From b965171b41e0abdb07ca562eb383a533f25fceb4 Mon Sep 17 00:00:00 2001
From: Johnny Lim <izeye@naver.com>
Date: Tue, 7 Nov 2017 02:22:50 +0900
Subject: [PATCH] Add missing null check in FileSystemWatcher.stopAfter()

Closes gh-10941
---
 .../boot/devtools/filewatch/FileSystemWatcher.java              | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/filewatch/FileSystemWatcher.java b/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/filewatch/FileSystemWatcher.java
index c3530b3b7f..9c44a4e0d3 100644
--- a/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/filewatch/FileSystemWatcher.java
+++ b/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/filewatch/FileSystemWatcher.java
@@ -194,7 +194,7 @@ public class FileSystemWatcher {
 			}
 			this.watchThread = null;
 		}
-		if (Thread.currentThread() != thread) {
+		if (thread != null && Thread.currentThread() != thread) {
 			try {
 				thread.join();
 			}