From 064e8dc60ab6955caa692d7528ab7c85b8ed0bf8 Mon Sep 17 00:00:00 2001
From: Simon Willnauer <simonw@apache.org>
Date: Wed, 8 Dec 2010 02:02:02 +0000
Subject: [PATCH] LUCENE-2802: NRT DirectoryReader returned incorrect values
 from getVersion, isOptimized, getCommitUserData, getIndexCommit and isCurrent
 due to a mutable reference to the IndexWriters SegmentInfos

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1043277 13f79535-47bb-0310-9956-ffa450edef68
---
 lucene/CHANGES.txt                            |  5 +++
 .../apache/lucene/index/DirectoryReader.java  |  9 ++---
 .../lucene/index/TestIndexWriterReader.java   | 38 +++++++++++++++++++
 3 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index 49d9acd491b..17852b48009 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -348,6 +348,11 @@ Bug fixes
   with more document deletions is requested before a reader with fewer
   deletions, provided they share some segments. (yonik)
 
+* LUCENE-2802: NRT DirectoryReader returned incorrect values from
+  getVersion, isOptimized, getCommitUserData, getIndexCommit and isCurrent due
+  to a mutable reference to the IndexWriters SegmentInfos. 
+  (Simon Willnauer, Earwin Burrfoot)
+
 
 
 ======================= Lucene 3.x (not yet released) =======================
diff --git a/lucene/src/java/org/apache/lucene/index/DirectoryReader.java b/lucene/src/java/org/apache/lucene/index/DirectoryReader.java
index c4de527bd1c..d3949b4fe53 100644
--- a/lucene/src/java/org/apache/lucene/index/DirectoryReader.java
+++ b/lucene/src/java/org/apache/lucene/index/DirectoryReader.java
@@ -55,8 +55,7 @@ class DirectoryReader extends IndexReader implements Cloneable {
 
   private IndexDeletionPolicy deletionPolicy;
   private Lock writeLock;
-  private SegmentInfos segmentInfos;
-  private SegmentInfos segmentInfosStart;
+  private final SegmentInfos segmentInfos;
   private boolean stale;
   private final int termInfosIndexDivisor;
 
@@ -106,7 +105,6 @@ class DirectoryReader extends IndexReader implements Cloneable {
     this.segmentInfos = sis;
     this.deletionPolicy = deletionPolicy;
     this.termInfosIndexDivisor = termInfosIndexDivisor;
-
     if (codecs == null) {
       this.codecs = CodecProvider.getDefault();
     } else {
@@ -145,8 +143,7 @@ class DirectoryReader extends IndexReader implements Cloneable {
   DirectoryReader(IndexWriter writer, SegmentInfos infos, int termInfosIndexDivisor, CodecProvider codecs) throws IOException {
     this.directory = writer.getDirectory();
     this.readOnly = true;
-    segmentInfos = infos;
-    segmentInfosStart = (SegmentInfos) infos.clone();
+    segmentInfos = (SegmentInfos) infos.clone();// make sure we clone otherwise we share mutable state with IW
     this.termInfosIndexDivisor = termInfosIndexDivisor;
     if (codecs == null) {
       this.codecs = CodecProvider.getDefault();
@@ -860,7 +857,7 @@ class DirectoryReader extends IndexReader implements Cloneable {
       // we loaded SegmentInfos from the directory
       return SegmentInfos.readCurrentVersion(directory, codecs) == segmentInfos.getVersion();
     } else {
-      return writer.nrtIsCurrent(segmentInfosStart);
+      return writer.nrtIsCurrent(segmentInfos);
     }
   }
 
diff --git a/lucene/src/test/org/apache/lucene/index/TestIndexWriterReader.java b/lucene/src/test/org/apache/lucene/index/TestIndexWriterReader.java
index 7704a599902..5c357927e33 100644
--- a/lucene/src/test/org/apache/lucene/index/TestIndexWriterReader.java
+++ b/lucene/src/test/org/apache/lucene/index/TestIndexWriterReader.java
@@ -175,6 +175,44 @@ public class TestIndexWriterReader extends LuceneTestCase {
     dir1.close();
   }
   
+  public void testIsCurrent() throws IOException {
+    Directory dir = newDirectory();
+    IndexWriterConfig iwc = newIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer());
+    
+    IndexWriter writer = new IndexWriter(dir, iwc);
+    Document doc = new Document();
+    doc.add(newField("field", "a b c", Field.Store.NO, Field.Index.ANALYZED));
+    writer.addDocument(doc);
+    writer.close();
+    
+    iwc = newIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer());
+    writer = new IndexWriter(dir, iwc);
+    doc = new Document();
+    doc.add(newField("field", "a b c", Field.Store.NO, Field.Index.ANALYZED));
+    IndexReader nrtReader = writer.getReader();
+    assertTrue(nrtReader.isCurrent());
+    writer.addDocument(doc);
+    assertFalse(nrtReader.isCurrent()); // should see the changes
+    writer.optimize(); // make sure we don't have a merge going on
+    assertFalse(nrtReader.isCurrent());
+    nrtReader.close();
+    
+    IndexReader dirReader = IndexReader.open(dir);
+    nrtReader = writer.getReader();
+    
+    assertTrue(dirReader.isCurrent());
+    assertTrue(nrtReader.isCurrent()); // nothing was committed yet so we are still current
+    assertEquals(2, nrtReader.maxDoc()); // sees the actual document added
+    assertEquals(1, dirReader.maxDoc());
+    writer.close(); // close is actually a commit both should see the changes
+    assertTrue(nrtReader.isCurrent()); 
+    assertFalse(dirReader.isCurrent()); // this reader has been opened before the writer was closed / committed
+    
+    dirReader.close();
+    nrtReader.close();
+    dir.close();
+  }
+  
   /**
    * Test using IW.addIndexes
    *