docs/attachments/LUCENE-6218/LUCENE-6218.patch

Index: lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsReader.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsReader.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/codecs/lucene50/Lucene50PostingsReader.java	(working copy)
@@ -320,7 +320,7 @@
 
       doc = -1;
       this.needsFreq = (flags & DocsEnum.FLAG_FREQS) != 0;
-      if (!indexHasFreq) {
+      if (indexHasFreq == false || needsFreq == false) {
         Arrays.fill(freqBuffer, 1);
       }
       accum = 0;
Index: lucene/core/src/java/org/apache/lucene/search/BooleanQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/BooleanQuery.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/BooleanQuery.java	(working copy)
@@ -242,7 +242,7 @@
       for (Iterator<Weight> wIter = weights.iterator(); wIter.hasNext();) {
         Weight w = wIter.next();
         BooleanClause c = cIter.next();
-        if (w.scorer(context, context.reader().getLiveDocs()) == null) {
+        if (w.scorer(context, context.reader().getLiveDocs(), true) == null) {
           if (c.isRequired()) {
             fail = true;
             Explanation r = new Explanation(0.0f, "no match on required clause (" + c.getQuery().toString() + ")");
@@ -307,12 +307,12 @@
     /** Try to build a boolean scorer for this weight. Returns null if {@link BooleanScorer}
      *  cannot be used. */
     // pkg-private for forcing use of BooleanScorer in tests
-    BooleanScorer booleanScorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    BooleanScorer booleanScorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       List<BulkScorer> optional = new ArrayList<BulkScorer>();
       Iterator<BooleanClause> cIter = clauses.iterator();
       for (Weight w  : weights) {
         BooleanClause c =  cIter.next();
-        BulkScorer subScorer = w.bulkScorer(context, acceptDocs);
+        BulkScorer subScorer = w.bulkScorer(context, acceptDocs, needsScores);
         if (subScorer == null) {
           if (c.isRequired()) {
             return null;
@@ -342,8 +342,8 @@
     }
 
     @Override
-    public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
-      final BooleanScorer bulkScorer = booleanScorer(context, acceptDocs);
+    public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
+      final BooleanScorer bulkScorer = booleanScorer(context, acceptDocs, needsScores);
       if (bulkScorer != null) { // BooleanScorer is applicable
         // TODO: what is the right heuristic here?
         final long costThreshold;
@@ -366,12 +366,11 @@
           return bulkScorer;
         }
       }
-      return super.bulkScorer(context, acceptDocs);
+      return super.bulkScorer(context, acceptDocs, needsScores);
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs)
-        throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       // initially the user provided value,
       // but if minNrShouldMatch == optional.size(),
       // we will optimize and move these to required, making this 0
@@ -383,7 +382,7 @@
       Iterator<BooleanClause> cIter = clauses.iterator();
       for (Weight w  : weights) {
         BooleanClause c =  cIter.next();
-        Scorer subScorer = w.scorer(context, acceptDocs);
+        Scorer subScorer = w.scorer(context, acceptDocs, needsScores && c.isProhibited() == false);
         if (subScorer == null) {
           if (c.isRequired()) {
             return null;
@@ -416,6 +415,11 @@
         return null;
       }
       
+      // we don't need scores, so if we have required clauses, drop optional clauses completely
+      if (!needsScores && minShouldMatch == 0 && required.size() > 0) {
+        optional.clear();
+      }
+      
       // three cases: conjunction, disjunction, or mix
       
       // pure conjunction
Index: lucene/core/src/java/org/apache/lucene/search/CachingCollector.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/CachingCollector.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/CachingCollector.java	(working copy)
@@ -297,6 +297,11 @@
       @Override
       public void collect(int doc) {}
 
+      @Override
+      public boolean needsScores() {
+        return true;
+      }
+
     };
     return create(other, cacheScores, maxRAMMB);
   }
Index: lucene/core/src/java/org/apache/lucene/search/Collector.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/Collector.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/Collector.java	(working copy)
@@ -73,4 +73,10 @@
    */
   LeafCollector getLeafCollector(LeafReaderContext context) throws IOException;
 
+  /**
+   * Indicates if document scores are needed by this collector.
+   * 
+   * @return {@code true} if scores are needed.
+   */
+  boolean needsScores();
 }
Index: lucene/core/src/java/org/apache/lucene/search/ConstantScoreQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/ConstantScoreQuery.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/ConstantScoreQuery.java	(working copy)
@@ -134,14 +134,14 @@
     }
 
     @Override
-    public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       final DocIdSetIterator disi;
       if (filter != null) {
         assert query == null;
-        return super.bulkScorer(context, acceptDocs);
+        return super.bulkScorer(context, acceptDocs, needsScores);
       } else {
         assert query != null && innerWeight != null;
-        BulkScorer bulkScorer = innerWeight.bulkScorer(context, acceptDocs);
+        BulkScorer bulkScorer = innerWeight.bulkScorer(context, acceptDocs, false);
         if (bulkScorer == null) {
           return null;
         }
@@ -150,7 +150,7 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       final DocIdSetIterator disi;
       if (filter != null) {
         assert query == null;
@@ -161,7 +161,7 @@
         disi = dis.iterator();
       } else {
         assert query != null && innerWeight != null;
-        disi = innerWeight.scorer(context, acceptDocs);
+        disi = innerWeight.scorer(context, acceptDocs, false);
       }
 
       if (disi == null) {
@@ -172,7 +172,7 @@
 
     @Override
     public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-      final Scorer cs = scorer(context, context.reader().getLiveDocs());
+      final Scorer cs = scorer(context, context.reader().getLiveDocs(), true);
       final boolean exists = (cs != null && cs.advance(doc) == doc);
 
       final ComplexExplanation result = new ComplexExplanation();
Index: lucene/core/src/java/org/apache/lucene/search/DisjunctionMaxQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/DisjunctionMaxQuery.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/DisjunctionMaxQuery.java	(working copy)
@@ -153,11 +153,11 @@
 
     /** Create the scorer used to score our associated DisjunctionMaxQuery */
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       List<Scorer> scorers = new ArrayList<>();
       for (Weight w : weights) {
         // we will advance() subscorers
-        Scorer subScorer = w.scorer(context, acceptDocs);
+        Scorer subScorer = w.scorer(context, acceptDocs, needsScores);
         if (subScorer != null) {
           scorers.add(subScorer);
         }
Index: lucene/core/src/java/org/apache/lucene/search/ExactPhraseScorer.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/ExactPhraseScorer.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/ExactPhraseScorer.java	(working copy)
@@ -55,11 +55,13 @@
   private int freq;
 
   private final Similarity.SimScorer docScorer;
+  private final boolean needsScores;
   
   ExactPhraseScorer(Weight weight, PhraseQuery.PostingsAndFreq[] postings,
-                    Similarity.SimScorer docScorer) throws IOException {
+                    Similarity.SimScorer docScorer, boolean needsScores) throws IOException {
     super(weight);
     this.docScorer = docScorer;
+    this.needsScores = needsScores;
 
     chunkStates = new ChunkState[postings.length];
 
@@ -233,6 +235,9 @@
             final int posIndex = cs.pos - chunkStart;
             if (posIndex >= 0 && gens[posIndex] == gen && counts[posIndex] == endMinus1) {
               freq++;
+              if (!needsScores) {
+                return freq; // we determined there was a match.
+              }
             }
           }
 
Index: lucene/core/src/java/org/apache/lucene/search/FilterCollector.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/FilterCollector.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/FilterCollector.java	(working copy)
@@ -44,5 +44,9 @@
   public String toString() {
     return getClass().getSimpleName() + "(" + in + ")";
   }
-  
+
+  @Override
+  public boolean needsScores() {
+    return in.needsScores();
+  }
 }
Index: lucene/core/src/java/org/apache/lucene/search/FilteredQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/FilteredQuery.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/FilteredQuery.java	(working copy)
@@ -119,7 +119,7 @@
 
       // return a filtering scorer
       @Override
-      public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+      public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
         assert filter != null;
 
         DocIdSet filterDocIdSet = filter.getDocIdSet(context, acceptDocs);
@@ -128,12 +128,12 @@
           return null;
         }
 
-        return strategy.filteredScorer(context, weight, filterDocIdSet);
+        return strategy.filteredScorer(context, weight, filterDocIdSet, needsScores);
       }
 
       // return a filtering top scorer
       @Override
-      public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+      public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
         assert filter != null;
 
         DocIdSet filterDocIdSet = filter.getDocIdSet(context, acceptDocs);
@@ -142,7 +142,7 @@
           return null;
         }
 
-        return strategy.filteredBulkScorer(context, weight, filterDocIdSet);
+        return strategy.filteredBulkScorer(context, weight, filterDocIdSet, needsScores);
       }
     };
   }
@@ -465,7 +465,7 @@
      * @throws IOException if an {@link IOException} occurs
      */
     public abstract Scorer filteredScorer(LeafReaderContext context,
-        Weight weight, DocIdSet docIdSet) throws IOException;
+        Weight weight, DocIdSet docIdSet, boolean needsScores) throws IOException;
 
     /**
      * Returns a filtered {@link BulkScorer} based on this
@@ -480,8 +480,8 @@
      * @return a filtered top scorer
      */
     public BulkScorer filteredBulkScorer(LeafReaderContext context,
-        Weight weight, DocIdSet docIdSet) throws IOException {
-      Scorer scorer = filteredScorer(context, weight, docIdSet);
+        Weight weight, DocIdSet docIdSet, boolean needsScores) throws IOException {
+      Scorer scorer = filteredScorer(context, weight, docIdSet, needsScores);
       if (scorer == null) {
         return null;
       }
@@ -502,7 +502,7 @@
   public static class RandomAccessFilterStrategy extends FilterStrategy {
 
     @Override
-    public Scorer filteredScorer(LeafReaderContext context, Weight weight, DocIdSet docIdSet) throws IOException {
+    public Scorer filteredScorer(LeafReaderContext context, Weight weight, DocIdSet docIdSet, boolean needsScores) throws IOException {
       final DocIdSetIterator filterIter = docIdSet.iterator();
       if (filterIter == null) {
         // this means the filter does not accept any documents.
@@ -514,11 +514,11 @@
       final boolean useRandomAccess = filterAcceptDocs != null && useRandomAccess(filterAcceptDocs, filterIter.cost());
       if (useRandomAccess) {
         // if we are using random access, we return the inner scorer, just with other acceptDocs
-        return weight.scorer(context, filterAcceptDocs);
+        return weight.scorer(context, filterAcceptDocs, needsScores);
       } else {
         // we are gonna advance() this scorer, so we set inorder=true/toplevel=false
         // we pass null as acceptDocs, as our filter has already respected acceptDocs, no need to do twice
-        final Scorer scorer = weight.scorer(context, null);
+        final Scorer scorer = weight.scorer(context, null, needsScores);
         return (scorer == null) ? null : new LeapFrogScorer(weight, filterIter, scorer, scorer);
       }
     }
@@ -551,7 +551,7 @@
 
     @Override
     public Scorer filteredScorer(LeafReaderContext context,
-        Weight weight, DocIdSet docIdSet) throws IOException {
+        Weight weight, DocIdSet docIdSet, boolean needsScores) throws IOException {
       final DocIdSetIterator filterIter = docIdSet.iterator();
       if (filterIter == null) {
         // this means the filter does not accept any documents.
@@ -558,7 +558,7 @@
         return null;
       }
       // we pass null as acceptDocs, as our filter has already respected acceptDocs, no need to do twice
-      final Scorer scorer = weight.scorer(context, null);
+      final Scorer scorer = weight.scorer(context, null, needsScores);
       if (scorer == null) {
         return null;
       }
@@ -587,15 +587,14 @@
   private static final class QueryFirstFilterStrategy extends FilterStrategy {
     @Override
     public Scorer filteredScorer(final LeafReaderContext context,
-        Weight weight,
-        DocIdSet docIdSet) throws IOException {
+        Weight weight, DocIdSet docIdSet, boolean needsScores) throws IOException {
       Bits filterAcceptDocs = docIdSet.bits();
       if (filterAcceptDocs == null) {
         // Filter does not provide random-access Bits; we
         // must fallback to leapfrog:
-        return LEAP_FROG_QUERY_FIRST_STRATEGY.filteredScorer(context, weight, docIdSet);
+        return LEAP_FROG_QUERY_FIRST_STRATEGY.filteredScorer(context, weight, docIdSet, needsScores);
       }
-      final Scorer scorer = weight.scorer(context, null);
+      final Scorer scorer = weight.scorer(context, null, needsScores);
       return scorer == null ? null : new QueryFirstScorer(weight,
           filterAcceptDocs, scorer);
     }
@@ -602,15 +601,14 @@
 
