      
+      final Document doc = new Document();
+      doc.add(new DocValuesField("stringdv", br, DocValues.Type.BYTES_VAR_SORTED));
+      doc.add(newField("string", s, StringField.TYPE_UNSTORED));
+      doc.add(new DocValuesField("id", numDocs, DocValues.Type.VAR_INTS));
+      docValues.add(br);
+      writer.addDocument(doc);
+      numDocs++;
+
+      if (random.nextInt(40) == 17) {
+        // force flush
+        writer.getReader().close();
+      }
+    }
+
+    final IndexReader r = writer.getReader();
+    writer.close();
+    if (VERBOSE) {
+      System.out.println("  reader=" + r);
+    }
+    
+    final IndexSearcher s = newSearcher(r, false);
+    final int ITERS = atLeast(100);
+    for(int iter=0;iter<ITERS;iter++) {
+      final boolean reverse = random.nextBoolean();
+      final TopFieldDocs hits;
+      final SortField sf;
+      if (random.nextBoolean()) {
+        sf = new SortField("stringdv", SortField.Type.STRING, reverse);
+        sf.setUseIndexValues(true);
+      } else {
+        sf = new SortField("string", SortField.Type.STRING, reverse);
+      }
+      final Sort sort = new Sort(sf);
+      final int hitCount = _TestUtil.nextInt(random, 1, r.maxDoc() + 20);
+      final RandomFilter f = new RandomFilter(random, random.nextFloat(), docValues);
+      if (random.nextBoolean()) {
+        hits = s.search(new ConstantScoreQuery(f),
+                        hitCount,
+                        sort);
+      } else {
+        hits = s.search(new MatchAllDocsQuery(),
+                        f,
+                        hitCount,
+                        sort);
+      }
+
+      if (VERBOSE) {
+        System.out.println("\nTEST: iter=" + iter + " " + hits.totalHits + " hits; topN=" + hitCount + "; reverse=" + reverse);
+      }
+
+      // Compute expected results:
+      Collections.sort(f.matchValues);
+      if (reverse) {
+        Collections.reverse(f.matchValues);
+      }
+      final List<BytesRef> expected = f.matchValues;
+      if (VERBOSE) {
+        System.out.println("  expected:");
+        for(int idx=0;idx<expected.size();idx++) {
+          System.out.println("    " + idx + ": " + expected.get(idx).utf8ToString());
+          if (idx == hitCount-1) {
+            break;
+          }
+        }
+      }
+      
+      if (VERBOSE) {
+        System.out.println("  actual:");
+        for(int hitIDX=0;hitIDX<hits.scoreDocs.length;hitIDX++) {
+          final FieldDoc fd = (FieldDoc) hits.scoreDocs[hitIDX];
+          System.out.println("    " + hitIDX + ": " + ((BytesRef) fd.fields[0]).utf8ToString());
+        }
+      }
+      for(int hitIDX=0;hitIDX<hits.scoreDocs.length;hitIDX++) {
+        final FieldDoc fd = (FieldDoc) hits.scoreDocs[hitIDX];
+        assertEquals(expected.get(hitIDX), (BytesRef) fd.fields[0]);
+      }
+    }
+
+    r.close();
+    dir.close();
+  }
 }
Index: lucene/core/src/test/org/apache/lucene/index/TestDocValuesIndexing.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/index/TestDocValuesIndexing.java	(revision 1293879)
+++ lucene/core/src/test/org/apache/lucene/index/TestDocValuesIndexing.java	(working copy)
@@ -792,7 +792,7 @@
         hash.get(sort[i], expected);
         asSortedSource.getByOrd(i, actual);
         assertEquals(expected.utf8ToString(), actual.utf8ToString());
-        int ord = asSortedSource.getByValue(expected, actual);
+        int ord = asSortedSource.getOrdByValue(expected, actual);
         assertEquals(i, ord);
       }
       AtomicReader slowR = SlowCompositeReaderWrapper.wrap(reader);
Index: lucene/core/src/java/org/apache/lucene/codecs/lucene40/values/VarSortedBytesImpl.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/codecs/lucene40/values/VarSortedBytesImpl.java	(revision 1293879)
+++ lucene/core/src/java/org/apache/lucene/codecs/lucene40/values/VarSortedBytesImpl.java	(working copy)
@@ -63,6 +63,7 @@
       this.comp = comp;
       size = 0;
     }
+
     @Override
     public void merge(MergeState mergeState, DocValues[] docValues)
         throws IOException {
Index: lucene/core/src/java/org/apache/lucene/search/FieldComparator.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/FieldComparator.java	(revision 1293879)
+++ lucene/core/src/java/org/apache/lucene/search/FieldComparator.java	(working copy)
@@ -1055,32 +1055,17 @@
       @Override
       public int compareBottom(int doc) {
         assert bottomSlot != -1;
+        final int docOrd = (readerOrds[doc]&0xFF);
         if (bottomSameReader) {
           // ord is precisely comparable, even in the equal case
-          return bottomOrd - (readerOrds[doc]&0xFF);
+          return bottomOrd - docOrd;
+        } else if (bottomOrd >= docOrd) {
+          // the equals case always means bottom is > doc
+          // (because we set bottomOrd to the lower bound in
+          // setBottom):
+          return 1;
         } else {
-          // ord is only approx comparable: if they are not
-          // equal, we can use that; if they are equal, we
-          // must fallback to compare by value
-          final int order = readerOrds[doc]&0xFF;
-          final int cmp = bottomOrd - order;
-          if (cmp != 0) {
-            return cmp;
-          }
-
-          if (bottomValue == null) {
-            if (order == 0) {
-              // unset
-              return 0;
-            }
-            // bottom wins
-            return -1;
-          } else if (order == 0) {
-            // doc wins
-            return 1;
-          }
-          termsIndex.lookup(order, tempBR);
-          return bottomValue.compareTo(tempBR);
+          return -1;
         }
       }
 
