From 453dc17567088860de4db9400330b49925423b81 Mon Sep 17 00:00:00 2001
From: Michael McCandless <mikemccand@apache.org>
Date: Tue, 27 Oct 2015 14:37:10 +0000
Subject: [PATCH] LUCENE-6825: don't NPE when trying to merge a segment that
 has no documents that indexed dimensional values

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1710830 13f79535-47bb-0310-9956-ffa450edef68
---
 .../src/java/org/apache/lucene/codecs/DimensionalWriter.java  | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lucene/core/src/java/org/apache/lucene/codecs/DimensionalWriter.java b/lucene/core/src/java/org/apache/lucene/codecs/DimensionalWriter.java
index b236b5163f7..dc86ab2777d 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/DimensionalWriter.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/DimensionalWriter.java
@@ -51,6 +51,10 @@ public abstract class DimensionalWriter implements Closeable {
                        }
                        for (int i=0;i<mergeState.dimensionalReaders.length;i++) {
                          DimensionalReader dimensionalReader = mergeState.dimensionalReaders[i];
+                         if (dimensionalReader == null) {
+                           // This segment has no dimensional values
+                           continue;
+                         }
                          MergeState.DocMap docMap = mergeState.docMaps[i];
                          int docBase = mergeState.docBase[i];
                          dimensionalReader.intersect(fieldInfo.name,