     @Override
     public BulkScorer filteredBulkScorer(final LeafReaderContext context,
-        Weight weight,
-        DocIdSet docIdSet) throws IOException {
+        Weight weight, DocIdSet docIdSet, boolean needsScores) throws IOException {
       Bits filterAcceptDocs = docIdSet.bits();
       if (filterAcceptDocs == null) {
         // Filter does not provide random-access Bits; we
         // must fallback to leapfrog:
-        return LEAP_FROG_QUERY_FIRST_STRATEGY.filteredBulkScorer(context, weight, docIdSet);
+        return LEAP_FROG_QUERY_FIRST_STRATEGY.filteredBulkScorer(context, weight, docIdSet, needsScores);
       }
-      final Scorer scorer = weight.scorer(context, null);
+      final Scorer scorer = weight.scorer(context, null, needsScores);
       return scorer == null ? null : new QueryFirstBulkScorer(scorer, filterAcceptDocs);
     }
   }
Index: lucene/core/src/java/org/apache/lucene/search/IndexSearcher.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/IndexSearcher.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/IndexSearcher.java	(working copy)
@@ -586,7 +586,7 @@
         // continue with the following leaf
         continue;
       }
-      BulkScorer scorer = weight.bulkScorer(ctx, ctx.reader().getLiveDocs());
+      BulkScorer scorer = weight.bulkScorer(ctx, ctx.reader().getLiveDocs(), collector.needsScores());
       if (scorer != null) {
         try {
           scorer.score(leafCollector);
Index: lucene/core/src/java/org/apache/lucene/search/MatchAllDocsQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/MatchAllDocsQuery.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/MatchAllDocsQuery.java	(working copy)
@@ -114,7 +114,7 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       return new MatchAllScorer(context.reader(), acceptDocs, this, queryWeight);
     }
 
Index: lucene/core/src/java/org/apache/lucene/search/MultiCollector.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/MultiCollector.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/MultiCollector.java	(working copy)
@@ -93,6 +93,16 @@
   }
 
   @Override
+  public boolean needsScores() {
+    for (Collector collector : collectors) {
+      if (collector.needsScores()) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  @Override
   public LeafCollector getLeafCollector(LeafReaderContext context) throws IOException {
     final LeafCollector[] leafCollectors = new LeafCollector[collectors.length];
     for (int i = 0; i < collectors.length; ++i) {
Index: lucene/core/src/java/org/apache/lucene/search/MultiPhraseQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/MultiPhraseQuery.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/MultiPhraseQuery.java	(working copy)
@@ -179,7 +179,7 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       assert !termArrays.isEmpty();
       final LeafReader reader = context.reader();
       final Bits liveDocs = acceptDocs;
@@ -249,15 +249,15 @@
       }
 
       if (slop == 0) {
-        return new ExactPhraseScorer(this, postingsFreqs, similarity.simScorer(stats, context));
+        return new ExactPhraseScorer(this, postingsFreqs, similarity.simScorer(stats, context), needsScores);
       } else {
-        return new SloppyPhraseScorer(this, postingsFreqs, slop, similarity.simScorer(stats, context));
+        return new SloppyPhraseScorer(this, postingsFreqs, slop, similarity.simScorer(stats, context), needsScores);
       }
     }
 
     @Override
     public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-      Scorer scorer = scorer(context, context.reader().getLiveDocs());
+      Scorer scorer = scorer(context, context.reader().getLiveDocs(), true);
       if (scorer != null) {
         int newDoc = scorer.advance(doc);
         if (newDoc == doc) {
Index: lucene/core/src/java/org/apache/lucene/search/PhraseQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/PhraseQuery.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/PhraseQuery.java	(working copy)
@@ -245,7 +245,7 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       assert !terms.isEmpty();
       final LeafReader reader = context.reader();
       final Bits liveDocs = acceptDocs;
@@ -285,9 +285,9 @@
       }
 
       if (slop == 0) {  // optimize exact case
-        return new ExactPhraseScorer(this, postingsFreqs, similarity.simScorer(stats, context));
+        return new ExactPhraseScorer(this, postingsFreqs, similarity.simScorer(stats, context), needsScores);
       } else {
-        return new SloppyPhraseScorer(this, postingsFreqs, slop, similarity.simScorer(stats, context));
+        return new SloppyPhraseScorer(this, postingsFreqs, slop, similarity.simScorer(stats, context), needsScores);
       }
     }
     
@@ -298,7 +298,7 @@
 
     @Override
     public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-      Scorer scorer = scorer(context, context.reader().getLiveDocs());
+      Scorer scorer = scorer(context, context.reader().getLiveDocs(), true);
       if (scorer != null) {
         int newDoc = scorer.advance(doc);
         if (newDoc == doc) {
Index: lucene/core/src/java/org/apache/lucene/search/QueryRescorer.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/QueryRescorer.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/QueryRescorer.java	(working copy)
@@ -82,7 +82,7 @@
       if (readerContext != null) {
         // We advanced to another segment:
         docBase = readerContext.docBase;
-        scorer = weight.scorer(readerContext, null);
+        scorer = weight.scorer(readerContext, null, true);
       }
 
       if(scorer != null) {
Index: lucene/core/src/java/org/apache/lucene/search/QueryWrapperFilter.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/QueryWrapperFilter.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/QueryWrapperFilter.java	(working copy)
@@ -56,7 +56,7 @@
     return new DocIdSet() {
       @Override
       public DocIdSetIterator iterator() throws IOException {
-        return weight.scorer(privateContext, acceptDocs);
+        return weight.scorer(privateContext, acceptDocs, false);
       }
 
       @Override
Index: lucene/core/src/java/org/apache/lucene/search/SloppyPhraseScorer.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/SloppyPhraseScorer.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/SloppyPhraseScorer.java	(working copy)
@@ -50,11 +50,13 @@
   
   private int numMatches;
   private final long cost;
+  final boolean needsScores;
   
   SloppyPhraseScorer(Weight weight, PhraseQuery.PostingsAndFreq[] postings,
-      int slop, Similarity.SimScorer docScorer) {
+      int slop, Similarity.SimScorer docScorer, boolean needsScores) {
     super(weight);
     this.docScorer = docScorer;
+    this.needsScores = needsScores;
     this.slop = slop;
     this.numPostings = postings==null ? 0 : postings.length;
     pq = new PhraseQueue(postings.length);
@@ -114,6 +116,9 @@
         if (matchLength <= slop) {
           freq += docScorer.computeSlopFactor(matchLength); // score match
           numMatches++;
+          if (!needsScores) {
+            return freq;
+          }
         }      
         pq.add(pp);
         pp = pq.pop();
Index: lucene/core/src/java/org/apache/lucene/search/TermQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/TermQuery.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/TermQuery.java	(working copy)
@@ -75,13 +75,13 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       assert termStates.topReaderContext == ReaderUtil.getTopLevelContext(context) : "The top-reader used to create Weight (" + termStates.topReaderContext + ") is not the same as the current reader's top-reader (" + ReaderUtil.getTopLevelContext(context);
       final TermsEnum termsEnum = getTermsEnum(context);
       if (termsEnum == null) {
         return null;
       }
-      DocsEnum docs = termsEnum.docs(acceptDocs, null);
+      DocsEnum docs = termsEnum.docs(acceptDocs, null, needsScores ? DocsEnum.FLAG_FREQS : DocsEnum.FLAG_NONE);
       assert docs != null;
       return new TermScorer(this, docs, similarity.simScorer(stats, context));
     }
@@ -110,7 +110,7 @@
     
     @Override
     public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-      Scorer scorer = scorer(context, context.reader().getLiveDocs());
+      Scorer scorer = scorer(context, context.reader().getLiveDocs(), true);
       if (scorer != null) {
         int newDoc = scorer.advance(doc);
         if (newDoc == doc) {
Index: lucene/core/src/java/org/apache/lucene/search/TimeLimitingCollector.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/TimeLimitingCollector.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/TimeLimitingCollector.java	(working copy)
@@ -157,6 +157,11 @@
     };
   }
   
+  @Override
+  public boolean needsScores() {
+    return collector.needsScores();
+  }
+
   /**
    * This is so the same timer can be used with a multi-phase search process such as grouping. 
    * We don't want to create a new TimeLimitingCollector for each phase because that would 
Index: lucene/core/src/java/org/apache/lucene/search/TopFieldCollector.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/TopFieldCollector.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/TopFieldCollector.java	(working copy)
@@ -129,8 +129,8 @@
 
     final FieldValueHitQueue<Entry> queue;
 
-    public NonScoringCollector(FieldValueHitQueue<Entry> queue, int numHits, boolean fillFields) {
-      super(queue, numHits, fillFields);
+    public NonScoringCollector(Sort sort, FieldValueHitQueue<Entry> queue, int numHits, boolean fillFields) {
+      super(queue, numHits, fillFields, sort.needsScores());
       this.queue = queue;
     }
 
@@ -216,8 +216,8 @@
 
     final FieldValueHitQueue<Entry> queue;
 
-    public ScoringNoMaxScoreCollector(FieldValueHitQueue<Entry> queue, int numHits, boolean fillFields) {
-      super(queue, numHits, fillFields);
+    public ScoringNoMaxScoreCollector(Sort sort, FieldValueHitQueue<Entry> queue, int numHits, boolean fillFields) {
+      super(queue, numHits, fillFields, true);
       this.queue = queue;
     }
 
@@ -315,8 +315,8 @@
 
     final FieldValueHitQueue<Entry> queue;
 
-    public ScoringMaxScoreCollector(FieldValueHitQueue<Entry> queue, int numHits, boolean fillFields) {
-      super(queue, numHits, fillFields);
+    public ScoringMaxScoreCollector(Sort sort, FieldValueHitQueue<Entry> queue, int numHits, boolean fillFields) {
+      super(queue, numHits, fillFields, true);
       this.queue = queue;
       maxScore = Float.MIN_NORMAL; // otherwise we would keep NaN
     }
@@ -414,9 +414,9 @@
     final boolean trackMaxScore;
     final FieldDoc after;
 
-    public PagingFieldCollector(FieldValueHitQueue<Entry> queue, FieldDoc after, int numHits, boolean fillFields,
+    public PagingFieldCollector(Sort sort, FieldValueHitQueue<Entry> queue, FieldDoc after, int numHits, boolean fillFields,
                                 boolean trackDocScores, boolean trackMaxScore) {
-      super(queue, numHits, fillFields);
+      super(queue, numHits, fillFields, trackDocScores || trackMaxScore || sort.needsScores());
       this.queue = queue;
       this.trackDocScores = trackDocScores;
       this.trackMaxScore = trackMaxScore;
@@ -520,6 +520,7 @@
   FieldValueHitQueue.Entry bottom = null;
   boolean queueFull;
   int docBase;
+  final boolean needsScores;
 
   // Declaring the constructor private prevents extending this class by anyone
   // else. Note that the class cannot be final since it's extended by the
@@ -526,12 +527,18 @@
   // internal versions. If someone will define a constructor with any other
   // visibility, then anyone will be able to extend the class, which is not what
   // we want.
-  private TopFieldCollector(PriorityQueue<Entry> pq, int numHits, boolean fillFields) {
+  private TopFieldCollector(PriorityQueue<Entry> pq, int numHits, boolean fillFields, boolean needsScores) {
     super(pq);
+    this.needsScores = needsScores;
     this.numHits = numHits;
     this.fillFields = fillFields;
   }
 
