Honor unknown alt (make zero) on upload.

diff --git a/gpsbabel/magproto.c b/gpsbabel/magproto.c
index c8fb6f9647ce8c8aed989212ba3a1f234802058e..9011e017d1cf3c3c1fd2aef48922c20347fa62f7 100644 (file)
--- a/gpsbabel/magproto.c
+++ b/gpsbabel/magproto.c
@@ -981,7 +981,8 @@ mag_waypt_pr(const waypoint *waypointp)
        sprintf(obuf, "PMGNWPL,%4.3f,%c,%09.3f,%c,%07.lf,M,%-.8s,%-.30s,%s",
                lat, ilon < 0 ? 'N' : 'S',
                lon, ilat < 0 ? 'E' : 'W',
-               waypointp->position.altitude.altitude_meters,
+               waypointp->position.altitude.altitude_meters == unknown_alt ?
+                       0 : waypointp->position.altitude.altitude_meters,
                owpt,
                odesc,
                icon_token);