From 02cb2ca3845bd9e894977051b994057dcc931c32 Mon Sep 17 00:00:00 2001
From: robertl <robertl>
Date: Sat, 24 Apr 2010 06:03:17 +0000
Subject: [PATCH] From Warren Toomey: make more fields in NMEA optional on
 read.

---
 nmea.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/nmea.c b/nmea.c
index 86f11e20a..2f0276f74 100644
--- a/nmea.c
+++ b/nmea.c
@@ -509,22 +509,37 @@ gprmc_parse(char *ibuf)
 	double speed,course;
 	waypoint *waypt;
 	double microseconds;
+	char *dmybuf;
+	int i;
 
 	if (trk_head == NULL) {
 		trk_head = route_head_alloc();
 		track_add_head(trk_head);
 	}
 
-	sscanf(ibuf,"$GPRMC,%lf,%c,%lf,%c,%lf,%c,%lf,%lf,%u",
+	/*
+	 * Read everything except the dmy, in case lngdeg
+	 * and lngdir are missing.
+	 */
+	sscanf(ibuf,"$GPRMC,%lf,%c,%lf,%c,%lf,%c,%lf,%lf",
 		&hms, &fix, &latdeg, &latdir,
 		&lngdeg, &lngdir,
-		&speed, &course, &dmy);
+		&speed, &course);
 
 	if (fix != 'A') {
 		/* ignore this fix - it is invalid */
 		return;
 	}
 
+	/* Skip past nine commas in ibuf to reach the dmy value */
+	for (dmybuf=ibuf,i=0; i<9 && dmybuf != NULL; i++) {
+		dmybuf= strchr(dmybuf, ',');
+		dmybuf++;
+	}
+
+	/* Now read dmy from the correct position */
+	sscanf(dmybuf,"%u", &dmy);
+
 	last_read_time = hms;
 	microseconds = MILLI_TO_MICRO(1000 * (hms - (int)hms));
 	
-- 
2.30.2