+  @Override
+  public boolean needsScores() {
+    return needsScores;
+  }
+
   /**
    * Creates a new {@link TopFieldCollector} from the given
    * arguments.
@@ -622,11 +629,11 @@
 
     if (after == null) {
       if (trackMaxScore) {
-        return new ScoringMaxScoreCollector(queue, numHits, fillFields);
+        return new ScoringMaxScoreCollector(sort, queue, numHits, fillFields);
       } else if (trackDocScores) {
-        return new ScoringNoMaxScoreCollector(queue, numHits, fillFields);
+        return new ScoringNoMaxScoreCollector(sort, queue, numHits, fillFields);
       } else {
-        return new NonScoringCollector(queue, numHits, fillFields);
+        return new NonScoringCollector(sort, queue, numHits, fillFields);
       }
     } else {
       if (after.fields == null) {
@@ -637,7 +644,7 @@
         throw new IllegalArgumentException("after.fields has " + after.fields.length + " values but sort has " + sort.getSort().length);
       }
 
-      return new PagingFieldCollector(queue, after, numHits, fillFields, trackDocScores, trackMaxScore);
+      return new PagingFieldCollector(sort, queue, after, numHits, fillFields, trackDocScores, trackMaxScore);
     }
   }
 
Index: lucene/core/src/java/org/apache/lucene/search/TopScoreDocCollector.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/TopScoreDocCollector.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/TopScoreDocCollector.java	(working copy)
@@ -207,4 +207,9 @@
 
     return new TopDocs(totalHits, results, maxScore);
   }
+
+  @Override
+  public boolean needsScores() {
+    return true;
+  }
 }
Index: lucene/core/src/java/org/apache/lucene/search/TotalHitCountCollector.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/TotalHitCountCollector.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/TotalHitCountCollector.java	(working copy)
@@ -34,4 +34,9 @@
   public void collect(int doc) {
     totalHits++;
   }
+
+  @Override
+  public boolean needsScores() {
+    return false;
+  }
 }
Index: lucene/core/src/java/org/apache/lucene/search/Weight.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/Weight.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/Weight.java	(working copy)
@@ -34,7 +34,7 @@
  * {@link org.apache.lucene.index.LeafReader} dependent state should reside in the {@link Scorer}.
  * <p>
  * Since {@link Weight} creates {@link Scorer} instances for a given
- * {@link org.apache.lucene.index.LeafReaderContext} ({@link #scorer(org.apache.lucene.index.LeafReaderContext, Bits)})
+ * {@link org.apache.lucene.index.LeafReaderContext} ({@link #scorer(org.apache.lucene.index.LeafReaderContext, Bits, boolean)})
  * callers must maintain the relationship between the searcher's top-level
  * {@link IndexReaderContext} and the context used to create a {@link Scorer}. 
  * <p>
@@ -49,7 +49,7 @@
  * <li>The query normalization factor is passed to {@link #normalize(float, float)}. At
  * this point the weighting is complete.
  * <li>A <code>Scorer</code> is constructed by
- * {@link #scorer(org.apache.lucene.index.LeafReaderContext, Bits)}.
+ * {@link #scorer(org.apache.lucene.index.LeafReaderContext, Bits, boolean)}.
  * </ol>
  * 
  * @since 2.9
@@ -87,11 +87,13 @@
    * @param acceptDocs
    *          Bits that represent the allowable docs to match (typically deleted docs
    *          but possibly filtering other documents)
+   * @param needsScores
+   *          True if document scores ({@link Scorer#score}) or match frequencies ({@link Scorer#freq}) are needed.
    *          
    * @return a {@link Scorer} which scores documents in/out-of order.
    * @throws IOException if there is a low-level I/O error
    */
-  public abstract Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException;
+  public abstract Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException;
 
   /**
    * Optional method, to return a {@link BulkScorer} to
@@ -106,14 +108,16 @@
    * @param acceptDocs
    *          Bits that represent the allowable docs to match (typically deleted docs
    *          but possibly filtering other documents)
+   * @param needsScores
+   *          True if document scores are needed.
    *
    * @return a {@link BulkScorer} which scores documents and
    * passes them to a collector.
    * @throws IOException if there is a low-level I/O error
    */
-  public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+  public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
 
-    Scorer scorer = scorer(context, acceptDocs);
+    Scorer scorer = scorer(context, acceptDocs, needsScores);
     if (scorer == null) {
       // No docs match
       return null;
Index: lucene/core/src/java/org/apache/lucene/search/package.html
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/package.html	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/package.html	(working copy)
@@ -436,15 +436,13 @@
                 that scores via a {@link org.apache.lucene.search.similarities.Similarity Similarity} will just defer to the Similarity's implementation:
                 {@link org.apache.lucene.search.similarities.Similarity.SimWeight#normalize SimWeight#normalize(float,float)}.</li>
             <li>
-                {@link org.apache.lucene.search.Weight#scorer(org.apache.lucene.index.LeafReaderContext, org.apache.lucene.util.Bits)
-                  scorer(LeafReaderContext context, Bits acceptDocs)} &mdash;
+                {@link org.apache.lucene.search.Weight#scorer scorer()} &mdash;
                 Construct a new {@link org.apache.lucene.search.Scorer Scorer} for this Weight. See <a href="#scorerClass">The Scorer Class</a>
                 below for help defining a Scorer. As the name implies, the Scorer is responsible for doing the actual scoring of documents 
                 given the Query.
             </li>
             <li>
-                {@link org.apache.lucene.search.Weight#bulkScorer(org.apache.lucene.index.LeafReaderContext, org.apache.lucene.util.Bits)
-                  scorer(LeafReaderContext context, Bits acceptDocs)} &mdash;
+                {@link org.apache.lucene.search.Weight#bulkScorer bulkScorer()} &mdash;
                 Construct a new {@link org.apache.lucene.search.BulkScorer BulkScorer} for this Weight. See <a href="#bulkScorerClass">The BulkScorer Class</a>
                 below for help defining a BulkScorer. This is an optional method, and most queries do not implement it.
             </li>
Index: lucene/core/src/java/org/apache/lucene/search/payloads/PayloadNearQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/payloads/PayloadNearQuery.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/payloads/PayloadNearQuery.java	(working copy)
@@ -148,7 +148,7 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       return new PayloadNearSpanScorer(query.getSpans(context, acceptDocs, termContexts), this,
           similarity, similarity.simScorer(stats, context));
     }
@@ -155,7 +155,7 @@
     
     @Override
     public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-      PayloadNearSpanScorer scorer = (PayloadNearSpanScorer) scorer(context, context.reader().getLiveDocs());
+      PayloadNearSpanScorer scorer = (PayloadNearSpanScorer) scorer(context, context.reader().getLiveDocs(), true);
       if (scorer != null) {
         int newDoc = scorer.advance(doc);
         if (newDoc == doc) {
Index: lucene/core/src/java/org/apache/lucene/search/payloads/PayloadTermQuery.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/payloads/PayloadTermQuery.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/payloads/PayloadTermQuery.java	(working copy)
@@ -79,7 +79,7 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       return new PayloadTermSpanScorer((TermSpans) query.getSpans(context, acceptDocs, termContexts),
           this, similarity.simScorer(stats, context));
     }
@@ -176,7 +176,7 @@
     
     @Override
     public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-      PayloadTermSpanScorer scorer = (PayloadTermSpanScorer) scorer(context, context.reader().getLiveDocs());
+      PayloadTermSpanScorer scorer = (PayloadTermSpanScorer) scorer(context, context.reader().getLiveDocs(), true);
       if (scorer != null) {
         int newDoc = scorer.advance(doc);
         if (newDoc == doc) {
Index: lucene/core/src/java/org/apache/lucene/search/spans/SpanWeight.java
===================================================================
--- lucene/core/src/java/org/apache/lucene/search/spans/SpanWeight.java	(revision 1657441)
+++ lucene/core/src/java/org/apache/lucene/search/spans/SpanWeight.java	(working copy)
@@ -81,7 +81,7 @@
   }
 
   @Override
-  public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+  public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
     if (stats == null) {
       return null;
     } else {
@@ -91,7 +91,7 @@
 
   @Override
   public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-    SpanScorer scorer = (SpanScorer) scorer(context, context.reader().getLiveDocs());
+    SpanScorer scorer = (SpanScorer) scorer(context, context.reader().getLiveDocs(), true);
     if (scorer != null) {
       int newDoc = scorer.advance(doc);
       if (newDoc == doc) {
Index: lucene/core/src/test/org/apache/lucene/index/TestOmitTf.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/index/TestOmitTf.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/index/TestOmitTf.java	(working copy)
@@ -437,6 +437,11 @@
     protected void doSetNextReader(LeafReaderContext context) throws IOException {
       docBase = context.docBase;
     }
+    
+    @Override
+    public boolean needsScores() {
+      return false;
+    }
   }
   
   /** test that when freqs are omitted, that totalTermFreq and sumTotalTermFreq are -1 */
Index: lucene/core/src/test/org/apache/lucene/search/JustCompileSearch.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/JustCompileSearch.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/JustCompileSearch.java	(working copy)
@@ -53,6 +53,10 @@
       throw new UnsupportedOperationException(UNSUPPORTED_MSG);
     }
 
+    @Override
+    public boolean needsScores() {
+      throw new UnsupportedOperationException(UNSUPPORTED_MSG);
+    }
   }
   
   static final class JustCompileDocIdSet extends DocIdSet {
@@ -253,7 +257,11 @@
     public TopDocs topDocs( int start, int end ) {
         throw new UnsupportedOperationException( UNSUPPORTED_MSG );
     }
-    
+
+    @Override
+    public boolean needsScores() {
+      throw new UnsupportedOperationException( UNSUPPORTED_MSG );
+    }
   }
 
   static final class JustCompileWeight extends Weight {
@@ -279,7 +287,7 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) {
       throw new UnsupportedOperationException(UNSUPPORTED_MSG);
     }
     
Index: lucene/core/src/test/org/apache/lucene/search/MultiCollectorTest.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/MultiCollectorTest.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/MultiCollectorTest.java	(working copy)
@@ -46,6 +46,10 @@
       setScorerCalled = true;
     }
 
+    @Override
+    public boolean needsScores() {
+      return true;
+    }
   }
 
   @Test
Index: lucene/core/src/test/org/apache/lucene/search/TestBooleanCoord.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestBooleanCoord.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestBooleanCoord.java	(working copy)
@@ -707,7 +707,7 @@
   private void assertScore(final float expected, Query query) throws Exception {
     // test in-order
     Weight weight = searcher.createNormalizedWeight(query);
-    Scorer scorer = weight.scorer(reader.leaves().get(0), null);
+    Scorer scorer = weight.scorer(reader.leaves().get(0), null, true);
     assertTrue(scorer.docID() == -1 || scorer.docID() == DocIdSetIterator.NO_MORE_DOCS);
     assertEquals(0, scorer.nextDoc());
     assertEquals(expected, scorer.score(), 0.0001f);
@@ -714,7 +714,7 @@
     
     // test bulk scorer
     final AtomicBoolean seen = new AtomicBoolean(false);
-    BulkScorer bulkScorer = weight.bulkScorer(reader.leaves().get(0), null);
+    BulkScorer bulkScorer = weight.bulkScorer(reader.leaves().get(0), null, true);
     assertNotNull(bulkScorer);
     bulkScorer.score(new LeafCollector() {
       Scorer scorer;
Index: lucene/core/src/test/org/apache/lucene/search/TestBooleanOr.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestBooleanOr.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestBooleanOr.java	(working copy)
@@ -189,7 +189,7 @@
     Weight w = s.createNormalizedWeight(bq);
 
     assertEquals(1, s.getIndexReader().leaves().size());
-    BulkScorer scorer = w.bulkScorer(s.getIndexReader().leaves().get(0), null);
+    BulkScorer scorer = w.bulkScorer(s.getIndexReader().leaves().get(0), null, true);
 
     final FixedBitSet hits = new FixedBitSet(docCount);
     final AtomicInteger end = new AtomicInteger();
@@ -200,6 +200,11 @@
           assertTrue("collected doc=" + doc + " beyond max=" + end, doc < end.intValue());
           hits.set(doc);
         }
+        
+        @Override
+        public boolean needsScores() {
+          return false;
+        }
       };
 
     while (end.intValue() < docCount) {
Index: lucene/core/src/test/org/apache/lucene/search/TestBooleanQuery.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestBooleanQuery.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestBooleanQuery.java	(working copy)
@@ -235,7 +235,7 @@
 
       Weight weight = s.createNormalizedWeight(q);
 
-      Scorer scorer = weight.scorer(s.leafContexts.get(0), null);
+      Scorer scorer = weight.scorer(s.leafContexts.get(0), null, true);
 
