[gpsd-dev] [PATCH] Fix on NMEA driver 2D mode

[José Miguel Gonçalves]

Hi,

While working with a Septentrio PolarRx2 receiver, I've noticed that I never got 
2D fixes with xgps, while the Septentrio proprietary software told me that it had 
a fix. I've tracked down the bug to the GGA processing in the NMEA driver.

Best regards,
José Gonçalves

diff --git a/driver_nmea.c b/driver_nmea.c
index 8eb5c1f..e1626f3 100644
--- a/driver_nmea.c
+++ b/driver_nmea.c
@@ -364,12 +364,11 @@ static gps_mask_t processGPGGA(int c UNUSED, char 
*field[],
        /*
         * SiRF chipsets up to version 2.2 report a null altitude field.
         * See <http://www.sirf.com/Downloads/Technical/apnt0033.pdf>.
-        * If we see this, force mode to 2D at most.
+        * If we see this, force mode to 2D.
         */
        if (altitude[0] == '\0') {
-           if (session->newdata.mode == MODE_3D) {
-               session->newdata.mode =
-                   session->gpsdata.status ? MODE_2D : MODE_NO_FIX;
+           if (session->newdata.mode != MODE_2D) {
+               session->newdata.mode = MODE_2D;
                mask |= MODE_SET;
            }
        } else {