From ff1df8a15c6eaed81ad7c033014a173175383e5d Mon Sep 17 00:00:00 2001
From: Simon Willnauer <simonw@apache.org>
Date: Wed, 7 Nov 2018 20:20:42 +0100
Subject: [PATCH] LUCENE-8558: Replace O(n) lookup with O(1) lookup in
 PerFieldMergeState#FilterFieldInfos

---
 .../org/apache/lucene/codecs/perfield/PerFieldMergeState.java   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lucene/core/src/java/org/apache/lucene/codecs/perfield/PerFieldMergeState.java b/lucene/core/src/java/org/apache/lucene/codecs/perfield/PerFieldMergeState.java
index 291a384608d..99a04da0422 100644
--- a/lucene/core/src/java/org/apache/lucene/codecs/perfield/PerFieldMergeState.java
+++ b/lucene/core/src/java/org/apache/lucene/codecs/perfield/PerFieldMergeState.java
@@ -125,7 +125,7 @@ final class PerFieldMergeState {
       this.filteredNames = new HashSet<>(filterFields);
       this.filtered = new ArrayList<>(filterFields.size());
       for (FieldInfo fi : src) {
-        if (filterFields.contains(fi.name)) {
+        if (this.filteredNames.contains(fi.name)) {
           this.filtered.add(fi);
           hasVectors |= fi.hasVectors();
           hasProx |= fi.getIndexOptions().compareTo(IndexOptions.DOCS_AND_FREQS_AND_POSITIONS) >= 0;