       // First pass: just use .nextDoc() to gather all hits
       final List<ScoreDoc> hits = new ArrayList<>();
@@ -252,7 +252,7 @@
       for(int iter2=0;iter2<10;iter2++) {
 
         weight = s.createNormalizedWeight(q);
-        scorer = weight.scorer(s.leafContexts.get(0), null);
+        scorer = weight.scorer(s.leafContexts.get(0), null, true);
 
         if (VERBOSE) {
           System.out.println("  iter2=" + iter2);
Index: lucene/core/src/test/org/apache/lucene/search/TestBooleanQueryVisitSubscorers.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestBooleanQueryVisitSubscorers.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestBooleanQueryVisitSubscorers.java	(working copy)
@@ -234,6 +234,11 @@
     public List<String> getSummaries() {
       return summaries;
     }
+    
+    @Override
+    public boolean needsScores() {
+      return true;
+    }
 
     @Override
     public LeafCollector getLeafCollector(LeafReaderContext context) throws IOException {
@@ -282,8 +287,8 @@
     public Weight createWeight(IndexSearcher searcher) throws IOException {
       return new BooleanWeight(searcher, false) {
         @Override
-        public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
-          Scorer scorer = scorer(context, acceptDocs);
+        public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
+          Scorer scorer = scorer(context, acceptDocs, needsScores);
           if (scorer == null) {
             return null;
           }
Index: lucene/core/src/test/org/apache/lucene/search/TestBooleanScorer.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestBooleanScorer.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestBooleanScorer.java	(working copy)
@@ -92,12 +92,12 @@
         }
 
         @Override
-        public Scorer scorer(LeafReaderContext context, Bits acceptDocs) {
+        public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) {
           throw new UnsupportedOperationException();
         }
 
         @Override
-        public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs) {
+        public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) {
           return new BulkScorer() {
             @Override
             public int score(LeafCollector collector, int min, int max) throws IOException {
Index: lucene/core/src/test/org/apache/lucene/search/TestCachingCollector.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestCachingCollector.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestCachingCollector.java	(working copy)
@@ -56,6 +56,11 @@
 
     @Override
     public void collect(int doc) throws IOException {}
+    
+    @Override
+    public boolean needsScores() {
+      return false;
+    }
 
   }
 
@@ -79,6 +84,11 @@
           assertEquals(prevDocID + 1, doc);
           prevDocID = doc;
         }
+        
+        @Override
+        public boolean needsScores() {
+          return false;
+        }
       });
     }
   }
Index: lucene/core/src/test/org/apache/lucene/search/TestConstantScoreQuery.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestConstantScoreQuery.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestConstantScoreQuery.java	(working copy)
@@ -67,6 +67,11 @@
         assertEquals("Score differs from expected", expectedScore, this.scorer.score(), 0);
         count[0]++;
       }
+      
+      @Override
+      public boolean needsScores() {
+        return true;
+      }
     });
     assertEquals("invalid number of results", 1, count[0]);
   }
Index: lucene/core/src/test/org/apache/lucene/search/TestDisjunctionMaxQuery.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestDisjunctionMaxQuery.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestDisjunctionMaxQuery.java	(working copy)
@@ -180,7 +180,7 @@
     assertTrue(s.getTopReaderContext() instanceof LeafReaderContext);
     final Weight dw = s.createNormalizedWeight(dq);
     LeafReaderContext context = (LeafReaderContext)s.getTopReaderContext();
-    final Scorer ds = dw.scorer(context, context.reader().getLiveDocs());
+    final Scorer ds = dw.scorer(context, context.reader().getLiveDocs(), true);
     final boolean skipOk = ds.advance(3) != DocIdSetIterator.NO_MORE_DOCS;
     if (skipOk) {
       fail("firsttime skipTo found a match? ... "
@@ -196,7 +196,7 @@
     QueryUtils.check(random(), dq, s);
     final Weight dw = s.createNormalizedWeight(dq);
     LeafReaderContext context = (LeafReaderContext)s.getTopReaderContext();
-    final Scorer ds = dw.scorer(context, context.reader().getLiveDocs());
+    final Scorer ds = dw.scorer(context, context.reader().getLiveDocs(), true);
     assertTrue("firsttime skipTo found no match",
         ds.advance(3) != DocIdSetIterator.NO_MORE_DOCS);
     assertEquals("found wrong docid", "d4", r.document(ds.docID()).get("id"));
Index: lucene/core/src/test/org/apache/lucene/search/TestDocBoost.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestDocBoost.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestDocBoost.java	(working copy)
@@ -74,6 +74,10 @@
          protected void doSetNextReader(LeafReaderContext context) throws IOException {
            base = context.docBase;
          }
+         @Override
+         public boolean needsScores() {
+           return true;
+         }
        });
 
     float lastScore = 0.0f;
Index: lucene/core/src/test/org/apache/lucene/search/TestEarlyTermination.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestEarlyTermination.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestEarlyTermination.java	(working copy)
@@ -80,7 +80,11 @@
             collectionTerminated = false;
           }
         }
-
+        
+        @Override
+        public boolean needsScores() {
+          return false;
+        }
       };
 
       searcher.search(new MatchAllDocsQuery(), collector);
Index: lucene/core/src/test/org/apache/lucene/search/TestMinShouldMatch2.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestMinShouldMatch2.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestMinShouldMatch2.java	(working copy)
@@ -131,11 +131,11 @@
     case DOC_VALUES:
       return new SlowMinShouldMatchScorer(weight, reader, searcher);
     case SCORER:
-      return weight.scorer(reader.getContext(), null);
+      return weight.scorer(reader.getContext(), null, true);
     case BULK_SCORER:
-      final BulkScorer bulkScorer = weight.booleanScorer(reader.getContext(), null);
+      final BulkScorer bulkScorer = weight.booleanScorer(reader.getContext(), null, true);
       if (bulkScorer == null) {
-        if (weight.scorer(reader.getContext(), null) != null) {
+        if (weight.scorer(reader.getContext(), null, true) != null) {
           throw new AssertionError("BooleanScorer should be applicable for this query");
         }
         return null;
Index: lucene/core/src/test/org/apache/lucene/search/TestMultiTermConstantScore.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestMultiTermConstantScore.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestMultiTermConstantScore.java	(working copy)
@@ -241,6 +241,11 @@
       protected void doSetNextReader(LeafReaderContext context) throws IOException {
         base = context.docBase;
       }
+      
+      @Override
+      public boolean needsScores() {
+        return true;
+      }
     });
 
     //
Index: lucene/core/src/test/org/apache/lucene/search/TestNeedsScores.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestNeedsScores.java	(revision 0)
+++ lucene/core/src/test/org/apache/lucene/search/TestNeedsScores.java	(working copy)
@@ -0,0 +1,185 @@
+package org.apache.lucene.search;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.io.IOException;
+import java.util.Set;
+
+import org.apache.lucene.document.Document;
+import org.apache.lucene.document.Field;
+import org.apache.lucene.document.TextField;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.index.RandomIndexWriter;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.util.Bits;
+import org.apache.lucene.util.IOUtils;
+import org.apache.lucene.util.LuceneTestCase;
+
+public class TestNeedsScores extends LuceneTestCase {
+  Directory dir;
+  IndexReader reader;
+  IndexSearcher searcher;
+  
+  @Override
+  public void setUp() throws Exception {
+    super.setUp();
+    dir = newDirectory();
+    RandomIndexWriter iw = new RandomIndexWriter(random(), dir);
+    for (int i = 0; i < 5; i++) {
+      Document doc = new Document();
+      doc.add(new TextField("field", "this is document " + i, Field.Store.NO));
+      iw.addDocument(doc);
+    }
+    reader = iw.getReader();
+    searcher = newSearcher(reader);
+    iw.close();
+  }
+
+  @Override
+  public void tearDown() throws Exception {
+    IOUtils.close(reader, dir);
+    super.tearDown();
+  }
+
+  /** prohibited clauses in booleanquery don't need scoring */
+  public void testProhibitedClause() throws Exception {
+    Query required = new TermQuery(new Term("field", "this"));
+    Query prohibited = new TermQuery(new Term("field", "3"));
+    BooleanQuery bq = new BooleanQuery();
+    bq.add(new AssertNeedsScores(required, true), BooleanClause.Occur.MUST);
+    bq.add(new AssertNeedsScores(prohibited, false), BooleanClause.Occur.MUST_NOT);
+    assertEquals(4, searcher.search(bq, 5).totalHits); // we exclude 3
+  }
+  
+  /** nested inside constant score query */
+  public void testConstantScoreQuery() throws Exception {
+    Query term = new TermQuery(new Term("field", "this"));
+    Query constantScore = new ConstantScoreQuery(new AssertNeedsScores(term, false));
+    assertEquals(5, searcher.search(constantScore, 5).totalHits);
+  }
+  
+  /** when converted to a filter */
+  public void testQueryWrapperFilter() throws Exception {
+    Query query = new MatchAllDocsQuery();
+    Query term = new TermQuery(new Term("field", "this"));
+    Filter filter = new QueryWrapperFilter(new AssertNeedsScores(term, false));
+    assertEquals(5, searcher.search(query, filter, 5).totalHits);
+  }
+  
+  /** when not sorting by score */
+  public void testSortByField() throws Exception {
+    Query query = new AssertNeedsScores(new MatchAllDocsQuery(), false);
+    assertEquals(5, searcher.search(query, 5, Sort.INDEXORDER).totalHits);
+  }
+  
+  /** when sorting by score */
+  public void testSortByScore() throws Exception {
+    Query query = new AssertNeedsScores(new MatchAllDocsQuery(), true);
+    assertEquals(5, searcher.search(query, 5, Sort.RELEVANCE).totalHits);
+  }
+
+  /** 
+   * Wraps a query, checking that the needsScores param 
+   * passed to Weight.scorer is the expected value.
+   */
+  static class AssertNeedsScores extends Query {
+    final Query in;
+    final boolean value;
+    
+    AssertNeedsScores(Query in, boolean value) {
+      this.in = in;
+      this.value = value;
+    }
+
+    @Override
+    public Weight createWeight(IndexSearcher searcher) throws IOException {
+      final Weight w = in.createWeight(searcher);
+      return new Weight() {
+        @Override
+        public Explanation explain(LeafReaderContext context, int doc) throws IOException {
+          return w.explain(context, doc);
+        }
+
+        @Override
+        public Query getQuery() {
+          return AssertNeedsScores.this;
+        }
+
+        @Override
+        public float getValueForNormalization() throws IOException {
+          return w.getValueForNormalization();
+        }
+
+        @Override
+        public void normalize(float norm, float topLevelBoost) {
+          w.normalize(norm, topLevelBoost);
+        }
+
+        @Override
+        public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
+          assertEquals("query=" + in, value, needsScores);
+          return w.scorer(context, acceptDocs, needsScores);
+        }
+      };
+    }
+
+    @Override
+    public Query rewrite(IndexReader reader) throws IOException {
+      Query in2 = in.rewrite(reader);
+      if (in2 == in) {
+        return this;
+      } else {
+        return new AssertNeedsScores(in2, value);
+      }
+    }
+
+    @Override
+    public void extractTerms(Set<Term> terms) {
+      in.extractTerms(terms);
+    }
+
+    @Override
+    public int hashCode() {
+      final int prime = 31;
+      int result = super.hashCode();
+      result = prime * result + ((in == null) ? 0 : in.hashCode());
+      result = prime * result + (value ? 1231 : 1237);
+      return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+      if (this == obj) return true;
+      if (!super.equals(obj)) return false;
+      if (getClass() != obj.getClass()) return false;
+      AssertNeedsScores other = (AssertNeedsScores) obj;
+      if (in == null) {
+        if (other.in != null) return false;
+      } else if (!in.equals(other.in)) return false;
+      if (value != other.value) return false;
+      return true;
+    }
+
+    @Override
+    public String toString(String field) {
+      return "asserting(" + in.toString(field) + ")";
+    }
+  }
+}

Property changes on: lucene/core/src/test/org/apache/lucene/search/TestNeedsScores.java
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Index: lucene/core/src/test/org/apache/lucene/search/TestQueryRescorer.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestQueryRescorer.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestQueryRescorer.java	(working copy)
@@ -443,7 +443,7 @@
         }
 