@@ -1116,32 +1101,17 @@
       @Override
       public int compareBottom(int doc) {
         assert bottomSlot != -1;
+        final int docOrd = (readerOrds[doc]&0xFFFF);
         if (bottomSameReader) {
           // ord is precisely comparable, even in the equal case
-          return bottomOrd - (readerOrds[doc]&0xFFFF);
+          return bottomOrd - docOrd;
+        } else if (bottomOrd >= docOrd) {
+          // the equals case always means bottom is > doc
+          // (because we set bottomOrd to the lower bound in
+          // setBottom):
+          return 1;
         } else {
-          // ord is only approx comparable: if they are not
-          // equal, we can use that; if they are equal, we
-          // must fallback to compare by value
-          final int order = readerOrds[doc]&0xFFFF;
-          final int cmp = bottomOrd - order;
-          if (cmp != 0) {
-            return cmp;
-          }
-
-          if (bottomValue == null) {
-            if (order == 0) {
-              // unset
-              return 0;
-            }
-            // bottom wins
-            return -1;
-          } else if (order == 0) {
-            // doc wins
-            return 1;
-          }
-          termsIndex.lookup(order, tempBR);
-          return bottomValue.compareTo(tempBR);
+          return -1;
         }
       }
 
@@ -1177,32 +1147,17 @@
       @Override
       public int compareBottom(int doc) {
         assert bottomSlot != -1;
+        final int docOrd = readerOrds[doc];
         if (bottomSameReader) {
           // ord is precisely comparable, even in the equal case
-          return bottomOrd - readerOrds[doc];
+          return bottomOrd - docOrd;
+        } else if (bottomOrd >= docOrd) {
+          // the equals case always means bottom is > doc
+          // (because we set bottomOrd to the lower bound in
+          // setBottom):
+          return 1;
         } else {
-          // ord is only approx comparable: if they are not
-          // equal, we can use that; if they are equal, we
-          // must fallback to compare by value
-          final int order = readerOrds[doc];
-          final int cmp = bottomOrd - order;
-          if (cmp != 0) {
-            return cmp;
-          }
-
-          if (bottomValue == null) {
-            if (order == 0) {
-              // unset
-              return 0;
-            }
-            // bottom wins
-            return -1;
-          } else if (order == 0) {
-            // doc wins
-            return 1;
-          }
-          termsIndex.lookup(order, tempBR);
-          return bottomValue.compareTo(tempBR);
+          return -1;
         }
       }
 
