From d311045018450d5bbecc846c9dab0b496b51cff0 Mon Sep 17 00:00:00 2001
From: James Turner <jmt@Bishop.local>
Date: Sat, 29 Dec 2012 13:45:27 +0000
Subject: [PATCH] Bug 974, GPS exceptions at end-of-route.

One of the two route termination conditions was improperly handled, leading to bad leg/wpt indices and exceptions from the GPS code. Detect passing the final waypoint in a more robust way now.

Also fix the GPS code to avoid turn computation on the final leg.
---
 src/Autopilot/route_mgr.cxx | 44 ++++++++++++++++++++-----------------
 src/Autopilot/route_mgr.hxx |  5 +++++
 src/Instrumentation/gps.cxx | 12 ++++------
 3 files changed, 33 insertions(+), 28 deletions(-)

diff --git a/src/Autopilot/route_mgr.cxx b/src/Autopilot/route_mgr.cxx
index b084c45ad..5fe1466cb 100644
--- a/src/Autopilot/route_mgr.cxx
+++ b/src/Autopilot/route_mgr.cxx
@@ -453,7 +453,7 @@ void FGRouteMgr::update( double dt )
   }
 
   if (checkFinished()) {
-    // maybe we're done
+    endOfRoute();
   }
   
 // basic course/distance information
@@ -535,14 +535,11 @@ int FGRouteMgr::currentIndex() const
 
 Waypt* FGRouteMgr::wayptAtIndex(int index) const
 {
-  if (_plan) {
-    FlightPlan::Leg* leg = _plan->legAtIndex(index);
-    if (leg) {
-      return leg->waypoint();
-    }
+  if (!_plan) {
+    throw sg_range_exception("wayptAtindex: no flightplan");
   }
   
-  return NULL;
+  return _plan->legAtIndex(index)->waypoint();
 }
 
 int FGRouteMgr::numLegs() const
@@ -590,8 +587,12 @@ void FGRouteMgr::removeLegAtIndex(int aIndex)
 void FGRouteMgr::waypointsChanged()
 {
   update_mirror();
-   _edited->fireValueChanged();
-  checkFinished();
+  _edited->fireValueChanged();
+  
+// removing waypoints, deactivate if we hit the end.
+  if (currentIndex() >= numLegs()) {
+    endOfRoute();
+  }
 }
 
 // mirror internal route to the property system for inspection by other subsystems
@@ -802,11 +803,21 @@ void FGRouteMgr::sequence()
     return;
   }
   
-  if (checkFinished()) {
+  int nextIndex = _plan->currentIndex() + 1;
+  if (nextIndex >= _plan->numLegs()) {
+    SG_LOG(SG_AUTOPILOT, SG_INFO, "sequenced on final leg, deactivating route");
+    endOfRoute();
     return;
   }
-  
-  _plan->setCurrentIndex(_plan->currentIndex() + 1);
+
+  _plan->setCurrentIndex(nextIndex);
+}
+
+void FGRouteMgr::endOfRoute()
+{
+  SG_LOG(SG_AUTOPILOT, SG_INFO, "reached end of active route");
+  _finished->fireValueChanged();
+  active->setBoolValue(false);
 }
 
 bool FGRouteMgr::checkFinished()
@@ -824,15 +835,8 @@ bool FGRouteMgr::checkFinished()
     done = weightOnWheels->getBoolValue() && (gs < 25);
   }
   
-// also done if we hit the final waypoint
-  if (_plan->currentIndex() >= _plan->numLegs()) {
-    done = true;
-  }
-  
   if (done) {
-    SG_LOG(SG_AUTOPILOT, SG_INFO, "reached end of active route");
-    _finished->fireValueChanged();
-    active->setBoolValue(false);
+    SG_LOG(SG_AUTOPILOT, SG_INFO, "checkFinished: on the ground on destination runway, we're done");
   }
   
   return done;
diff --git a/src/Autopilot/route_mgr.hxx b/src/Autopilot/route_mgr.hxx
index baa5e2c50..b66a06b72 100644
--- a/src/Autopilot/route_mgr.hxx
+++ b/src/Autopilot/route_mgr.hxx
@@ -194,6 +194,11 @@ private:
      */
     bool checkFinished();
     
+    /*
+     * update state when we pass the final waypoint
+     */
+    void endOfRoute();
+    
     /**
      * Predicate for helping the UI - test if at least one waypoint was
      * entered by the user (as opposed to being generated by the route-manager)
diff --git a/src/Instrumentation/gps.cxx b/src/Instrumentation/gps.cxx
index 84ef13e35..5f04de2e6 100644
--- a/src/Instrumentation/gps.cxx
+++ b/src/Instrumentation/gps.cxx
@@ -877,18 +877,14 @@ double GPS::computeTurnProgress(double aBearing) const
 void GPS::computeTurnData()
 {
   _computeTurnData = false;
-  if (_mode != "leg") { // and approach modes in the future
+  int nextIndex = _routeMgr->currentIndex() + 1;
+  if ((_mode != "leg") || (nextIndex >= _routeMgr->numWaypts())) {
     _anticipateTurn = false;
     return;
   }
   
-  WayptRef next = _routeMgr->wayptAtIndex(_routeMgr->currentIndex() + 1);
-  if (!next || next->flag(WPT_DYNAMIC)) {
-    _anticipateTurn = false;
-    return;
-  }
-  
-  if (!_config.turnAnticipationEnabled()) {
+  WayptRef next = _routeMgr->wayptAtIndex(nextIndex);
+  if (next->flag(WPT_DYNAMIC) || !_config.turnAnticipationEnabled()) {
     _anticipateTurn = false;
     return;
   }