         @Override
-        public Scorer scorer(final LeafReaderContext context, Bits acceptDocs) throws IOException {
+        public Scorer scorer(final LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
 
           return new Scorer(null) {
             int docID = -1;
Index: lucene/core/src/test/org/apache/lucene/search/TestScoreCachingWrappingScorer.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestScoreCachingWrappingScorer.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestScoreCachingWrappingScorer.java	(working copy)
@@ -90,6 +90,11 @@
     @Override public void setScorer(Scorer scorer) {
       this.scorer = new ScoreCachingWrappingScorer(scorer);
     }
+    
+    @Override
+    public boolean needsScores() {
+      return true;
+    }
 
   }
 
Index: lucene/core/src/test/org/apache/lucene/search/TestScorerPerf.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestScorerPerf.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestScorerPerf.java	(working copy)
@@ -115,6 +115,11 @@
     protected void doSetNextReader(LeafReaderContext context) throws IOException {
       docBase = context.docBase;
     }
+    
+    @Override
+    public boolean needsScores() {
+      return false;
+    }
   }
 
 
Index: lucene/core/src/test/org/apache/lucene/search/TestSimilarity.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestSimilarity.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestSimilarity.java	(working copy)
@@ -86,7 +86,8 @@
         public final void collect(int doc) throws IOException {
            assertEquals(1.0f, scorer.score(), 0);
          }
-        public boolean acceptsDocsOutOfOrder() {
+         @Override
+         public boolean needsScores() {
            return true;
          }
        });
@@ -111,6 +112,10 @@
          protected void doSetNextReader(LeafReaderContext context) throws IOException {
            base = context.docBase;
          }
+         @Override
+         public boolean needsScores() {
+           return true;
+         }
        });
 
     PhraseQuery pq = new PhraseQuery();
@@ -129,6 +134,10 @@
            //System.out.println("Doc=" + doc + " score=" + score);
            assertEquals(1.0f, scorer.score(), 0);
          }
+         @Override
+         public boolean needsScores() {
+           return true;
+         }
        });
 
     pq.setSlop(2);
@@ -144,6 +153,10 @@
         //System.out.println("Doc=" + doc + " score=" + score);
         assertEquals(2.0f, scorer.score(), 0);
       }
+      @Override
+      public boolean needsScores() {
+        return true;
+      }
     });
 
     reader.close();
Index: lucene/core/src/test/org/apache/lucene/search/TestSloppyPhraseQuery.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestSloppyPhraseQuery.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestSloppyPhraseQuery.java	(working copy)
@@ -191,6 +191,11 @@
       totalHits++;
       max = Math.max(max, scorer.freq());
     }
+    
+    @Override
+    public boolean needsScores() {
+      return true;
+    }
   }
   
   /** checks that no scores or freqs are infinite */
@@ -208,6 +213,11 @@
         assertFalse(Float.isInfinite(scorer.freq()));
         assertFalse(Float.isInfinite(scorer.score()));
       }
+      
+      @Override
+      public boolean needsScores() {
+        return true;
+      }
     });
     QueryUtils.check(random(), pq, searcher);
   }
Index: lucene/core/src/test/org/apache/lucene/search/TestTermScorer.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestTermScorer.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestTermScorer.java	(working copy)
@@ -78,7 +78,7 @@
     Weight weight = indexSearcher.createNormalizedWeight(termQuery);
     assertTrue(indexSearcher.getTopReaderContext() instanceof LeafReaderContext);
     LeafReaderContext context = (LeafReaderContext)indexSearcher.getTopReaderContext();
-    BulkScorer ts = weight.bulkScorer(context, context.reader().getLiveDocs());
+    BulkScorer ts = weight.bulkScorer(context, context.reader().getLiveDocs(), true);
     // we have 2 documents with the term all in them, one document for all the
     // other values
     final List<TestHit> docs = new ArrayList<>();
@@ -107,6 +107,11 @@
       protected void doSetNextReader(LeafReaderContext context) throws IOException {
         base = context.docBase;
       }
+      
+      @Override
+      public boolean needsScores() {
+        return true;
+      }
     });
     assertTrue("docs Size: " + docs.size() + " is not: " + 2, docs.size() == 2);
     TestHit doc0 = docs.get(0);
@@ -135,7 +140,7 @@
     Weight weight = indexSearcher.createNormalizedWeight(termQuery);
     assertTrue(indexSearcher.getTopReaderContext() instanceof LeafReaderContext);
     LeafReaderContext context = (LeafReaderContext) indexSearcher.getTopReaderContext();
-    Scorer ts = weight.scorer(context, context.reader().getLiveDocs());
+    Scorer ts = weight.scorer(context, context.reader().getLiveDocs(), true);
     assertTrue("next did not return a doc",
         ts.nextDoc() != DocIdSetIterator.NO_MORE_DOCS);
     assertTrue("score is not correct", ts.score() == 1.6931472f);
@@ -154,7 +159,7 @@
     Weight weight = indexSearcher.createNormalizedWeight(termQuery);
     assertTrue(indexSearcher.getTopReaderContext() instanceof LeafReaderContext);
     LeafReaderContext context = (LeafReaderContext) indexSearcher.getTopReaderContext();
-    Scorer ts = weight.scorer(context, context.reader().getLiveDocs());
+    Scorer ts = weight.scorer(context, context.reader().getLiveDocs(), true);
     assertTrue("Didn't skip", ts.advance(3) != DocIdSetIterator.NO_MORE_DOCS);
     // The next doc should be doc 5
     assertTrue("doc should be number 5", ts.docID() == 5);
Index: lucene/core/src/test/org/apache/lucene/search/TestTimeLimitingCollector.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestTimeLimitingCollector.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestTimeLimitingCollector.java	(working copy)
@@ -356,6 +356,11 @@
     protected void doSetNextReader(LeafReaderContext context) throws IOException {
       docBase = context.docBase;
     }
+    
+    @Override
+    public boolean needsScores() {
+      return false;
+    }
 
   }
 
Index: lucene/core/src/test/org/apache/lucene/search/TestTopDocsCollector.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/TestTopDocsCollector.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/TestTopDocsCollector.java	(working copy)
@@ -70,6 +70,11 @@
         }
       };
     }
+    
+    @Override
+    public boolean needsScores() {
+      return false;
+    }
 
   }
 
Index: lucene/core/src/test/org/apache/lucene/search/spans/TestNearSpansOrdered.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/spans/TestNearSpansOrdered.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/spans/TestNearSpansOrdered.java	(working copy)
@@ -183,7 +183,7 @@
     Weight w = searcher.createNormalizedWeight(q);
     IndexReaderContext topReaderContext = searcher.getTopReaderContext();
     LeafReaderContext leave = topReaderContext.leaves().get(0);
-    Scorer s = w.scorer(leave, leave.reader().getLiveDocs());
+    Scorer s = w.scorer(leave, leave.reader().getLiveDocs(), true);
     assertEquals(1, s.advance(1));
   }
 
Index: lucene/core/src/test/org/apache/lucene/search/spans/TestSpans.java
===================================================================
--- lucene/core/src/test/org/apache/lucene/search/spans/TestSpans.java	(revision 1657441)
+++ lucene/core/src/test/org/apache/lucene/search/spans/TestSpans.java	(working copy)
@@ -429,7 +429,7 @@
                                 slop,
                                 ordered);
   
-        spanScorer = searcher.createNormalizedWeight(snq).scorer(ctx, ctx.reader().getLiveDocs());
+        spanScorer = searcher.createNormalizedWeight(snq).scorer(ctx, ctx.reader().getLiveDocs(), true);
       } finally {
         searcher.setSimilarity(oldSim);
       }
Index: lucene/facet/src/java/org/apache/lucene/facet/DrillSidewaysQuery.java
===================================================================
--- lucene/facet/src/java/org/apache/lucene/facet/DrillSidewaysQuery.java	(revision 1657441)
+++ lucene/facet/src/java/org/apache/lucene/facet/DrillSidewaysQuery.java	(working copy)
@@ -111,17 +111,17 @@
       }
 
       @Override
-      public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+      public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
         // We can only run as a top scorer:
         throw new UnsupportedOperationException();
       }
 
       @Override
-      public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+      public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
 
         // TODO: it could be better if we take acceptDocs
         // into account instead of baseScorer?
-        Scorer baseScorer = baseWeight.scorer(context, acceptDocs);
+        Scorer baseScorer = baseWeight.scorer(context, acceptDocs, needsScores);
 
         DrillSidewaysScorer.DocsAndCost[] dims = new DrillSidewaysScorer.DocsAndCost[drillDowns.length];
         int nullCount = 0;
@@ -166,7 +166,7 @@
               dims[dim].disi = disi;
             }
           } else {
-            DocIdSetIterator disi = ((Weight) drillDowns[dim]).scorer(context, null);
+            DocIdSetIterator disi = ((Weight) drillDowns[dim]).scorer(context, null, needsScores);
             if (disi == null) {
               nullCount++;
               continue;
Index: lucene/facet/src/java/org/apache/lucene/facet/FacetsCollector.java
===================================================================
--- lucene/facet/src/java/org/apache/lucene/facet/FacetsCollector.java	(revision 1657441)
+++ lucene/facet/src/java/org/apache/lucene/facet/FacetsCollector.java	(working copy)
@@ -169,6 +169,11 @@
   }
 
   @Override
+  public boolean needsScores() {
+    return true;
+  }
+
+  @Override
   public final void setScorer(Scorer scorer) throws IOException {
     this.scorer = scorer;
   }
Index: lucene/facet/src/test/org/apache/lucene/facet/AssertingSubDocsAtOnceCollector.java
===================================================================
--- lucene/facet/src/test/org/apache/lucene/facet/AssertingSubDocsAtOnceCollector.java	(revision 1657441)
+++ lucene/facet/src/test/org/apache/lucene/facet/AssertingSubDocsAtOnceCollector.java	(working copy)
@@ -54,4 +54,9 @@
       }
     }
   }
+
+  @Override
+  public boolean needsScores() {
+    return false;
+  }
 }
Index: lucene/facet/src/test/org/apache/lucene/facet/TestDrillSideways.java
===================================================================
--- lucene/facet/src/test/org/apache/lucene/facet/TestDrillSideways.java	(revision 1657441)
+++ lucene/facet/src/test/org/apache/lucene/facet/TestDrillSideways.java	(working copy)
@@ -682,6 +682,11 @@
                              protected void doSetNextReader(LeafReaderContext context) throws IOException {
                                lastDocID = -1;
                              }
+
+                            @Override
+                            public boolean needsScores() {
+                              return false;
+                            }
                            });
 
       // Also separately verify that DS respects the
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/BlockGroupingCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/BlockGroupingCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/BlockGroupingCollector.java	(working copy)
@@ -528,4 +528,9 @@
       leafComparators[i] = comparators[i].getLeafComparator(readerContext);
     }
   }
+
+  @Override
+  public boolean needsScores() {
+    return needsScores;
+  }
 }
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionAllGroupHeadsCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionAllGroupHeadsCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionAllGroupHeadsCollector.java	(working copy)
@@ -152,4 +152,9 @@
       this.doc = doc + readerContext.docBase;
     }
   }
+
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't: e.g. return sortWithinGroup.needsScores()
+  }
 }
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionAllGroupsCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionAllGroupsCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionAllGroupsCollector.java	(working copy)
@@ -80,4 +80,9 @@
     filler = values.getValueFiller();
     mval = filler.getValue();
   }
+  
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't?
+  }
 }
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionDistinctValuesCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionDistinctValuesCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionDistinctValuesCollector.java	(working copy)
@@ -89,4 +89,9 @@
     }
 
   }
+  
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't?
+  }
 }
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionFirstPassGroupingCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionFirstPassGroupingCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionFirstPassGroupingCollector.java	(working copy)
@@ -84,4 +84,8 @@
     mval = filler.getValue();
   }
 
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't?
+  }
 }
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionSecondPassGroupingCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionSecondPassGroupingCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/function/FunctionSecondPassGroupingCollector.java	(working copy)
@@ -78,4 +78,8 @@
     mval = filler.getValue();
   }
 
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't?
+  }
 }
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermAllGroupHeadsCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermAllGroupHeadsCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermAllGroupHeadsCollector.java	(working copy)
@@ -623,4 +623,9 @@
     }
 
