Cleanup: provide printGPSCoords in C and C++ versions

printGPSCoords() returned a newly allocated C-style string. Most
callers simply made a QString out of it and freed the C-style string.
This is paradoxical, as printGPSCoords internally works with QStrings
and converts them to C-style on return.

Therefore, let printGPSCoords() return a QString and create a
printGPSCoordsC() wrapper for the two C-callers.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/gpslocation.cpp

@@ -137,9 +137,7 @@ QString GpsLocation::currentPosition()
 		if (delta < 300) {
 			// we can simply use the last position that we tracked
 			gpsTracker gt = m_trackers.last();
-			char *gps = printGPSCoords(&gt.location);
-			QString gpsString = gps;
-			free(gps);
+			QString gpsString = printGPSCoords(&gt.location);
 			qDebug() << "returning last position" << gpsString;
 			return gpsString;
 		} else {

core/load-git.c

@@ -164,7 +164,7 @@ static void parse_dive_gps(char *line, struct membuffer *str, void *_dive)
 			dive->dive_site = ds;
 	} else {
 		if (dive_site_has_gps_location(ds) && !same_location(&ds->location, &location)) {
-			char *coords = printGPSCoords(&location);
+			char *coords = printGPSCoordsC(&location);
 			// we have a dive site that already has GPS coordinates
 			ds->notes = add_to_string(ds->notes, translate("gettextFromC", "multiple GPS locations for this dive site; also %s\n"), coords);
 			free(coords);

core/parse-xml.c

@@ -1201,7 +1201,7 @@ static void gps_in_dive(char *buffer, struct dive *dive, struct parser_state *st
 			fprintf(stderr, "dive site uuid in dive, but gps location (%10.6f/%10.6f) different from dive location (%10.6f/%10.6f)\n",
 				ds->location.lat.udeg / 1000000.0, ds->location.lon.udeg / 1000000.0,
 				location.lat.udeg / 1000000.0, location.lon.udeg / 1000000.0);
-			char *coords = printGPSCoords(&location);
+			char *coords = printGPSCoordsC(&location);
 			ds->notes = add_to_string(ds->notes, translate("gettextFromC", "multiple GPS locations for this dive site; also %s\n"), coords);
 			free(coords);
 		} else {

core/qthelper.cpp

@@ -72,7 +72,7 @@ QString distance_string(int distanceInMeters)
 	return str;
 }
 
-extern "C" char *printGPSCoords(const location_t *location)
+QString printGPSCoords(const location_t *location)
 {
 	int lat = location->lat.udeg;
 	int lon = location->lon.udeg;
@@ -82,7 +82,7 @@ extern "C" char *printGPSCoords(const location_t *location)
 	QString lath, lonh, result;
 
 	if (!has_location(location))
-		return strdup("");
+		return QString();
 
 	if (prefs.coordinates_traditional) {
 		lath = lat >= 0 ? gettextFromC::tr("N") : gettextFromC::tr("S");
@@ -101,7 +101,12 @@ extern "C" char *printGPSCoords(const location_t *location)
 	} else {
 		result.sprintf("%f %f", (double) lat / 1000000.0, (double) lon / 1000000.0);
 	}
-	return copy_qstring(result);
+	return result;
+}
+
+extern "C" char *printGPSCoordsC(const location_t *location)
+{
+	return copy_qstring(printGPSCoords(location));
 }
 
 /**

core/qthelper.h

@@ -82,6 +82,7 @@ QString uiLanguage(QLocale *callerLoc);
 QLocale getLocale();
 void selectedDivesGasUsed(QVector<QPair<QString, int> > &gasUsed);
 QString getUserAgent();
+QString printGPSCoords(const location_t *loc);
 
 #if defined __APPLE__
 #define TITLE_OR_TEXT(_t, _m) "", _t + "\n" + _m
@@ -123,7 +124,7 @@ void moveInVector(Vector &v, int rangeBegin, int rangeEnd, int destination)
 extern "C" {
 #endif
 
-char *printGPSCoords(const location_t *loc);
+char *printGPSCoordsC(const location_t *loc);
 bool in_planner();
 bool getProxyString(char **buffer);
 bool canReachCloudServer();

core/subsurface-qt/DiveObjectHelper.cpp

@@ -114,10 +114,7 @@ QString DiveObjectHelper::gps() const
 	struct dive_site *ds = m_dive->dive_site;
 	if (!ds)
 		return QString();
-	char *gps = printGPSCoords(&ds->location);
-	QString res = gps;
-	free(gps);
-	return res;
+	return printGPSCoords(&ds->location);
 }
 
 QString DiveObjectHelper::gps_decimal() const