From e6224304606e20bbf79280978ba70326eabea575 Mon Sep 17 00:00:00 2001
From: Thomas Gubler <thomasgubler@gmail.com>
Date: Wed, 10 Dec 2014 12:41:54 +0100
Subject: [PATCH] px4 subscriber/nuttx: don't call null callback

---
 src/platforms/px4_subscriber.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/platforms/px4_subscriber.h b/src/platforms/px4_subscriber.h
index e995c6e49d..5d0120f90e 100644
--- a/src/platforms/px4_subscriber.h
+++ b/src/platforms/px4_subscriber.h
@@ -115,6 +115,10 @@ public:
 	 */
 	void update()
 	{
+		if (_callback == nullptr) {
+			return;
+		}
+
 		if (!uORB::Subscription<M>::updated()) {
 			/* Topic not updated, do not call callback */
 			return;