   }
+  
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't?
+  }
 }
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermAllGroupsCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermAllGroupsCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermAllGroupsCollector.java	(working copy)
@@ -118,4 +118,9 @@
       }
     }
   }
+  
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't?
+  }
 }
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermDistinctValuesCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermDistinctValuesCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermDistinctValuesCollector.java	(working copy)
@@ -141,4 +141,8 @@
     }
   }
 
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't?
+  }
 }
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermFirstPassGroupingCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermFirstPassGroupingCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermFirstPassGroupingCollector.java	(working copy)
@@ -91,4 +91,9 @@
     super.doSetNextReader(readerContext);
     index = DocValues.getSorted(readerContext.reader(), groupField);
   }
+  
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't?
+  }
 }
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermGroupFacetCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermGroupFacetCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermGroupFacetCollector.java	(working copy)
@@ -75,6 +75,11 @@
     groupedFacetHits = new ArrayList<>(initialSize);
     segmentGroupedFacetHits = new SentinelIntSet(initialSize, Integer.MIN_VALUE);
   }
+  
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't?
+  }
 
   // Implementation for single valued facet fields.
   static class SV extends TermGroupFacetCollector {
Index: lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermSecondPassGroupingCollector.java
===================================================================
--- lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermSecondPassGroupingCollector.java	(revision 1657441)
+++ lucene/grouping/src/java/org/apache/lucene/search/grouping/term/TermSecondPassGroupingCollector.java	(working copy)
@@ -76,4 +76,9 @@
     }
     return null;
   }
+  
+  @Override
+  public boolean needsScores() {
+    return true; // TODO, maybe we don't?
+  }
 }
Index: lucene/highlighter/src/test/org/apache/lucene/search/highlight/HighlighterPhraseTest.java
===================================================================
--- lucene/highlighter/src/test/org/apache/lucene/search/highlight/HighlighterPhraseTest.java	(revision 1657441)
+++ lucene/highlighter/src/test/org/apache/lucene/search/highlight/HighlighterPhraseTest.java	(working copy)
@@ -133,6 +133,11 @@
         public void setScorer(org.apache.lucene.search.Scorer scorer) {
           // Do Nothing
         }
+
+        @Override
+        public boolean needsScores() {
+          return false;
+        }
       });
       assertEquals(1, bitset.cardinality());
       final int maxDoc = indexReader.maxDoc();
Index: lucene/join/src/java/org/apache/lucene/search/join/TermsCollector.java
===================================================================
--- lucene/join/src/java/org/apache/lucene/search/join/TermsCollector.java	(revision 1657441)
+++ lucene/join/src/java/org/apache/lucene/search/join/TermsCollector.java	(working copy)
@@ -103,4 +103,8 @@
     }
   }
 
+  @Override
+  public boolean needsScores() {
+    return false;
+  }
 }
Index: lucene/join/src/java/org/apache/lucene/search/join/TermsIncludingScoreQuery.java
===================================================================
--- lucene/join/src/java/org/apache/lucene/search/join/TermsIncludingScoreQuery.java	(revision 1657441)
+++ lucene/join/src/java/org/apache/lucene/search/join/TermsIncludingScoreQuery.java	(working copy)
@@ -167,7 +167,7 @@
       }
 
       @Override
-      public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+      public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
         Terms terms = context.reader().terms(field);
         if (terms == null) {
           return null;
Index: lucene/join/src/java/org/apache/lucene/search/join/TermsWithScoreCollector.java
===================================================================
--- lucene/join/src/java/org/apache/lucene/search/join/TermsWithScoreCollector.java	(revision 1657441)
+++ lucene/join/src/java/org/apache/lucene/search/join/TermsWithScoreCollector.java	(working copy)
@@ -247,4 +247,8 @@
     }
   }
 
+  @Override
+  public boolean needsScores() {
+    return true;
+  }
 }
Index: lucene/join/src/java/org/apache/lucene/search/join/ToChildBlockJoinQuery.java
===================================================================
--- lucene/join/src/java/org/apache/lucene/search/join/ToChildBlockJoinQuery.java	(revision 1657441)
+++ lucene/join/src/java/org/apache/lucene/search/join/ToChildBlockJoinQuery.java	(working copy)
@@ -128,9 +128,9 @@
     // NOTE: acceptDocs applies (and is checked) only in the
     // child document space
     @Override
-    public Scorer scorer(LeafReaderContext readerContext, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext readerContext, Bits acceptDocs, boolean needsScores) throws IOException {
 
-      final Scorer parentScorer = parentWeight.scorer(readerContext, null);
+      final Scorer parentScorer = parentWeight.scorer(readerContext, null, needsScores);
 
       if (parentScorer == null) {
         // No matches
Index: lucene/join/src/java/org/apache/lucene/search/join/ToParentBlockJoinCollector.java
===================================================================
--- lucene/join/src/java/org/apache/lucene/search/join/ToParentBlockJoinCollector.java	(revision 1657441)
+++ lucene/join/src/java/org/apache/lucene/search/join/ToParentBlockJoinCollector.java	(working copy)
@@ -482,4 +482,9 @@
   public float getMaxScore() {
     return maxScore;
   }
+
+  @Override
+  public boolean needsScores() {
+    return trackScores || trackMaxScore || sort.needsScores();
+  }
 }
Index: lucene/join/src/java/org/apache/lucene/search/join/ToParentBlockJoinIndexSearcher.java
===================================================================
--- lucene/join/src/java/org/apache/lucene/search/join/ToParentBlockJoinIndexSearcher.java	(revision 1657441)
+++ lucene/join/src/java/org/apache/lucene/search/join/ToParentBlockJoinIndexSearcher.java	(working copy)
@@ -55,7 +55,7 @@
       // we force the use of Scorer (not BulkScorer) to make sure
       // that the scorer passed to LeafCollector.setScorer supports
       // Scorer.getChildren
-      Scorer scorer = weight.scorer(ctx, ctx.reader().getLiveDocs());
+      Scorer scorer = weight.scorer(ctx, ctx.reader().getLiveDocs(), true);
       if (scorer != null) {
         final LeafCollector leafCollector = collector.getLeafCollector(ctx);
         leafCollector.setScorer(scorer);
Index: lucene/join/src/java/org/apache/lucene/search/join/ToParentBlockJoinQuery.java
===================================================================
--- lucene/join/src/java/org/apache/lucene/search/join/ToParentBlockJoinQuery.java	(revision 1657441)
+++ lucene/join/src/java/org/apache/lucene/search/join/ToParentBlockJoinQuery.java	(working copy)
@@ -160,9 +160,9 @@
     // NOTE: acceptDocs applies (and is checked) only in the
     // parent document space
     @Override
-    public Scorer scorer(LeafReaderContext readerContext, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext readerContext, Bits acceptDocs, boolean needsScores) throws IOException {
 
-      final Scorer childScorer = childWeight.scorer(readerContext, readerContext.reader().getLiveDocs());
+      final Scorer childScorer = childWeight.scorer(readerContext, readerContext.reader().getLiveDocs(), needsScores);
       if (childScorer == null) {
         // No matches
         return null;
@@ -188,7 +188,7 @@
 
     @Override
     public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-      BlockJoinScorer scorer = (BlockJoinScorer) scorer(context, context.reader().getLiveDocs());
+      BlockJoinScorer scorer = (BlockJoinScorer) scorer(context, context.reader().getLiveDocs(), true);
       if (scorer != null && scorer.advance(doc) == doc) {
         return scorer.explain(context.docBase);
       }
Index: lucene/join/src/test/org/apache/lucene/search/join/TestBlockJoin.java
===================================================================
--- lucene/join/src/test/org/apache/lucene/search/join/TestBlockJoin.java	(revision 1657441)
+++ lucene/join/src/test/org/apache/lucene/search/join/TestBlockJoin.java	(working copy)
@@ -1148,7 +1148,7 @@
 
     ToParentBlockJoinQuery q = new ToParentBlockJoinQuery(tq, parentFilter, ScoreMode.Avg);
     Weight weight = s.createNormalizedWeight(q);
-    DocIdSetIterator disi = weight.scorer(s.getIndexReader().leaves().get(0), null);
+    DocIdSetIterator disi = weight.scorer(s.getIndexReader().leaves().get(0), null, true);
     assertEquals(1, disi.advance(1));
     r.close();
     dir.close();
@@ -1182,7 +1182,7 @@
 
     ToParentBlockJoinQuery q = new ToParentBlockJoinQuery(tq, parentFilter, ScoreMode.Avg);
     Weight weight = s.createNormalizedWeight(q);
-    DocIdSetIterator disi = weight.scorer(s.getIndexReader().leaves().get(0), null);
+    DocIdSetIterator disi = weight.scorer(s.getIndexReader().leaves().get(0), null, true);
     assertEquals(2, disi.advance(0));
     r.close();
     dir.close();
Index: lucene/join/src/test/org/apache/lucene/search/join/TestJoinUtil.java
===================================================================
--- lucene/join/src/test/org/apache/lucene/search/join/TestJoinUtil.java	(revision 1657441)
+++ lucene/join/src/test/org/apache/lucene/search/join/TestJoinUtil.java	(working copy)
@@ -310,6 +310,11 @@
             assertFalse("optimized bulkScorer was not used for join query embedded in boolean query!", sawFive);
           }
         }
+        
+        @Override
+        public boolean needsScores() {
+          return false;
+        }
       });
 
     indexSearcher.getIndexReader().close();
@@ -495,6 +500,11 @@
               }
             };
           }
+          
+          @Override
+          public boolean needsScores() {
+            return topScoreDocCollector.needsScores();
+          }
         });
         // Asserting bit set...
         if (VERBOSE) {
@@ -673,6 +683,11 @@
           public void setScorer(Scorer scorer) {
             this.scorer = scorer;
           }
+
+          @Override
+          public boolean needsScores() {
+            return true;
+          }
         });
       } else {
         fromSearcher.search(new TermQuery(new Term("value", uniqueRandomValue)), new SimpleCollector() {
@@ -705,6 +720,11 @@
           public void setScorer(Scorer scorer) {
             this.scorer = scorer;
           }
+          
+          @Override
+          public boolean needsScores() {
+            return true;
+          }
         });
       }
 
@@ -757,6 +777,11 @@
 
           @Override
           public void setScorer(Scorer scorer) {}
+          
+          @Override
+          public boolean needsScores() {
+            return false;
+          }
         });
       }
       queryVals.put(uniqueRandomValue, docToJoinScore);
Index: lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java
===================================================================
--- lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java	(revision 1657441)
+++ lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java	(working copy)
@@ -568,7 +568,11 @@
         public void setScorer(Scorer scorer) {
           this.scorer = scorer;
         }
-
+        
+        @Override
+        public boolean needsScores() {
+          return true;
+        }
       });
       float score = scores[0];
       return score;
Index: lucene/queries/src/java/org/apache/lucene/queries/CustomScoreQuery.java
===================================================================
--- lucene/queries/src/java/org/apache/lucene/queries/CustomScoreQuery.java	(revision 1657441)
+++ lucene/queries/src/java/org/apache/lucene/queries/CustomScoreQuery.java	(working copy)
@@ -234,14 +234,14 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
-      Scorer subQueryScorer = subQueryWeight.scorer(context, acceptDocs);
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
+      Scorer subQueryScorer = subQueryWeight.scorer(context, acceptDocs, needsScores);
       if (subQueryScorer == null) {
         return null;
       }
       Scorer[] valSrcScorers = new Scorer[valSrcWeights.length];
       for(int i = 0; i < valSrcScorers.length; i++) {
-         valSrcScorers[i] = valSrcWeights[i].scorer(context, acceptDocs);
+         valSrcScorers[i] = valSrcWeights[i].scorer(context, acceptDocs, needsScores);
       }
       return new CustomScorer(CustomScoreQuery.this.getCustomScoreProvider(context), this, queryWeight, subQueryScorer, valSrcScorers);
     }
Index: lucene/queries/src/java/org/apache/lucene/queries/function/BoostedQuery.java
===================================================================
--- lucene/queries/src/java/org/apache/lucene/queries/function/BoostedQuery.java	(revision 1657441)
+++ lucene/queries/src/java/org/apache/lucene/queries/function/BoostedQuery.java	(working copy)
@@ -97,8 +97,8 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
-      Scorer subQueryScorer = qWeight.scorer(context, acceptDocs);
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
+      Scorer subQueryScorer = qWeight.scorer(context, acceptDocs, needsScores);
       if (subQueryScorer == null) {
         return null;
       }
Index: lucene/queries/src/java/org/apache/lucene/queries/function/FunctionQuery.java
===================================================================
--- lucene/queries/src/java/org/apache/lucene/queries/function/FunctionQuery.java	(revision 1657441)
+++ lucene/queries/src/java/org/apache/lucene/queries/function/FunctionQuery.java	(working copy)
@@ -89,13 +89,13 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       return new AllScorer(context, acceptDocs, this, queryWeight);
     }
 