@@ -1239,32 +1194,17 @@
       @Override
       public int compareBottom(int doc) {
         assert bottomSlot != -1;
+        final int docOrd = (int) readerOrds.get(doc);
         if (bottomSameReader) {
           // ord is precisely comparable, even in the equal case
-          return bottomOrd - (int) readerOrds.get(doc);
+          return bottomOrd - docOrd;
+        } else if (bottomOrd >= docOrd) {
+          // the equals case always means bottom is > doc
+          // (because we set bottomOrd to the lower bound in
+          // setBottom):
+          return 1;
         } else {
-          // ord is only approx comparable: if they are not
-          // equal, we can use that; if they are equal, we
-          // must fallback to compare by value
-          final int order = (int) readerOrds.get(doc);
-          final int cmp = bottomOrd - order;
-          if (cmp != 0) {
-            return cmp;
-          }
-
-          if (bottomValue == null) {
-            if (order == 0) {
-              // unset
-              return 0;
-            }
-            // bottom wins
-            return -1;
-          } else if (order == 0) {
-            // doc wins
-            return 1;
-          }
-          termsIndex.lookup(order, tempBR);
-          return bottomValue.compareTo(tempBR);
+          return -1;
         }
       }
 
@@ -1499,21 +1439,17 @@
       @Override
       public int compareBottom(int doc) {
         assert bottomSlot != -1;
+        final int docOrd = readerOrds[doc]&0xFF;
         if (bottomSameReader) {
           // ord is precisely comparable, even in the equal case
-          return bottomOrd - (readerOrds[doc]&0xFF);
+          return bottomOrd - docOrd;
+        } else if (bottomOrd >= docOrd) {
+          // the equals case always means bottom is > doc
+          // (because we set bottomOrd to the lower bound in
+          // setBottom):
+          return 1;
         } else {
-          // ord is only approx comparable: if they are not
-          // equal, we can use that; if they are equal, we
-          // must fallback to compare by value
-          final int order = readerOrds[doc]&0xFF;
-          final int cmp = bottomOrd - order;
-          if (cmp != 0) {
-            return cmp;
-          }
-
-          termsIndex.getByOrd(order, tempBR);
-          return comp.compare(bottomValue, tempBR);
+          return -1;
         }
       }
 
@@ -1544,21 +1480,17 @@
       @Override
       public int compareBottom(int doc) {
         assert bottomSlot != -1;
+        final int docOrd = readerOrds[doc]&0xFFFF;
         if (bottomSameReader) {
           // ord is precisely comparable, even in the equal case
-          return bottomOrd - (readerOrds[doc]&0xFFFF);
+          return bottomOrd - docOrd;
+        } else if (bottomOrd >= docOrd) {
+          // the equals case always means bottom is > doc
+          // (because we set bottomOrd to the lower bound in
+          // setBottom):
+          return 1;
         } else {
-          // ord is only approx comparable: if they are not
-          // equal, we can use that; if they are equal, we
-          // must fallback to compare by value
-          final int order = readerOrds[doc]&0xFFFF;
-          final int cmp = bottomOrd - order;
-          if (cmp != 0) {
-            return cmp;
-          }
-
-          termsIndex.getByOrd(order, tempBR);
-          return comp.compare(bottomValue, tempBR);
+          return -1;
         }
       }
 
@@ -1589,20 +1521,17 @@
       @Override
       public int compareBottom(int doc) {
         assert bottomSlot != -1;
+        final int docOrd = readerOrds[doc];
         if (bottomSameReader) {
           // ord is precisely comparable, even in the equal case
-          return bottomOrd - readerOrds[doc];
+          return bottomOrd - docOrd;
+        } else if (bottomOrd >= docOrd) {
+          // the equals case always means bottom is > doc
+          // (because we set bottomOrd to the lower bound in
+          // setBottom):
+          return 1;
         } else {
-          // ord is only approx comparable: if they are not
-          // equal, we can use that; if they are equal, we
-          // must fallback to compare by value
-          final int order = readerOrds[doc];
-          final int cmp = bottomOrd - order;
-          if (cmp != 0) {
-            return cmp;
-          }
-          termsIndex.getByOrd(order, tempBR);
-          return comp.compare(bottomValue, tempBR);
+          return -1;
         }
       }
 
