From 193017672a3a283a2e5bb85f1002f656a4e5e156 Mon Sep 17 00:00:00 2001
From: jimczi <jimczi@apache.org>
Date: Tue, 29 Jan 2019 20:31:24 +0100
Subject: [PATCH] Handle completion suggestion without contexts

This change fixes the handling of completion suggestion without contexts.

Relates #36996
---
 .../suggest/completion/TopSuggestGroupDocsCollector.java      | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/server/src/main/java/org/elasticsearch/search/suggest/completion/TopSuggestGroupDocsCollector.java b/server/src/main/java/org/elasticsearch/search/suggest/completion/TopSuggestGroupDocsCollector.java
index 3dfb38bef9dd4..30c642dcdeb3b 100644
--- a/server/src/main/java/org/elasticsearch/search/suggest/completion/TopSuggestGroupDocsCollector.java
+++ b/server/src/main/java/org/elasticsearch/search/suggest/completion/TopSuggestGroupDocsCollector.java
@@ -60,7 +60,9 @@ public void collect(int docID, CharSequence key, CharSequence context, float sco
         int globalDoc = docID + docBase;
         boolean isNewDoc = docContexts.containsKey(globalDoc) == false;
         List<CharSequence> contexts = docContexts.computeIfAbsent(globalDoc, k -> new ArrayList<>());
-        contexts.add(context);
+        if (context != null) {
+            contexts.add(context);
+        }
         if (isNewDoc) {
             super.collect(docID, key, context, score);
         }