SOLR-5561: Fix implicit DefaultSimilarityFactory initialization in IndexSchema to properly specify discountOverlap option

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1566842 13f79535-47bb-0310-9956-ffa450edef68

solr/CHANGES.txt

@@ -71,6 +71,13 @@ Upgrading from Solr 4.6.0
 
 * CloudSolrServer and LBHttpSolrServer no longer declare MalformedURLException
   as thrown from their constructors.  
+
+* Due to a bug in previous versions the default value of the 'discountOverlap' property
+  of DefaultSimilarity was not being set appropriately if you were using the implicit
+  DefaultSimilarityFactory instead of explicitly configuring it.  To preserve 
+  consistent behavior for people who upgrade, the implicit behavior is now contingent 
+  on the <luceneMatchVersion/> -- discountOverlap=false for 4.6 and below, 
+  discountOverlap=true for 4.7 and above.  See SOLR-5561 for more information.
                       
 Detailed Change List
 ----------------------
@@ -305,6 +312,10 @@ Bug Fixes
 * SOLR-5709: Highlighting grouped duplicate docs from different shards with
   group.limit > 1 throws ArrayIndexOutOfBoundsException. (Steve Rowe)
 
+* SOLR-5561: Fix implicit DefaultSimilarityFactory initialization in IndexSchema 
+  to properly specify discountOverlap option.
+  (Isaac Hebsh, Ahmet Arslan, Vitaliy Zhovtyuk, hossman)
+
 Optimizations
 ----------------------
 

solr/core/src/java/org/apache/solr/schema/IndexSchema.java

@@ -477,6 +477,12 @@ public class IndexSchema {
       similarityFactory = readSimilarity(loader, node);
       if (similarityFactory == null) {
         similarityFactory = new DefaultSimilarityFactory();
+        final NamedList similarityParams = new NamedList();
+        Version luceneVersion = getDefaultLuceneMatchVersion();
+        if (!luceneVersion.onOrAfter(Version.LUCENE_47)) {
+          similarityParams.add(DefaultSimilarityFactory.DISCOUNT_OVERLAPS, false);
+        }
+        similarityFactory.init(SolrParams.toSolrParams(similarityParams));
       } else {
         isExplicitSimilarity = true;
       }

solr/core/src/java/org/apache/solr/search/similarities/DefaultSimilarityFactory.java

@@ -38,12 +38,22 @@ import org.apache.solr.schema.SimilarityFactory;
  * @lucene.experimental
  */
 public class DefaultSimilarityFactory extends SimilarityFactory {
-  protected boolean discountOverlaps;
+
+  /** Init param name for specifying the value to use in 
+   * {@link DefaultSimilarity#setDiscountOverlaps(boolean)} 
+   */
+  public static final String DISCOUNT_OVERLAPS = "discountOverlaps";
+
+  /** 
+   * Controls the value of {@link DefaultSimilarity#setDiscountOverlaps(boolean)} 
+   * on newly constructed instances of {@link DefaultSimilarity}
+   */
+  protected boolean discountOverlaps = true;
 
   @Override
   public void init(SolrParams params) {
     super.init(params);
-    discountOverlaps = params.getBool("discountOverlaps", true);
+    discountOverlaps = params.getBool(DISCOUNT_OVERLAPS, true);
   }
 
   @Override

solr/core/src/test/org/apache/solr/search/similarities/TestNonDefinedSimilarityFactory.java

@@ -0,0 +1,59 @@
+package org.apache.solr.search.similarities;
+
+/*
+ * 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 org.apache.lucene.search.similarities.DefaultSimilarity;
+import org.apache.lucene.search.similarities.Similarity;
+import org.apache.lucene.util.Version;
+import org.junit.After;
+
+/**
+ * Verifies that the default behavior of the implicit {@link DefaultSimilarityFactory} 
+ * (ie: no similarity configured in schema.xml at all) is consistnent with 
+ * expectations based on the luceneMatchVersion
+ * @see <a href="https://issues.apache.org/jira/browse/SOLR-5561">SOLR-5561</a>
+ */
+public class TestNonDefinedSimilarityFactory extends BaseSimilarityTestCase {
+
+  @After
+  public void cleanup() throws Exception {
+    deleteCore();
+  }
+
+  public void testCurrent() throws Exception {
+    // no sys prop set, rely on LUCENE_CURRENT
+    initCore("solrconfig-basic.xml","schema-tiny.xml");
+    DefaultSimilarity sim = getSimilarity("text", DefaultSimilarity.class);
+    assertEquals(true, sim.getDiscountOverlaps());
+  }
+
+  public void test47() throws Exception {
+    System.setProperty("tests.luceneMatchVersion", Version.LUCENE_47.toString());
+    initCore("solrconfig-basic.xml","schema-tiny.xml");
+    DefaultSimilarity sim = getSimilarity("text", DefaultSimilarity.class);
+    assertEquals(true, sim.getDiscountOverlaps());
+  }
+
+  public void test46() throws Exception {
+    System.setProperty("tests.luceneMatchVersion", Version.LUCENE_46.toString());
+    initCore("solrconfig-basic.xml","schema-tiny.xml");
+    DefaultSimilarity sim = getSimilarity("text", DefaultSimilarity.class);
+    assertEquals(false, sim.getDiscountOverlaps());
+  }
+
+}