From 9adff2072a2bc4f0c23a7108816d83bfc8f3e3a0 Mon Sep 17 00:00:00 2001
From: Michael Busch <buschmi@apache.org>
Date: Thu, 7 Feb 2008 22:46:37 +0000
Subject: [PATCH] LUCENE-1169: Fixed bug in IndexSearcher.search(): searching
 with a filter might miss some hits because scorer.skipTo() is called without
 checking if the scorer is already at the right position.

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@619676 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                   |  6 ++
 .../apache/lucene/search/IndexSearcher.java   |  8 +-
 .../lucene/search/TestFilteredSearch.java     | 93 +++++++++++++++++++
 3 files changed, 104 insertions(+), 3 deletions(-)
 create mode 100644 src/test/org/apache/lucene/search/TestFilteredSearch.java

diff --git a/CHANGES.txt b/CHANGES.txt
index 841c05667f3..4221dcdc1c1 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -49,6 +49,12 @@ Bug fixes
     documents have mixed term vectors (Suresh Guvvala via Mike
     McCandless).
 	
+ 4. LUCENE-1169: Fixed bug in IndexSearcher.search(): searching with
+    a filter might miss some hits because scorer.skipTo() is called
+    without checking if the scorer is already at the right position.
+    scorer.skipTo(scorer.doc()) is not a NOOP, it behaves as 
+    scorer.next(). (Eks Dev, Michael Busch)
+	
 New features
 
  1. LUCENE-1137: Added Token.set/getFlags() accessors for passing more information about a Token through the analysis
diff --git a/src/java/org/apache/lucene/search/IndexSearcher.java b/src/java/org/apache/lucene/search/IndexSearcher.java
index cb9ef692355..eecd8b20a01 100644
--- a/src/java/org/apache/lucene/search/IndexSearcher.java
+++ b/src/java/org/apache/lucene/search/IndexSearcher.java
@@ -139,16 +139,18 @@ public class IndexSearcher extends Searcher {
     }
 
     DocIdSetIterator docIdSetIterator = filter.getDocIdSet(reader).iterator(); // CHECKME: use ConjunctionScorer here?
-    boolean more = docIdSetIterator.next();
+    
+    boolean more = docIdSetIterator.next() && scorer.skipTo(docIdSetIterator.doc());
+
     while (more) {
       int filterDocId = docIdSetIterator.doc();
-      if (! scorer.skipTo(filterDocId)) {
+      if (filterDocId > scorer.doc() && !scorer.skipTo(filterDocId)) {
         more = false;
       } else {
         int scorerDocId = scorer.doc();
         if (scorerDocId == filterDocId) { // permitted by filter
           results.collect(scorerDocId, scorer.score());
-          more = docIdSetIterator.skipTo(scorerDocId + 1);
+          more = docIdSetIterator.next();
         } else {
           more = docIdSetIterator.skipTo(scorerDocId);
         }
diff --git a/src/test/org/apache/lucene/search/TestFilteredSearch.java b/src/test/org/apache/lucene/search/TestFilteredSearch.java
new file mode 100644
index 00000000000..534a9d3fb59
--- /dev/null
+++ b/src/test/org/apache/lucene/search/TestFilteredSearch.java
@@ -0,0 +1,93 @@
+/**
+ * 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.
+ */
+
+package org.apache.lucene.search;
+
+import java.io.IOException;
+
+import junit.framework.TestCase;
+
+import org.apache.lucene.analysis.WhitespaceAnalyzer;
+import org.apache.lucene.document.Document;
+import org.apache.lucene.document.Field;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.IndexWriter;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.store.RAMDirectory;
+import org.apache.lucene.util.OpenBitSet;
+
+
+/**
+ *
+ */
+public class TestFilteredSearch extends TestCase
+{
+
+  public TestFilteredSearch(String name) {
+    super(name);
+  }
+
+  private static final String FIELD = "category";
+  
+  public void testFilteredSearch() {
+    RAMDirectory directory = new RAMDirectory();
+    int[] filterBits = {1, 36};
+    Filter filter = new SimpleDocIdSetFilter(filterBits);
+    
+
+    try {
+      IndexWriter writer = new IndexWriter(directory, new WhitespaceAnalyzer(), true, IndexWriter.MaxFieldLength.LIMITED);
+      for (int i = 0; i < 60; i++) {//Simple docs
+        Document doc = new Document();
+        doc.add(new Field(FIELD, Integer.toString(i), Field.Store.YES, Field.Index.UN_TOKENIZED));
+        writer.addDocument(doc);
+      }
+      writer.close();
+
+      BooleanQuery booleanQuery = new BooleanQuery();
+      booleanQuery.add(new TermQuery(new Term(FIELD, "36")), BooleanClause.Occur.SHOULD);
+     
+     
+      IndexSearcher indexSearcher = new IndexSearcher(directory);
+      org.apache.lucene.search.Hits hits = indexSearcher.search(booleanQuery, filter);
+      assertEquals("Number of matched documents", 1, hits.length());
+
+    }
+    catch (IOException e) {
+      fail(e.getMessage());
+    }
+
+  }
+  
+
+  public static final class SimpleDocIdSetFilter extends Filter {
+    private OpenBitSet bits;
+
+    public SimpleDocIdSetFilter(int[] docs) {
+      bits = new OpenBitSet();
+      for(int i = 0; i < docs.length; i++){
+    	  bits.set(docs[i]);
+      }
+      
+    }
+
+    public DocIdSet getDocIdSet(IndexReader reader) {
+      return bits;
+    }
+  }
+
+}