import: fix memory leak when importing dives

A long standing issue: the dives_to_add, etc. tables need to be
manually freed. This kind of problem wouldn't arise with proper
C++ data structures.

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

commands/command_divelist.cpp

@@ -521,6 +521,11 @@ ImportDives::ImportDives(struct divelog *log, int flags, const QString &source)
 			continue;
 		filterPresetsToAdd.emplace_back(preset.name, preset.data);
 	}
+
+	free(dives_to_add.dives);
+	free(dives_to_remove.dives);
+	free(trips_to_add.trips);
+	free(sites_to_add.dive_sites);
 }
 
 bool ImportDives::workToBeDone()

core/divelist.c

@@ -1007,6 +1007,10 @@ void add_imported_dives(struct divelog *import_log, int flags)
 	current_dive = divelog.dives->nr > 0 ? divelog.dives->dives[divelog.dives->nr - 1] : NULL;
 
 	free_device_table(devices_to_add);
+	free(dives_to_add.dives);
+	free(dives_to_remove.dives);
+	free(trips_to_add.trips);
+	free(dive_sites_to_add.dive_sites);
 
 	/* Inform frontend of reset data. This should reset all the models. */
 	emit_reset_signal();