docs/attachments/LUCENE-5784/common_terms.patch

diff --git a/lucene/queries/src/java/org/apache/lucene/queries/CommonTermsQuery.java b/lucene/queries/src/java/org/apache/lucene/queries/CommonTermsQuery.java
index a78cef3..0099404 100644
--- a/lucene/queries/src/java/org/apache/lucene/queries/CommonTermsQuery.java
+++ b/lucene/queries/src/java/org/apache/lucene/queries/CommonTermsQuery.java
@@ -227,6 +227,9 @@ public class CommonTermsQuery extends Query {
       return lowFreq;
     } else {
       query.add(highFreq, Occur.SHOULD);
+      if (highFreqOccur == Occur.MUST) {
+        query.setMinimumNumberShouldMatch(1);
+      }
       query.add(lowFreq, Occur.MUST);
       query.setBoost(getBoost());
       return query;
diff --git a/lucene/queries/src/test/org/apache/lucene/queries/CommonTermsQueryTest.java b/lucene/queries/src/test/org/apache/lucene/queries/CommonTermsQueryTest.java
index 3cb8deb..de07ac6 100644
--- a/lucene/queries/src/test/org/apache/lucene/queries/CommonTermsQueryTest.java
+++ b/lucene/queries/src/test/org/apache/lucene/queries/CommonTermsQueryTest.java
@@ -61,9 +61,9 @@ public class CommonTermsQueryTest extends LuceneTestCase {
     Directory dir = newDirectory();
     MockAnalyzer analyzer = new MockAnalyzer(random());
     RandomIndexWriter w = new RandomIndexWriter(random(), dir, analyzer);
-    String[] docs = new String[] {"this is the end of the world right",
+    String[] docs = new String[] {"this is not the end of the world right",
         "is this it or maybe not",
-        "this is the end of the universe as we know it",
+        "this is not the end of the universe as we know it",
         "there is the famous restaurant at the end of the universe",};
     for (int i = 0; i < docs.length; i++) {
       Document doc = new Document();
@@ -124,8 +124,21 @@ public class CommonTermsQueryTest extends LuceneTestCase {
       TopDocs search = s.search(query, 10);
       assertEquals(search.totalHits, 1);
       assertEquals("3", r.document(search.scoreDocs[0].doc).get("id"));
-      
     }
+
+    { // low and high freq are mandatory
+      CommonTermsQuery query = new CommonTermsQuery(Occur.MUST, Occur.MUST,
+          random().nextBoolean() ? 2.0f : 0.5f);
+      query.add(new Term("field", "is"));
+      query.add(new Term("field", "this"));
+      query.add(new Term("field", "not"));
+      query.add(new Term("field", "universe"));
+
+      TopDocs search = s.search(query, 10);
+      assertEquals(search.totalHits, 1);
+      assertEquals("2", r.document(search.scoreDocs[0].doc).get("id"));
+    }
+
     r.close();
     w.shutdown();
     dir.close();