From a14972d7ae2357ab7150909332a04c9a1a94474c Mon Sep 17 00:00:00 2001
From: Simon Willnauer <simonw@apache.org>
Date: Tue, 21 Nov 2017 14:22:31 +0100
Subject: [PATCH] LUCENE-8055: MemoryIndex.MemoryDocValuesIterator returns 2
 documents instead of 1

Fixes a bug if there is a DV field in the MemoryIndex the
`MemoryIndex.MemoryDocValuesIterator` will return 2 documents instead of 1.
---
 lucene/CHANGES.txt                                          | 5 +++++
 .../java/org/apache/lucene/index/memory/MemoryIndex.java    | 2 +-
 .../org/apache/lucene/index/memory/TestMemoryIndex.java     | 6 ++++++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index 40b39c97fde..d7fd0c37c05 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -114,6 +114,11 @@ Tests
 
 ======================= Lucene 7.1.1 =======================
 
+Bug Fixes
+
+* LUCENE-8055: MemoryIndex.MemoryDocValuesIterator returns 2 documents 
+  instead of 1. (Simon Willnauer)
+
 Build
 
 * LUCENE-6144: Upgrade Ivy to 2.4.0; 'ant ivy-bootstrap' now removes old Ivy
diff --git a/lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java b/lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java
index fa6b564ea4c..f732cf3916b 100644
--- a/lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java
+++ b/lucene/memory/src/java/org/apache/lucene/index/memory/MemoryIndex.java
@@ -929,7 +929,7 @@ public class MemoryIndex {
     }
 
     int docId() {
-      return doc > 1 ? NumericDocValues.NO_MORE_DOCS : doc;
+      return doc > 0 ? NumericDocValues.NO_MORE_DOCS : doc;
     }
 
   }
diff --git a/lucene/memory/src/test/org/apache/lucene/index/memory/TestMemoryIndex.java b/lucene/memory/src/test/org/apache/lucene/index/memory/TestMemoryIndex.java
index a737aad834e..a4b9d71e545 100644
--- a/lucene/memory/src/test/org/apache/lucene/index/memory/TestMemoryIndex.java
+++ b/lucene/memory/src/test/org/apache/lucene/index/memory/TestMemoryIndex.java
@@ -59,6 +59,7 @@ import org.apache.lucene.index.SortedSetDocValues;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.index.TermsEnum;
 import org.apache.lucene.search.CollectionStatistics;
+import org.apache.lucene.search.DocIdSetIterator;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.MatchAllDocsQuery;
 import org.apache.lucene.search.PhraseQuery;
@@ -274,6 +275,7 @@ public class TestMemoryIndex extends LuceneTestCase {
     NumericDocValues numericDocValues = leafReader.getNumericDocValues("numeric");
     assertEquals(0, numericDocValues.nextDoc());
     assertEquals(29L, numericDocValues.longValue());
+    assertEquals(DocIdSetIterator.NO_MORE_DOCS, numericDocValues.nextDoc());
     SortedNumericDocValues sortedNumericDocValues = leafReader.getSortedNumericDocValues("sorted_numeric");
     assertEquals(0, sortedNumericDocValues.nextDoc());
     assertEquals(5, sortedNumericDocValues.docValueCount());
@@ -282,14 +284,17 @@ public class TestMemoryIndex extends LuceneTestCase {
     assertEquals(32L, sortedNumericDocValues.nextValue());
     assertEquals(32L, sortedNumericDocValues.nextValue());
     assertEquals(33L, sortedNumericDocValues.nextValue());
+    assertEquals(DocIdSetIterator.NO_MORE_DOCS, sortedNumericDocValues.nextDoc());
     BinaryDocValues binaryDocValues = leafReader.getBinaryDocValues("binary");
     assertEquals(0, binaryDocValues.nextDoc());
     assertEquals("a", binaryDocValues.binaryValue().utf8ToString());
+    assertEquals(DocIdSetIterator.NO_MORE_DOCS, binaryDocValues.nextDoc());
     SortedDocValues sortedDocValues = leafReader.getSortedDocValues("sorted");
     assertEquals(0, sortedDocValues.nextDoc());
     assertEquals("b", sortedDocValues.binaryValue().utf8ToString());
     assertEquals(0, sortedDocValues.ordValue());
     assertEquals("b", sortedDocValues.lookupOrd(0).utf8ToString());
+    assertEquals(DocIdSetIterator.NO_MORE_DOCS, sortedDocValues.nextDoc());
     SortedSetDocValues sortedSetDocValues = leafReader.getSortedSetDocValues("sorted_set");
     assertEquals(3, sortedSetDocValues.getValueCount());
     assertEquals(0, sortedSetDocValues.nextDoc());
@@ -300,6 +305,7 @@ public class TestMemoryIndex extends LuceneTestCase {
     assertEquals("c", sortedSetDocValues.lookupOrd(0L).utf8ToString());
     assertEquals("d", sortedSetDocValues.lookupOrd(1L).utf8ToString());
     assertEquals("f", sortedSetDocValues.lookupOrd(2L).utf8ToString());
+    assertEquals(DocIdSetIterator.NO_MORE_DOCS, sortedDocValues.nextDoc());
   }
 
   public void testDocValues_resetIterator() throws Exception {