Fix UI waypoint numbering.

The flight plan used to not include a waypoint for departure, so a few
places would create one for the sake of the UI, or were built to assume
there was a missing waypoint that was okay to ignore. At some point we
added them to the flight plan, but never updated the UI, so the waypoint
list in the flight dialog started counting from 1 instead of 0, and the
openapi endpoint wrongly reported two departure waypoints to the front-
end.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/3037.

(cherry picked from commit f7b0dfc3a5)

qt_ui/windows/mission/flight/waypoints/QFlightWaypointList.py

@@ -64,7 +64,23 @@ class QFlightWaypointList(QTableView):
             self.model.setHorizontalHeaderLabels(HEADER_LABELS)
 
             waypoints = self.flight.flight_plan.waypoints
-            for row, waypoint in enumerate(waypoints):
+            # Why [1:]? Qt starts indexing at 1 rather than 0, whereas DCS numbers
+            # waypoints starting with 0, and for whatever reason Qt crashes whenever I
+            # set the vertical labels manually.
+            #
+            # Starting with the second waypoint is a bit of a hack, but it's also the
+            # historical behavior anyway. This view used to have waypoints starting at 1
+            # and just didn't show the departure waypoint because the departure waypoint
+            # wasn't actually part of the flight plan tracked by Liberation. That
+            # changed at some point, so now we need to skip it manually to preserve that
+            # behavior.
+            #
+            # It really ought to show the departure waypoint and start indexing at 0,
+            # but since this all pending a move to React anyway, it's not worth fighting
+            # the Qt crashes for now.
+            #
+            # https://github.com/dcs-liberation/dcs_liberation/issues/3037
+            for row, waypoint in enumerate(waypoints[1:]):
                 self._add_waypoint_row(row, self.flight, waypoint)
             self.selectionModel().setCurrentIndex(
                 self.model.index(current_index, 0), QItemSelectionModel.Select