From 15a218d02e2ffd17b8c48bbf67369208b1b537c9 Mon Sep 17 00:00:00 2001
From: Yannick Welsch <yannick@welsch.lu>
Date: Wed, 16 Jan 2019 19:47:24 +0100
Subject: [PATCH 1/2] Fix assertion at end of forceRefreshes

---
 .../elasticsearch/index/shard/RefreshListeners.java    | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/server/src/main/java/org/elasticsearch/index/shard/RefreshListeners.java b/server/src/main/java/org/elasticsearch/index/shard/RefreshListeners.java
index b4b9e13f7e063..2edeed56015e3 100644
--- a/server/src/main/java/org/elasticsearch/index/shard/RefreshListeners.java
+++ b/server/src/main/java/org/elasticsearch/index/shard/RefreshListeners.java
@@ -129,13 +129,12 @@ public boolean addOrNotify(Translog.Location location, Consumer<Boolean> listene
             return true;
         }
         synchronized (this) {
+            if (closed) {
+                throw new IllegalStateException("can't wait for refresh on a closed index");
+            }
             List<Tuple<Translog.Location, Consumer<Boolean>>> listeners = refreshListeners;
             if (listeners == null) {
-                if (closed) {
-                    throw new IllegalStateException("can't wait for refresh on a closed index");
-                }
                 listeners = new ArrayList<>();
-                refreshListeners = listeners;
             }
             if (refreshForcers == 0 && listeners.size() < getMaxRefreshListeners.getAsInt()) {
                 ThreadContext.StoredContext storedContext = threadContext.newStoredContext(true);
@@ -145,6 +144,9 @@ public boolean addOrNotify(Translog.Location location, Consumer<Boolean> listene
                         listener.accept(forced);
                     }
                 };
+                if (refreshListeners == null) {
+                    refreshListeners = listeners;
+                }
                 // We have a free slot so register the listener
                 listeners.add(new Tuple<>(location, contextPreservingListener));
                 return false;

From ee153065dab0dca553c4dbd576a2511250643c9f Mon Sep 17 00:00:00 2001
From: Armin Braun <me@obrown.io>
Date: Thu, 17 Jan 2019 14:45:13 +0100
Subject: [PATCH 2/2] CR: Avoid needlessly instantiating ArrayList

---
 .../elasticsearch/index/shard/RefreshListeners.java   | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/server/src/main/java/org/elasticsearch/index/shard/RefreshListeners.java b/server/src/main/java/org/elasticsearch/index/shard/RefreshListeners.java
index 2edeed56015e3..713563eb111ba 100644
--- a/server/src/main/java/org/elasticsearch/index/shard/RefreshListeners.java
+++ b/server/src/main/java/org/elasticsearch/index/shard/RefreshListeners.java
@@ -133,10 +133,8 @@ public boolean addOrNotify(Translog.Location location, Consumer<Boolean> listene
                 throw new IllegalStateException("can't wait for refresh on a closed index");
             }
             List<Tuple<Translog.Location, Consumer<Boolean>>> listeners = refreshListeners;
-            if (listeners == null) {
-                listeners = new ArrayList<>();
-            }
-            if (refreshForcers == 0 && listeners.size() < getMaxRefreshListeners.getAsInt()) {
+            final int maxRefreshes = getMaxRefreshListeners.getAsInt();
+            if (refreshForcers == 0 && maxRefreshes > 0 && (listeners == null || listeners.size() < maxRefreshes)) {
                 ThreadContext.StoredContext storedContext = threadContext.newStoredContext(true);
                 Consumer<Boolean> contextPreservingListener = forced -> {
                     try (ThreadContext.StoredContext ignore = threadContext.stashContext()) {
@@ -144,11 +142,12 @@ public boolean addOrNotify(Translog.Location location, Consumer<Boolean> listene
                         listener.accept(forced);
                     }
                 };
-                if (refreshListeners == null) {
-                    refreshListeners = listeners;
+                if (listeners == null) {
+                    listeners = new ArrayList<>();
                 }
                 // We have a free slot so register the listener
                 listeners.add(new Tuple<>(location, contextPreservingListener));
+                refreshListeners = listeners;
                 return false;
             }
         }