Bugfix: fix range/ident priority of loaded wpts

When the lat-lon of a waypoint disagrees with the discovered ident by
more than a threshold, assume we have a DB mismatch, and just revert
to a basic wpt specified by lat-lon. This avoids inserting huge
legs by selecting a very distant navaid with matching ident

https://sourceforge.net/p/flightgear/codetickets/1814/

src/Navaids/FlightPlan.cxx

@@ -1111,9 +1111,8 @@ void FlightPlan::loadVersion2XMLRoute(SGPropertyNode_ptr routeData)
   _legs.clear();
   SGPropertyNode_ptr routeNode = routeData->getChild("route", 0);
   if (routeNode.valid()) {
-    for (int i=0; i<routeNode->nChildren(); ++i) {
+    for (auto wpNode : routeNode->getChildren("wp")) {
-      SGPropertyNode_ptr wpNode = routeNode->getChild("wp", i);
+      Leg* l = new Leg{this, Waypt::createFromProperties(this, wpNode)};
-      Leg* l = new Leg(this, Waypt::createFromProperties(this, wpNode));
       _legs.push_back(l);
     } // of route iteration
   }

src/Navaids/airways.cxx

@@ -369,6 +369,7 @@ AirwayRef Airway::findByIdentAndNavaid(const std::string& aIdent, const FGPositi
 
 WayptRef Airway::findEnroute(const std::string &aIdent) const
 {
+    loadWaypoints();
     auto it = std::find_if(_elements.begin(), _elements.end(),
                            [&aIdent](WayptRef w)
     {

src/Navaids/route.cxx

@@ -256,6 +256,9 @@ WayptRef Waypt::createFromProperties(RouteBase* aOwner, SGPropertyNode_ptr aProp
 
 // if we failed to make the waypoint, try again making a basic waypoint.
 // this handles the case where a navaid waypoint is missing, for example
+// we also reject navaids that don't look correct (too far form the specified
+// lat-lon, eg see https://sourceforge.net/p/flightgear/codetickets/1814/ )
+// and again fallback to here.
   WayptRef nd(new BasicWaypt(aOwner));
   nd->initFromProperties(aProp);
   return nd;

src/Navaids/waypoint.cxx

@@ -119,11 +119,21 @@ void NavaidWaypoint::initFromProperties(SGPropertyNode_ptr aProp)
   
   // FIXME - resolve co-located DME, etc
   // is it sufficent just to ignore DMEs, actually?
-  FGPositionedRef nav = FGPositioned::findClosestWithIdent(idn, p, NULL);
+  FGPositionedRef nav = FGPositioned::findClosestWithIdent(idn, p, nullptr);
   if (!nav) {
     throw sg_io_exception("unknown navaid ident:" + idn, 
       "NavaidWaypoint::initFromProperties");
   }
+
+  if (p.isValid() && (SGGeodesy::distanceM(nav->geod(), p) > 4000)) {
+      // the looked up navaid was more than 4000 metres from the lat/lon.
+      // in this case, throw an exception here so we fall back to using
+      // a basic waypoint
+      // see https://sourceforge.net/p/flightgear/codetickets/1814/
+      throw sg_io_exception("Waypoint navaid for ident:" + idn +
+                            " is too far from specified lat/lon in flight-plan",
+                            "NavaidWaypoint::initFromProperties");
+  }
   
   _navaid = nav;
 }

test_suite/unit_tests/Navaids/test_flightplan.cxx

@@ -226,3 +226,51 @@ void FlightplanTests::testParseICANLowLevelRoute()
     bool ok = f->parseICAORouteString(route);
     CPPUNIT_ASSERT(ok);
 }
+
+// https://sourceforge.net/p/flightgear/codetickets/1814/
+void FlightplanTests::testBug1814()
+{
+    const std::string fpXML = R"(<?xml version="1.0" encoding="UTF-8"?>
+                    <PropertyList>
+                        <version type="int">2</version>
+                        <departure>
+                            <airport type="string">SAWG</airport>
+                            <runway type="string">25</runway>
+                        </departure>
+                        <destination>
+                            <airport type="string">SUMU</airport>
+                        </destination>
+                        <route>
+                              <wp n="6">
+                                    <type type="string">navaid</type>
+                                    <ident type="string">PUGLI</ident>
+                                    <lon type="double">-60.552200</lon>
+                                    <lat type="double">-40.490000</lat>
+                                  </wp>
+                            <wp n="7">
+                                <type type="string">navaid</type>
+                                <ident type="string">SIGUL</ident>
+                                <lon type="double">-59.655800</lon>
+                                <lat type="double">-38.312800</lat>
+                            </wp>
+                            <wp n="8">
+                                <type type="string">navaid</type>
+                                <ident type="string">MDP</ident>
+                                <lon type="double">-57.576400</lon>
+                                <lat type="double">-37.929800</lat>
+                            </wp>
+                        </route>
+                    </PropertyList>
+  )";
+
+    std::istringstream stream(fpXML);
+    FlightPlanRef f = new FlightPlan;
+    bool ok = f->load(stream);
+    CPPUNIT_ASSERT(ok);
+
+    auto leg = f->legAtIndex(1);
+    CPPUNIT_ASSERT_EQUAL(std::string("SIGUL"), leg->waypoint()->ident());
+
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(137, leg->distanceNm(), 0.5);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(101, f->legAtIndex(2)->distanceNm(), 0.5);
+}

test_suite/unit_tests/Navaids/test_flightplan.hxx

@@ -18,8 +18,8 @@
  */
 
 
-#ifndef _FG_FLIGHTPLAN_UNIT_TESTS_HXX
+#ifndef FG_FLIGHTPLAN_UNIT_TESTS_HXX
-#define _FG_FLIGHTPLAN_UNIT_TESTS_HXX
+#define FG_FLIGHTPLAN_UNIT_TESTS_HXX
 
 
 #include <cppunit/extensions/HelperMacros.h>
@@ -37,6 +37,8 @@ class FlightplanTests : public CppUnit::TestFixture
     CPPUNIT_TEST(testRoutePathTrivialFlightPlan);
     CPPUNIT_TEST(testBasicAirways);
     CPPUNIT_TEST(testAirwayNetworkRoute);
+    CPPUNIT_TEST(testBug1814);
+
   //  CPPUNIT_TEST(testParseICAORoute);
    // CPPUNIT_TEST(testParseICANLowLevelRoute);
     CPPUNIT_TEST_SUITE_END();
@@ -57,6 +59,7 @@ public:
     void testAirwayNetworkRoute();
     void testParseICAORoute();
     void testParseICANLowLevelRoute();
+    void testBug1814();
 };
 
-#endif  // _FG_FLIGHTPLAN_UNIT_TESTS_HXX
+#endif  // FG_FLIGHTPLAN_UNIT_TESTS_HXX