(svn r10139) -Fix: all inner parts of OpenTTD assume that the resolution is at least 1 by 1, so force the resolution to be always at least 1 by 1.

src/openttd.cpp

@@ -475,6 +475,11 @@ int ttd_main(int argc, char *argv[])
 	if (startyear != INVALID_YEAR) _patches_newgame.starting_year = startyear;
 	if (generation_seed != GENERATE_NEW_SEED) _patches_newgame.generation_seed = generation_seed;
 
+	/* The width and height must be at least 1 pixel, this
+	 * way all internal drawing routines work correctly. */
+	if (_cur_resolution[0] == 0) _cur_resolution[0] = 1;
+	if (_cur_resolution[1] == 0) _cur_resolution[1] = 1;
+
 #if defined(ENABLE_NETWORK)
 	if (dedicated_host) snprintf(_network_server_bind_ip_host, NETWORK_HOSTNAME_LENGTH, "%s", dedicated_host);
 	if (dedicated_port) _network_server_port = dedicated_port;