@@ -1632,20 +1561,17 @@
       @Override
       public int compareBottom(int doc) {
         assert bottomSlot != -1;
+        final int docOrd = (int) readerOrds.get(doc);
         if (bottomSameReader) {
           // ord is precisely comparable, even in the equal case
-          return bottomOrd - (int) readerOrds.get(doc);
+          return bottomOrd - docOrd;
+        } else if (bottomOrd >= docOrd) {
+          // the equals case always means bottom is > doc
+          // (because we set bottomOrd to the lower bound in
+          // setBottom):
+          return 1;
         } else {
-          // ord is only approx comparable: if they are not
-          // equal, we can use that; if they are equal, we
-          // must fallback to compare by value
-          final int order = (int) readerOrds.get(doc);
-          final int cmp = bottomOrd - order;
-          if (cmp != 0) {
-            return cmp;
-          }
-          termsIndex.getByOrd(order, tempBR);
-          return comp.compare(bottomValue, tempBR);
+          return -1;
         }
       }
 
@@ -1672,21 +1598,17 @@
 
       @Override
       public int compareBottom(int doc) {
-        assert bottomSlot != -1;
+        final int docOrd = termsIndex.ord(doc);
         if (bottomSameReader) {
           // ord is precisely comparable, even in the equal case
-          return bottomOrd - termsIndex.ord(doc);
+          return bottomOrd - docOrd;
+        } else if (bottomOrd >= docOrd) {
+          // the equals case always means bottom is > doc
+          // (because we set bottomOrd to the lower bound in
+          // setBottom):
+          return 1;
         } else {
-          // ord is only approx comparable: if they are not
-          // equal, we can use that; if they are equal, we
-          // must fallback to compare by value
-          final int order = termsIndex.ord(doc);
-          final int cmp = bottomOrd - order;
-          if (cmp != 0) {
-            return cmp;
-          }
-          termsIndex.getByOrd(order, tempBR);
-          return comp.compare(bottomValue, tempBR);
+          return -1;
         }
       }
 
@@ -1775,7 +1697,7 @@
           bottomSameReader = true;
           readerGen[bottomSlot] = currentReaderGen;
         } else {
-          final int index = termsIndex.getByValue(bottomValue, tempBR);
+          final int index = termsIndex.getOrdByValue(bottomValue, tempBR);
           if (index < 0) {
             bottomOrd = -index - 2;
             bottomSameReader = false;
Index: lucene/core/src/java/org/apache/lucene/search/TopFieldCollector.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/TopFieldCollector.java	(revision 1293879)
+++ lucene/core/src/java/org/apache/lucene/search/TopFieldCollector.java	(working copy)
@@ -70,7 +70,7 @@
       if (queueFull) {
         if ((reverseMul * comparator.compareBottom(doc)) <= 0) {
           // since docs are visited in doc Id order, if compare is 0, it means
-          // this document is largest than anything else in the queue, and
+          // this document is larger than anything else in the queue, and
           // therefore not competitive.
           return;
         }
Index: lucene/core/src/java/org/apache/lucene/index/SortedBytesMergeUtils.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/index/SortedBytesMergeUtils.java	(revision 1293879)
+++ lucene/core/src/java/org/apache/lucene/index/SortedBytesMergeUtils.java	(working copy)
@@ -81,7 +81,7 @@
     }
   }
 
