Ensure that turnout tracks have a turnout id

diff --git a/source/libr2c2/track.cpp b/source/libr2c2/track.cpp
index 51c73c237ccd27a8873ae26effc0a632434dc2c5..ecb86bbad33ad02e20699a05ef7655eb3d2d30a0 100644 (file)
--- a/source/libr2c2/track.cpp
+++ b/source/libr2c2/track.cpp
@@ -123,6 +123,8 @@ void Track::set_turnout_id(unsigned i)
 {
        if(!type.is_turnout())
                throw logic_error("not a turnout");
+       if(!i)
+               throw invalid_argument("Track::set_turnout_id");
 
        turnout_id = i;
        layout.create_blocks(*this);