Do not write "unknown_alt".

diff --git a/dmtlog.c b/dmtlog.c
index 05d70b055f0b61009d126394bae0bcf22e268389..22f2a56e64e43cdd318cd732b2a5ff027b00ba19 100644 (file)
--- a/dmtlog.c
+++ b/dmtlog.c
@@ -649,7 +649,7 @@ track_wpt_cb(const waypoint *wpt)
        
        gbfputdbl(wpt->latitude, fout);
        gbfputdbl(wpt->longitude, fout);
-       gbfputdbl(wpt->altitude, fout);
+       gbfputdbl(wpt->altitude != unknown_alt ? wpt->altitude : 0, fout);
 }
 
 static void
@@ -659,7 +659,7 @@ wpt_cb(const waypoint *wpt)
        
        gbfputdbl(wpt->latitude, fout);
        gbfputdbl(wpt->longitude, fout);
-       gbfputdbl(wpt->altitude, fout);
+       gbfputdbl(wpt->altitude != unknown_alt ? wpt->altitude : 0, fout);
        
        names = 1;
        if (wpt->description && *wpt->description) names = 2;