From f485798685eacd3d67ca30358803f9879d00a73b Mon Sep 17 00:00:00 2001
From: Uwe Schindler <uschindler@apache.org>
Date: Tue, 15 Jan 2013 21:16:49 +0000
Subject: [PATCH] LUCENE-4465: Let ConstantScoreQuery's Scorer return its child
 scorer.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1433652 13f79535-47bb-0310-9956-ffa450edef68
---
 lucene/CHANGES.txt                                     |  3 +++
 .../org/apache/lucene/search/ConstantScoreQuery.java   | 10 ++++++++++
 2 files changed, 13 insertions(+)

diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index 08d06e4c9b2..2080d4d725e 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -352,6 +352,9 @@ Bug Fixes
   DEFAULT_ARTICLES list passed to ElisionFilter.  (David Leunen via Steve Rowe)
 
 * LUCENE-4671: Fix CharsRef.subSequence method.  (Tim Smith via Robert Muir)
+
+* LUCENE-4465: Let ConstantScoreQuery's Scorer return its child scorer.
+  (selckin via Uwe Schindler)
     
 Changes in Runtime Behavior
   
diff --git a/lucene/core/src/java/org/apache/lucene/search/ConstantScoreQuery.java b/lucene/core/src/java/org/apache/lucene/search/ConstantScoreQuery.java
index 71add6d0b48..f6fd987b979 100644
--- a/lucene/core/src/java/org/apache/lucene/search/ConstantScoreQuery.java
+++ b/lucene/core/src/java/org/apache/lucene/search/ConstantScoreQuery.java
@@ -24,6 +24,8 @@ import org.apache.lucene.util.Bits;
 import org.apache.lucene.util.ToStringUtils;
 
 import java.io.IOException;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Set;
 
 /**
@@ -248,6 +250,14 @@ public class ConstantScoreQuery extends Query {
         return super.score(collector, max, firstDocID);
       }
     }
+
+    @Override
+    public Collection<ChildScorer> getChildren() {
+      if (docIdSetIterator instanceof Scorer)
+        return Collections.singletonList(new ChildScorer((Scorer) docIdSetIterator, "constant"));
+      else
+        return Collections.emptyList();
+    }
   }
 
   @Override