From e8d0005d002e4b3f5fb00737e8ff17b2f05bac83 Mon Sep 17 00:00:00 2001
From: Yong-Hao Zou <yonghaoz1994@gmail.com>
Date: Fri, 13 Aug 2021 01:27:33 +0800
Subject: [PATCH] Fix null pointer in amcl on_cleanup (#2503)

---
 nav2_amcl/src/amcl_node.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/nav2_amcl/src/amcl_node.cpp b/nav2_amcl/src/amcl_node.cpp
index 0e4fc209119..f1c0a6e5561 100644
--- a/nav2_amcl/src/amcl_node.cpp
+++ b/nav2_amcl/src/amcl_node.cpp
@@ -335,8 +335,10 @@ AmclNode::on_cleanup(const rclcpp_lifecycle::State & /*state*/)
   laser_scan_sub_.reset();
 
   // Map
-  map_free(map_);
-  map_ = nullptr;
+  if (map_ != NULL) {
+    map_free(map_);
+    map_ = nullptr;
+  }
   first_map_received_ = false;
   free_space_indices.resize(0);