From f58079bc5d29a46fe26c45ff85864e00ccffce23 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beat=20K=C3=BCng?= <beat-kueng@gmx.net>
Date: Fri, 24 May 2019 11:41:43 +0200
Subject: [PATCH] pxh.cpp: fix invalid reference if words is empty

This can happen for example if 'line' is a space.
---
 platforms/posix/src/px4_daemon/pxh.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/platforms/posix/src/px4_daemon/pxh.cpp b/platforms/posix/src/px4_daemon/pxh.cpp
index 4544878a33..8858934fe6 100644
--- a/platforms/posix/src/px4_daemon/pxh.cpp
+++ b/platforms/posix/src/px4_daemon/pxh.cpp
@@ -84,6 +84,10 @@ int Pxh::process_line(const std::string &line, bool silently_fail)
 		words.push_back(word);
 	}
 
+	if (words.empty()) {
+		return 0;
+	}
+
 	const std::string &command(words.front());
 
 	if (_apps.find(command) != _apps.end()) {