fiddle with nmea waypoint status tracking. (#325)

Traditionally nmea looks at the Waypoint data member Q
to decide if the Waypoint has been added on to a global list, and
if it has not it deletes the Waypoint so we don't leak memory.

This is problematic when we change the waypoint lists so queues
aren't used.

To overcome this difficulty nmea now uses a derived class of
Waypoint that tracks if the Waypoint has been added or not.

diff --git a/nmea.cc b/nmea.cc
index 5d4e3919b28418253036261ca9a0fa2f7f126257..810d9833c81f7b7922c2d899e8bdb5cc6db2f2ce 100644 (file)
--- a/nmea.cc
+++ b/nmea.cc
@@ -155,6 +155,11 @@ time I have seen this is when the recording stops suddenly, where the last
 sentence is truncated - and missing part of the line, including the checksum.
 */
 
+struct NmeaWaypoint : Waypoint
+{
+  bool added{false};
+};
+
 typedef enum {
   gp_unknown = 0,
   gpgga,
@@ -173,11 +178,11 @@ static route_head* trk_head;
 static short_handle mkshort_handle;
 static preferred_posn_type posn_type;
 static struct tm tm;
-static Waypoint* curr_waypt;
-static Waypoint* last_waypt;
+static NmeaWaypoint* curr_waypt;
+static NmeaWaypoint* last_waypt;
 static void* gbser_handle;
 static QString posn_fname;
-static QList<Waypoint*> pcmpt_head;
+static QList<NmeaWaypoint*> pcmpt_head;
 
 static int without_date;       /* number of created trackpoints without a valid date */
 static struct tm opt_tm;       /* converted "date" parameter */
@@ -246,7 +251,7 @@ nmea_cksum(const char* const buf)
 }
 
 static void
-nmea_add_wpt(Waypoint* wpt, route_head* trk)
+nmea_add_base_wpt(Waypoint* wpt, route_head* trk)
 {
   if (datum != DATUM_WGS84) {
     double lat, lon, alt;
@@ -264,9 +269,16 @@ nmea_add_wpt(Waypoint* wpt, route_head* trk)
 }
 
 static void
-nmea_release_wpt(Waypoint* wpt)
+nmea_add_wpt(NmeaWaypoint* wpt, route_head* trk)
+{
+  wpt->added = true;
+  nmea_add_base_wpt(wpt, trk);
+}
+
+static void
+nmea_release_wpt(NmeaWaypoint* wpt)
 {
-  if (wpt && ((wpt->Q.next == nullptr) || (wpt->Q.next == &wpt->Q))) {
+  if (wpt && !wpt->added) {
     /* This waypoint isn't queued.
        Release it, because we don't have any reference to this
        waypoint (! memory leak !) */
@@ -301,12 +313,12 @@ nmea_rd_init(const QString& fname)
   if (getposn) {
     posn_status st;
     nmea_rd_posn_init(fname);
-    Waypoint* wpt = nmea_rd_posn(&st);
+    auto wpt = nmea_rd_posn(&st);
     if (!wpt) {
       return;
     }
     wpt->shortname = "Position";
-    nmea_add_wpt(wpt, nullptr);
+    nmea_add_base_wpt(wpt, nullptr);
     return;
   }
 
@@ -428,7 +440,7 @@ gpgll_parse(char* ibuf)
   hms = hms / 100;
   tm.tm_hour = hms % 100;
 
-  Waypoint* waypt = new Waypoint;
+  auto waypt = new NmeaWaypoint;
 
   nmea_set_waypoint_time(waypt, &tm, fsec);
 
@@ -499,7 +511,7 @@ gpgga_parse(char* ibuf)
   hms = hms / 100;
   tm.tm_hour = (long) hms % 100;
 
-  Waypoint* waypt = new Waypoint;
+  auto waypt = new NmeaWaypoint;
 
   nmea_set_waypoint_time(waypt, &tm, fsec);
 
@@ -609,7 +621,7 @@ gprmc_parse(char* ibuf)
     return;
   }
 
-  Waypoint* waypt = new Waypoint;
+  auto waypt = new NmeaWaypoint;
 
   WAYPT_SET(waypt, speed, KNOTS_TO_MPS(speed));
   WAYPT_SET(waypt, course, course);
@@ -663,7 +675,7 @@ gpwpl_parse(char* ibuf)
     lngdeg = -lngdeg;
   }
 
-  Waypoint* waypt = new Waypoint;
+  auto waypt = new NmeaWaypoint;
   waypt->latitude = ddmm2degrees(latdeg);
   waypt->longitude = ddmm2degrees(lngdeg);
   waypt->shortname = sname;
@@ -822,7 +834,7 @@ pcmpt_parse(char* ibuf)
   }
 
   if (lat || lon) {
-    curr_waypt = new Waypoint;
+    curr_waypt = new NmeaWaypoint;
     curr_waypt->longitude = pcmpt_deg(lon);
     curr_waypt->latitude = pcmpt_deg(lat);
 
@@ -853,7 +865,7 @@ pcmpt_parse(char* ibuf)
     route_head* trk_head = route_head_alloc();
     track_add_head(trk_head);
     while (!pcmpt_head.isEmpty()) {
-      Waypoint* wpt = pcmpt_head.takeFirst();
+      auto wpt = pcmpt_head.takeFirst();
       nmea_add_wpt(wpt, trk_head);
     }
   }
@@ -1207,7 +1219,7 @@ nmea_rd_posn(posn_status*)
     nmea_parse_one_line(ibuf);
     if (lt != last_read_time) {
       if (last_read_time) {
-        Waypoint* w = curr_waypt;
+        auto w = curr_waypt;
 
         lt = last_read_time;
         curr_waypt = nullptr;