From 1c4e3263f8b0b79d1a1a0fcf0c661877e7460207 Mon Sep 17 00:00:00 2001
From: James Turner <zakalawe@mac.com>
Date: Wed, 30 Nov 2016 12:16:23 +0000
Subject: [PATCH] Multiple Flight-Plan clears are a no-op

---
 src/Navaids/FlightPlan.cxx | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/Navaids/FlightPlan.cxx b/src/Navaids/FlightPlan.cxx
index 6e2658da2..4ab75d78f 100644
--- a/src/Navaids/FlightPlan.cxx
+++ b/src/Navaids/FlightPlan.cxx
@@ -225,6 +225,12 @@ void FlightPlan::deleteIndex(int aIndex)
   
 void FlightPlan::clear()
 {
+    // some badly behaved CDU implementations call clear on a Nasal timer
+    // during startup.
+    if (_legs.empty() && (_currentIndex < 0)) {
+        return;
+    }
+
   lockDelegate();
   _waypointsChanged = true;
   _currentWaypointChanged = true;