-  public static List<SortedSourceSlice> buildSlices(int[] docBases ,int[][] docMaps,
+  public static List<SortedSourceSlice> buildSlices(int[] docBases, int[][] docMaps,
       DocValues[] docValues, MergeContext ctx) throws IOException {
     final List<SortedSourceSlice> slices = new ArrayList<SortedSourceSlice>();
     for (int i = 0; i < docValues.length; i++) {
@@ -111,7 +111,7 @@
    * mapping in docIDToRelativeOrd. After the merge SortedSourceSlice#ordMapping
    * contains the new global ordinals for the relative index.
    */
-  private static void createOrdMapping(int[] docBases ,int[][] docMaps,
+  private static void createOrdMapping(int[] docBases, int[][] docMaps,
       SortedSourceSlice currentSlice) {
     final int readerIdx = currentSlice.readerIdx;
     final int[] currentDocMap = docMaps[readerIdx];
Index: lucene/core/src/java/org/apache/lucene/index/DocFieldProcessor.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/index/DocFieldProcessor.java	(revision 1293879)
+++ lucene/core/src/java/org/apache/lucene/index/DocFieldProcessor.java	(working copy)
@@ -337,6 +337,9 @@
     if (perDocConsumer == null) {
       PerDocWriteState perDocWriteState = docState.docWriter.newPerDocWriteState("");
       perDocConsumer = docState.docWriter.codec.docValuesFormat().docsConsumer(perDocWriteState);
+      if (perDocConsumer == null) {
+        throw new IllegalStateException("codec=" +  docState.docWriter.codec + " does not support docValues: from docValuesFormat().docsConsumer(...) returned null; field=" + fieldInfo.name);
+      }
     }
     DocValuesConsumer docValuesConsumer = perDocConsumer.addValuesField(valueType, fieldInfo);
     fieldInfo.setDocValuesType(valueType, false);
Index: lucene/core/src/java/org/apache/lucene/index/DocValues.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/index/DocValues.java	(revision 1293879)
+++ lucene/core/src/java/org/apache/lucene/index/DocValues.java	(working copy)
@@ -148,6 +148,7 @@
     protected Source(Type type) {
       this.type = type;
     }
+
     /**
      * Returns a <tt>long</tt> for the given document id or throws an
      * {@link UnsupportedOperationException} if this source doesn't support
@@ -239,9 +240,10 @@
     public BytesRef getBytes(int docID, BytesRef bytesRef) {
       final int ord = ord(docID);
       if (ord < 0) {
+        // Negative ord means doc was missing?
         bytesRef.length = 0;
       } else {
-        getByOrd(ord , bytesRef);
+        getByOrd(ord, bytesRef);
       }
       return bytesRef;
     }
@@ -253,7 +255,7 @@
     public abstract int ord(int docID);
 
     /** Returns value for specified ord. */
-    public abstract BytesRef getByOrd(int ord, BytesRef bytesRef);
+    public abstract BytesRef getByOrd(int ord, BytesRef result);
 
     /** Return true if it's safe to call {@link
      *  #getDocToOrd}. */
@@ -274,7 +276,7 @@
     }
 
     /**
-     * Performs a lookup by value.
+     * Lookup ord by value.
      * 
      * @param value
      *          the value to look up
@@ -283,11 +285,11 @@
      *          values to the given value. Must not be <code>null</code>
      * @return the given values ordinal if found or otherwise
      *         <code>(-(ord)-1)</code>, defined as the ordinal of the first
-     *         element that is greater than the given value. This guarantees
-     *         that the return value will always be &gt;= 0 if the given value
-     *         is found.
+     *         element that is greater than the given value (the insertion
+     *         point). This guarantees that the return value will always be
+     *         &gt;= 0 if the given value is found.
      */
-    public int getByValue(BytesRef value, BytesRef spare) {
+    public int getOrdByValue(BytesRef value, BytesRef spare) {
       return binarySearch(value, spare, 0, getValueCount() - 1);
     }    
 
@@ -405,7 +407,7 @@
       }
 
       @Override
-      public int getByValue(BytesRef value, BytesRef spare) {
+      public int getOrdByValue(BytesRef value, BytesRef spare) {
         if (value.length == 0) {
           return 0;
         } else {
@@ -414,7 +416,7 @@
       }
 
       @Override
-        public int getValueCount() {
+      public int getValueCount() {
         return 1;
       }
     };
Index: lucene/test-framework/src/java/org/apache/lucene/util/_TestUtil.java
===================================================================
--- lucene/test-framework/src/java/org/apache/lucene/util/_TestUtil.java	(revision 1293879)
+++ lucene/test-framework/src/java/org/apache/lucene/util/_TestUtil.java	(working copy)
@@ -191,8 +191,8 @@
     return start + r.nextInt(end-start+1);
   }
 
-  public static String randomSimpleString(Random r) {
-    final int end = r.nextInt(10);
+  public static String randomSimpleString(Random r, int maxLength) {
+    final int end = r.nextInt(maxLength);
     if (end == 0) {
       // allow 0 length
       return "";
@@ -204,6 +204,10 @@
     return new String(buffer, 0, end);
   }
 
+  public static String randomSimpleString(Random r) {
+    return randomSimpleString(r, 10);
+  }
+
   /** Returns random string, including full unicode range. */
   public static String randomUnicodeString(Random r) {
     return randomUnicodeString(r, 20);