From db247879a92200c2ec34b7229c0281cd593e10b2 Mon Sep 17 00:00:00 2001
From: "Jungtaek Lim (HeartSaVioR)" <kabhwan@gmail.com>
Date: Sat, 14 Sep 2019 22:27:45 +0900
Subject: [PATCH] [SPARK-29046] Fix NPE in SQLConf.get when active SparkContext
 is stopping

---
 .../src/main/scala/org/apache/spark/sql/internal/SQLConf.scala | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
index d9b0a72618c7e..4f3e39ad49afe 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/internal/SQLConf.scala
@@ -139,7 +139,8 @@ object SQLConf {
       }
     } else {
       val isSchedulerEventLoopThread = SparkContext.getActive
-        .map(_.dagScheduler.eventProcessLoop.eventThread)
+        .flatMap { sc => Option(sc.dagScheduler) }
+        .map(_.eventProcessLoop.eventThread)
         .exists(_.getId == Thread.currentThread().getId)
       if (isSchedulerEventLoopThread) {
         // DAGScheduler event loop thread does not have an active SparkSession, the `confGetter`