     @Override
     public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-      return ((AllScorer)scorer(context, context.reader().getLiveDocs())).explain(doc);
+      return ((AllScorer)scorer(context, context.reader().getLiveDocs(), true)).explain(doc);
     }
   }
 
Index: lucene/queries/src/java/org/apache/lucene/queries/function/valuesource/QueryValueSource.java
===================================================================
--- lucene/queries/src/java/org/apache/lucene/queries/function/valuesource/QueryValueSource.java	(revision 1657441)
+++ lucene/queries/src/java/org/apache/lucene/queries/function/valuesource/QueryValueSource.java	(working copy)
@@ -123,7 +123,7 @@
     try {
       if (doc < lastDocRequested) {
         if (noMatches) return defVal;
-        scorer = weight.scorer(readerContext, acceptDocs);
+        scorer = weight.scorer(readerContext, acceptDocs, true);
         if (scorer==null) {
           noMatches = true;
           return defVal;
@@ -154,7 +154,7 @@
     try {
       if (doc < lastDocRequested) {
         if (noMatches) return false;
-        scorer = weight.scorer(readerContext, acceptDocs);
+        scorer = weight.scorer(readerContext, acceptDocs, true);
         scorerDoc = -1;
         if (scorer==null) {
           noMatches = true;
@@ -212,7 +212,7 @@
             mval.exists = false;
             return;
           }
-          scorer = weight.scorer(readerContext, acceptDocs);
+          scorer = weight.scorer(readerContext, acceptDocs, true);
           scorerDoc = -1;
           if (scorer==null) {
             noMatches = true;
Index: lucene/queryparser/src/test/org/apache/lucene/queryparser/surround/query/BooleanQueryTst.java
===================================================================
--- lucene/queryparser/src/test/org/apache/lucene/queryparser/surround/query/BooleanQueryTst.java	(revision 1657441)
+++ lucene/queryparser/src/test/org/apache/lucene/queryparser/surround/query/BooleanQueryTst.java	(working copy)
@@ -95,6 +95,11 @@
       }
       totalMatched++;
     }
+    
+    @Override
+    public boolean needsScores() {
+      return true;
+    }
 
     void checkNrHits() {
       Assert.assertEquals(queryText + ": nr of hits", expectedDocNrs.length, totalMatched);
Index: lucene/sandbox/src/java/org/apache/lucene/search/TermAutomatonQuery.java
===================================================================
--- lucene/sandbox/src/java/org/apache/lucene/search/TermAutomatonQuery.java	(revision 1657441)
+++ lucene/sandbox/src/java/org/apache/lucene/search/TermAutomatonQuery.java	(working copy)
@@ -385,7 +385,7 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
 
       // Initialize the enums; null for a given slot means that term didn't appear in this reader
       EnumAndScorer[] enums = new EnumAndScorer[idToTerm.size()];
Index: lucene/sandbox/src/test/org/apache/lucene/search/TestTermAutomatonQuery.java
===================================================================
--- lucene/sandbox/src/test/org/apache/lucene/search/TestTermAutomatonQuery.java	(revision 1657441)
+++ lucene/sandbox/src/test/org/apache/lucene/search/TestTermAutomatonQuery.java	(working copy)
@@ -302,6 +302,11 @@
         public void collect(int docID) throws IOException {
           assertEquals(3, scorer.freq());
         }
+        
+        @Override
+        public boolean needsScores() {
+          return true;
+        }
       });
 
     w.close();
Index: lucene/test-framework/src/java/org/apache/lucene/index/BasePostingsFormatTestCase.java
===================================================================
--- lucene/test-framework/src/java/org/apache/lucene/index/BasePostingsFormatTestCase.java	(revision 1657441)
+++ lucene/test-framework/src/java/org/apache/lucene/index/BasePostingsFormatTestCase.java	(working copy)
@@ -1457,6 +1457,29 @@
     dir.close();
   }
   
+  public void testDidntWantFreqsButAskedAnyway() throws Exception {
+    Directory dir = newDirectory();
+    IndexWriterConfig iwc = newIndexWriterConfig(new MockAnalyzer(random()));
+    iwc.setCodec(getCodec());
+    RandomIndexWriter iw = new RandomIndexWriter(random(), dir, iwc);
+    Document doc = new Document();
+    doc.add(newTextField("field", "value", Field.Store.NO));
+    iw.addDocument(doc);
+    iw.addDocument(doc);
+    DirectoryReader ir = iw.getReader();
+    LeafReader ar = getOnlySegmentReader(ir);
+    TermsEnum termsEnum = ar.terms("field").iterator(null);
+    assertTrue(termsEnum.seekExact(new BytesRef("value")));
+    DocsEnum docsEnum = termsEnum.docs(null, null, DocsEnum.FLAG_NONE);
+    assertEquals(0, docsEnum.nextDoc());
+    assertEquals(1, docsEnum.freq());
+    assertEquals(1, docsEnum.nextDoc());
+    assertEquals(1, docsEnum.freq());
+    ir.close();
+    iw.close();
+    dir.close();
+  }
+  
   // tests that ghost fields still work
   // TODO: can this be improved?
   public void testGhosts() throws Exception {
Index: lucene/test-framework/src/java/org/apache/lucene/search/AssertingWeight.java
===================================================================
--- lucene/test-framework/src/java/org/apache/lucene/search/AssertingWeight.java	(revision 1657441)
+++ lucene/test-framework/src/java/org/apache/lucene/search/AssertingWeight.java	(working copy)
@@ -58,15 +58,15 @@
   }
 
   @Override
-  public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
-    final Scorer inScorer = in.scorer(context, acceptDocs);
+  public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
+    final Scorer inScorer = in.scorer(context, acceptDocs, needsScores);
     assert inScorer == null || inScorer.docID() == -1;
     return AssertingScorer.wrap(new Random(random.nextLong()), inScorer);
   }
 
   @Override
-  public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
-    BulkScorer inScorer = in.bulkScorer(context, acceptDocs);
+  public BulkScorer bulkScorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
+    BulkScorer inScorer = in.bulkScorer(context, acceptDocs, needsScores);
     if (inScorer == null) {
       return null;
     }
Index: lucene/test-framework/src/java/org/apache/lucene/search/CheckHits.java
===================================================================
--- lucene/test-framework/src/java/org/apache/lucene/search/CheckHits.java	(revision 1657441)
+++ lucene/test-framework/src/java/org/apache/lucene/search/CheckHits.java	(working copy)
@@ -139,6 +139,11 @@
     protected void doSetNextReader(LeafReaderContext context) throws IOException {
       base = context.docBase;
     }
+    
+    @Override
+    public boolean needsScores() {
+      return false;
+    }
   }
 
   /**
@@ -507,6 +512,11 @@
     protected void doSetNextReader(LeafReaderContext context) throws IOException {
       base = context.docBase;
     }
+    
+    @Override
+    public boolean needsScores() {
+      return true;
+    }
   }
 
 }
Index: lucene/test-framework/src/java/org/apache/lucene/search/QueryUtils.java
===================================================================
--- lucene/test-framework/src/java/org/apache/lucene/search/QueryUtils.java	(revision 1657441)
+++ lucene/test-framework/src/java/org/apache/lucene/search/QueryUtils.java	(working copy)
@@ -264,7 +264,7 @@
               if (scorer == null) {
                 Weight w = s.createNormalizedWeight(q);
                 LeafReaderContext context = readerContextArray.get(leafPtr);
-                scorer = w.scorer(context, context.reader().getLiveDocs());
+                scorer = w.scorer(context, context.reader().getLiveDocs(), true);
               }
               
               int op = order[(opidx[0]++) % order.length];
@@ -302,6 +302,11 @@
           }
 
           @Override
+          public boolean needsScores() {
+            return true;
+          }
+
+          @Override
           protected void doSetNextReader(LeafReaderContext context) throws IOException {
             // confirm that skipping beyond the last doc, on the
             // previous reader, hits NO_MORE_DOCS
@@ -311,7 +316,7 @@
               indexSearcher.setSimilarity(s.getSimilarity());
               Weight w = indexSearcher.createNormalizedWeight(q);
               LeafReaderContext ctx = (LeafReaderContext)indexSearcher.getTopReaderContext();
-              Scorer scorer = w.scorer(ctx, ctx.reader().getLiveDocs());
+              Scorer scorer = w.scorer(ctx, ctx.reader().getLiveDocs(), true);
               if (scorer != null) {
                 boolean more = scorer.advance(lastDoc[0] + 1) != DocIdSetIterator.NO_MORE_DOCS;
                 Assert.assertFalse("query's last doc was "+ lastDoc[0] +" but skipTo("+(lastDoc[0]+1)+") got to "+scorer.docID(),more);
@@ -333,7 +338,7 @@
           indexSearcher.setSimilarity(s.getSimilarity());
           Weight w = indexSearcher.createNormalizedWeight(q);
           LeafReaderContext ctx = previousReader.getContext();
-          Scorer scorer = w.scorer(ctx, ctx.reader().getLiveDocs());
+          Scorer scorer = w.scorer(ctx, ctx.reader().getLiveDocs(), true);
           if (scorer != null) {
             boolean more = scorer.advance(lastDoc[0] + 1) != DocIdSetIterator.NO_MORE_DOCS;
             Assert.assertFalse("query's last doc was "+ lastDoc[0] +" but skipTo("+(lastDoc[0]+1)+") got to "+scorer.docID(),more);
@@ -364,7 +369,7 @@
           long startMS = System.currentTimeMillis();
           for (int i=lastDoc[0]+1; i<=doc; i++) {
             Weight w = s.createNormalizedWeight(q);
-            Scorer scorer = w.scorer(context.get(leafPtr), liveDocs);
+            Scorer scorer = w.scorer(context.get(leafPtr), liveDocs, true);
             Assert.assertTrue("query collected "+doc+" but skipTo("+i+") says no more docs!",scorer.advance(i) != DocIdSetIterator.NO_MORE_DOCS);
             Assert.assertEquals("query collected "+doc+" but skipTo("+i+") got to "+scorer.docID(),doc,scorer.docID());
             float skipToScore = scorer.score();
@@ -382,6 +387,11 @@
           throw new RuntimeException(e);
         }
       }
+      
+      @Override
+      public boolean needsScores() {
+        return true;
+      }
 
