From 2239eb26607b338e9df5944bf562d46cd2f87d32 Mon Sep 17 00:00:00 2001
From: jmt <jmt>
Date: Sun, 10 Jan 2010 23:34:58 +0000
Subject: [PATCH] GPS: guard against empty command strings in the
 route-manager.

---
 src/Autopilot/route_mgr.cxx | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Autopilot/route_mgr.cxx b/src/Autopilot/route_mgr.cxx
index bbd2db96b..45e3c922f 100644
--- a/src/Autopilot/route_mgr.cxx
+++ b/src/Autopilot/route_mgr.cxx
@@ -455,6 +455,10 @@ void FGRouteMgr::update_mirror() {
 void FGRouteMgr::InputListener::valueChanged(SGPropertyNode *prop)
 {
     const char *s = prop->getStringValue();
+    if (strlen(s) == 0) {
+      return;
+    }
+    
     if (!strcmp(s, "@CLEAR"))
         mgr->init();
     else if (!strcmp(s, "@ACTIVATE"))