Fix for route-path when leg 0 is not a runway

Avoid doing turn-computation for the first waypoint, even if it’s not
a runway. Add a unit-test to cover this case.

Reported by Josh Davidson

src/Main/fg_io.cxx

@@ -442,6 +442,9 @@ bool FGIO::isMultiplayerRequested()
     // is easier than checking the raw Options arguments, but works before
     // this subsytem is actuallyt created.
     auto channels = globals->get_channel_options_list();
+    if (!channels)
+        return false; // happens running tests
+    
     auto it = std::find_if(channels->begin(), channels->end(),
                            [](const std::string& channelOption)
                            { return (channelOption.find("multiplay") == 0); });

src/Navaids/routePath.cxx

@@ -405,8 +405,12 @@ public:
               legCourseTrue = rwy->headingDeg();
               flyOver = true;
           } else {
-              // don't set legCourseValid
+              legCourseValid = true;
+              legCourseTrue = next.legCourseTrue;
               turnExitAngle = 0.0;
+              turnExitPos = pos;
+              flyOver = true;
+              return;
           }
       }
 

test_suite/unit_tests/Navaids/test_flightplan.cxx

@@ -12,6 +12,7 @@
 #include <Navaids/navlist.hxx>
 #include <Navaids/navrecord.hxx>
 #include <Navaids/airways.hxx>
+#include <Navaids/fix.hxx>
 
 #include <Airports/airport.hxx>
 
@@ -149,6 +150,30 @@ void FlightplanTests::testRoutePathTrivialFlightPlan()
     CPPUNIT_ASSERT_DOUBLES_EQUAL(0.0, fp1->totalDistanceNm(), 1e-9);
 }
 
+void FlightplanTests::testRoutPathWpt0Midflight()
+{
+    // test behaviour of RoutePath when WP0 is not a runway
+    // happens for the Airbus ND which removes past wpts when sequencing
+    
+    FlightPlanRef fp1 = makeTestFP("KNUQ", "14L", "PHNL", "22R",
+                                   "ROKME WOVAB");
+    RoutePath rtepath(fp1);
+    
+    SGGeodVec vec = rtepath.pathForIndex(0);
+    
+    FGAirportRef ksfo = FGAirport::findByIdent("KSFO");
+    FGFixRef rokme = fgpositioned_cast<FGFix>(FGPositioned::findClosestWithIdent("ROKME", ksfo->geod()));
+    
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(rokme->geod().getLongitudeDeg(), vec.front().getLongitudeDeg(), 0.01);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(rokme->geod().getLatitudeDeg(), vec.front().getLatitudeDeg(), 0.01);
+    
+    SGGeodVec vec2 = rtepath.pathForIndex(1);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(rokme->geod().getLongitudeDeg(), vec2.front().getLongitudeDeg(), 0.01);
+    CPPUNIT_ASSERT_DOUBLES_EQUAL(rokme->geod().getLatitudeDeg(), vec2.front().getLatitudeDeg(), 0.01);
+
+    //CPPUNIT_ASSERT(vec.front()
+}
+
 void FlightplanTests::testBasicAirways()
 {
     Airway* awy = Airway::findByIdent("J547", Airway::HighLevel);

test_suite/unit_tests/Navaids/test_flightplan.hxx

@@ -38,7 +38,8 @@ class FlightplanTests : public CppUnit::TestFixture
     CPPUNIT_TEST(testBasicAirways);
     CPPUNIT_TEST(testAirwayNetworkRoute);
     CPPUNIT_TEST(testBug1814);
-
+    CPPUNIT_TEST(testRoutPathWpt0Midflight);
+    
   //  CPPUNIT_TEST(testParseICAORoute);
    // CPPUNIT_TEST(testParseICANLowLevelRoute);
     CPPUNIT_TEST_SUITE_END();
@@ -60,6 +61,7 @@ public:
     void testParseICAORoute();
     void testParseICANLowLevelRoute();
     void testBug1814();
+    void testRoutPathWpt0Midflight();
 };
 
 #endif  // FG_FLIGHTPLAN_UNIT_TESTS_HXX