       @Override
       protected void doSetNextReader(LeafReaderContext context) throws IOException {
@@ -392,7 +402,7 @@
           IndexSearcher indexSearcher = LuceneTestCase.newSearcher(previousReader);
           indexSearcher.setSimilarity(s.getSimilarity());
           Weight w = indexSearcher.createNormalizedWeight(q);
-          Scorer scorer = w.scorer((LeafReaderContext)indexSearcher.getTopReaderContext(), previousReader.getLiveDocs());
+          Scorer scorer = w.scorer((LeafReaderContext)indexSearcher.getTopReaderContext(), previousReader.getLiveDocs(), true);
           if (scorer != null) {
             boolean more = scorer.advance(lastDoc[0] + 1) != DocIdSetIterator.NO_MORE_DOCS;
             Assert.assertFalse("query's last doc was "+ lastDoc[0] +" but skipTo("+(lastDoc[0]+1)+") got to "+scorer.docID(),more);
@@ -413,7 +423,7 @@
       IndexSearcher indexSearcher = LuceneTestCase.newSearcher(previousReader);
       indexSearcher.setSimilarity(s.getSimilarity());
       Weight w = indexSearcher.createNormalizedWeight(q);
-      Scorer scorer = w.scorer((LeafReaderContext)indexSearcher.getTopReaderContext(), previousReader.getLiveDocs());
+      Scorer scorer = w.scorer((LeafReaderContext)indexSearcher.getTopReaderContext(), previousReader.getLiveDocs(), true);
       if (scorer != null) {
         boolean more = scorer.advance(lastDoc[0] + 1) != DocIdSetIterator.NO_MORE_DOCS;
         Assert.assertFalse("query's last doc was "+ lastDoc[0] +" but skipTo("+(lastDoc[0]+1)+") got to "+scorer.docID(),more);
@@ -425,8 +435,8 @@
   public static void checkBulkScorerSkipTo(Random r, Query query, IndexSearcher searcher) throws IOException {
     Weight weight = searcher.createNormalizedWeight(query);
     for (LeafReaderContext context : searcher.getIndexReader().leaves()) {
-      final Scorer scorer = weight.scorer(context, context.reader().getLiveDocs());
-      final BulkScorer bulkScorer = weight.bulkScorer(context, context.reader().getLiveDocs());
+      final Scorer scorer = weight.scorer(context, context.reader().getLiveDocs(), true);
+      final BulkScorer bulkScorer = weight.bulkScorer(context, context.reader().getLiveDocs(), true);
       if (scorer == null && bulkScorer == null) {
         continue;
       }
Index: lucene/test-framework/src/java/org/apache/lucene/search/SearchEquivalenceTestBase.java
===================================================================
--- lucene/test-framework/src/java/org/apache/lucene/search/SearchEquivalenceTestBase.java	(revision 1657441)
+++ lucene/test-framework/src/java/org/apache/lucene/search/SearchEquivalenceTestBase.java	(working copy)
@@ -178,8 +178,8 @@
     }
     
     // not efficient, but simple!
-    TopDocs td1 = s1.search(q1, filter, reader.maxDoc());
-    TopDocs td2 = s2.search(q2, filter, reader.maxDoc());
+    TopDocs td1 = s1.search(q1, filter, reader.maxDoc(), random().nextBoolean() ? Sort.INDEXORDER : Sort.RELEVANCE);
+    TopDocs td2 = s2.search(q2, filter, reader.maxDoc(), random().nextBoolean() ? Sort.INDEXORDER : Sort.RELEVANCE);
     assertTrue(td1.totalHits <= td2.totalHits);
     
     // fill the superset into a bitset
Index: solr/contrib/analytics/src/java/org/apache/solr/analytics/accumulator/BasicAccumulator.java
===================================================================
--- solr/contrib/analytics/src/java/org/apache/solr/analytics/accumulator/BasicAccumulator.java	(revision 1657441)
+++ solr/contrib/analytics/src/java/org/apache/solr/analytics/accumulator/BasicAccumulator.java	(working copy)
@@ -167,4 +167,9 @@
   public long getNumQueries() {
     return 0l;
   }
+  
+  @Override
+  public boolean needsScores() {
+    return true; // TODO: is this true?
+  }
 }
Index: solr/contrib/analytics/src/java/org/apache/solr/analytics/accumulator/facet/FieldFacetAccumulator.java
===================================================================
--- solr/contrib/analytics/src/java/org/apache/solr/analytics/accumulator/facet/FieldFacetAccumulator.java	(revision 1657441)
+++ solr/contrib/analytics/src/java/org/apache/solr/analytics/accumulator/facet/FieldFacetAccumulator.java	(working copy)
@@ -146,4 +146,8 @@
   @Override
   public NamedList<?> export() { return null; }
 
+  @Override
+  public boolean needsScores() {
+    return true; // TODO: is this true?
+  }
 }
Index: solr/contrib/analytics/src/java/org/apache/solr/analytics/accumulator/facet/QueryFacetAccumulator.java
===================================================================
--- solr/contrib/analytics/src/java/org/apache/solr/analytics/accumulator/facet/QueryFacetAccumulator.java	(revision 1657441)
+++ solr/contrib/analytics/src/java/org/apache/solr/analytics/accumulator/facet/QueryFacetAccumulator.java	(working copy)
@@ -66,4 +66,8 @@
     return null;
   }
 
+  @Override
+  public boolean needsScores() {
+    return true; // TODO: is this true?
+  }
 }
Index: solr/core/src/java/org/apache/solr/handler/component/ExpandComponent.java
===================================================================
--- solr/core/src/java/org/apache/solr/handler/component/ExpandComponent.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/handler/component/ExpandComponent.java	(working copy)
@@ -510,6 +510,11 @@
       }
     }
 
+    @Override
+    public boolean needsScores() {
+      return true; // TODO: is this always true?
+    }
+
     public LeafCollector getLeafCollector(LeafReaderContext context) throws IOException {
       final int docBase = context.docBase;
 
@@ -581,6 +586,11 @@
       this.field = field;
       this.collapsedSet = collapsedSet;
     }
+    
+    @Override
+    public boolean needsScores() {
+      return true; // TODO: is this always true?
+    }
 
     public LeafCollector getLeafCollector(LeafReaderContext context) throws IOException {
       final int docBase = context.docBase;
Index: solr/core/src/java/org/apache/solr/schema/LatLonType.java
===================================================================
--- solr/core/src/java/org/apache/solr/schema/LatLonType.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/schema/LatLonType.java	(working copy)
@@ -343,13 +343,13 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       return new SpatialScorer(context, acceptDocs, this, queryWeight);
     }
 
     @Override
     public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-      return ((SpatialScorer)scorer(context, context.reader().getLiveDocs())).explain(doc);
+      return ((SpatialScorer)scorer(context, context.reader().getLiveDocs(), true)).explain(doc);
     }
   }
 
Index: solr/core/src/java/org/apache/solr/search/DelegatingCollector.java
===================================================================
--- solr/core/src/java/org/apache/solr/search/DelegatingCollector.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/search/DelegatingCollector.java	(working copy)
@@ -64,6 +64,11 @@
   }
 
   @Override
+  public boolean needsScores() {
+    return delegate.needsScores();
+  }
+
+  @Override
   public void collect(int doc) throws IOException {
     leafDelegate.collect(doc);
   }
Index: solr/core/src/java/org/apache/solr/search/DocSetCollector.java
===================================================================
--- solr/core/src/java/org/apache/solr/search/DocSetCollector.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/search/DocSetCollector.java	(working copy)
@@ -84,6 +84,11 @@
   }
 
   @Override
+  public boolean needsScores() {
+    return false;
+  }
+
+  @Override
   protected void doSetNextReader(LeafReaderContext context) throws IOException {
     this.base = context.docBase;
   }
Index: solr/core/src/java/org/apache/solr/search/ExportQParserPlugin.java
===================================================================
--- solr/core/src/java/org/apache/solr/search/ExportQParserPlugin.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/search/ExportQParserPlugin.java	(working copy)
@@ -174,5 +174,9 @@
       return new TopDocs(totalHits, scoreDocs, 0.0f);
     }
 
+    @Override
+    public boolean needsScores() {
+      return true; // TODO: is this the case?
+    }
   }
 }
\ No newline at end of file
Index: solr/core/src/java/org/apache/solr/search/JoinQParserPlugin.java
===================================================================
--- solr/core/src/java/org/apache/solr/search/JoinQParserPlugin.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/search/JoinQParserPlugin.java	(working copy)
@@ -304,7 +304,7 @@
 
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       if (filter == null) {
         boolean debug = rb != null && rb.isDebug();
         long start = debug ? System.currentTimeMillis() : 0;
@@ -573,7 +573,7 @@
 
     @Override
     public Explanation explain(LeafReaderContext context, int doc) throws IOException {
-      Scorer scorer = scorer(context, context.reader().getLiveDocs());
+      Scorer scorer = scorer(context, context.reader().getLiveDocs(), true);
       boolean exists = scorer.advance(doc) == doc;
 
       ComplexExplanation result = new ComplexExplanation();
Index: solr/core/src/java/org/apache/solr/search/ReRankQParserPlugin.java
===================================================================
--- solr/core/src/java/org/apache/solr/search/ReRankQParserPlugin.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/search/ReRankQParserPlugin.java	(working copy)
@@ -196,8 +196,8 @@
       return mainWeight.getValueForNormalization();
     }
 
-    public Scorer scorer(LeafReaderContext context, Bits bits) throws IOException {
-      return mainWeight.scorer(context, bits);
+    public Scorer scorer(LeafReaderContext context, Bits bits, boolean needsScores) throws IOException {
+      return mainWeight.scorer(context, bits, needsScores);
     }
 
     public Query getQuery() {
@@ -266,6 +266,11 @@
       return mainCollector.getLeafCollector(context);
     }
 
+    @Override
+    public boolean needsScores() {
+      return true;
+    }
+
     public TopDocs topDocs(int start, int howMany) {
 
       try {
Index: solr/core/src/java/org/apache/solr/search/SolrConstantScoreQuery.java
===================================================================
--- solr/core/src/java/org/apache/solr/search/SolrConstantScoreQuery.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/search/SolrConstantScoreQuery.java	(working copy)
@@ -119,7 +119,7 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
       return new ConstantScorer(context, this, queryWeight, acceptDocs);
     }
 
Index: solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java
===================================================================
--- solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java	(working copy)
@@ -1641,6 +1641,11 @@
           public void collect(int doc) {
             numHits[0]++;
           }
+          
+          @Override
+          public boolean needsScores() {
+            return false;
+          }
         };
       } else {
         collector = new SimpleCollector() {
@@ -1655,6 +1660,11 @@
             float score = scorer.score();
             if (score > topscore[0]) topscore[0]=score;            
           }
+          
+          @Override
+          public boolean needsScores() {
+            return true;
+          }
         };
       }
       
@@ -1739,6 +1749,11 @@
             float score = scorer.score();
             if (score > topscore[0]) topscore[0] = score;
           }
+          
+          @Override
+          public boolean needsScores() {
+            return true;
+          }
         };
         
         collector = MultiCollector.wrap(setCollector, topScoreCollector);
@@ -2489,7 +2504,7 @@
         iterators.add(iter);
       }
       for (Weight w : weights) {
-        Scorer scorer = w.scorer(context, context.reader().getLiveDocs());
+        Scorer scorer = w.scorer(context, context.reader().getLiveDocs(), true);
         if (scorer == null) return null;
         iterators.add(scorer);
       }
Index: solr/core/src/java/org/apache/solr/search/join/IgnoreAcceptDocsQuery.java
===================================================================
--- solr/core/src/java/org/apache/solr/search/join/IgnoreAcceptDocsQuery.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/search/join/IgnoreAcceptDocsQuery.java	(working copy)
@@ -86,8 +86,8 @@
     }
 
     @Override
-    public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
-      return w.scorer(context, null);
+    public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
+      return w.scorer(context, null, needsScores);
     }
   }
 
Index: solr/core/src/java/org/apache/solr/update/DeleteByQueryWrapper.java
===================================================================
--- solr/core/src/java/org/apache/solr/update/DeleteByQueryWrapper.java	(revision 1657441)
+++ solr/core/src/java/org/apache/solr/update/DeleteByQueryWrapper.java	(working copy)
@@ -82,8 +82,8 @@
       public void normalize(float norm, float topLevelBoost) { inner.normalize(norm, topLevelBoost); }
 
       @Override
-      public Scorer scorer(LeafReaderContext context, Bits acceptDocs) throws IOException {
-        return inner.scorer(privateContext.getIndexReader().leaves().get(0), acceptDocs);
+      public Scorer scorer(LeafReaderContext context, Bits acceptDocs, boolean needsScores) throws IOException {
+        return inner.scorer(privateContext.getIndexReader().leaves().get(0), acceptDocs, needsScores);
       }
     };
   }
Index: solr/core/src/test/org/apache/solr/search/TestRankQueryPlugin.java
===================================================================
--- solr/core/src/test/org/apache/solr/search/TestRankQueryPlugin.java	(revision 1657441)
+++ solr/core/src/test/org/apache/solr/search/TestRankQueryPlugin.java	(working copy)
@@ -760,6 +760,11 @@
     public int getTotalHits() {
       return list.size();
     }
+    
+    @Override
+    public boolean needsScores() {
+      return true;
+    }
   }
 
   class TestCollector1 extends TopDocsCollector {
@@ -817,6 +822,11 @@
     public int getTotalHits() {
       return list.size();
     }
+    
+    @Override
+    public boolean needsScores() {
+      return true;
+    }
   }
 
 }