fairland: Fix checking of distance arguments

main() rejects the distance between continents when it exceeds WORLD_X
/ 2 and WORLD_Y / 2, and the distance between continents and islands
when it exceeds WORLD_Y and WORLD_Y.  Nuts.  Has always been that way.

Reject either when it exceeds the maximum distance between sectors.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>

diff --git a/src/util/fairland.c b/src/util/fairland.c
index 9dca8aa2ce2ede02cadb002179af19cacc98d785..4cea6e574ec137042f8bd19bd7ee9fedaf3aaa8c 100644 (file)
--- a/src/util/fairland.c
+++ b/src/util/fairland.c
@@ -382,6 +382,8 @@ usage(void)
 static void
 parse_args(int argc, char *argv[])
 {
+    int dist_max = mapdist(0, 0, WORLD_X / 2, WORLD_Y / 2);
+
     if (argc < 2) {
        help("missing arguments");
        exit(1);
@@ -448,7 +450,7 @@ parse_args(int argc, char *argv[])
                program_name);
        exit(1);
     }
-    if (di > WORLD_X / 2 || di > WORLD_Y / 2) {
+    if (di > dist_max) {
        fprintf(stderr, "%s: distance between continents too large\n",
                program_name);
        exit(1);
@@ -462,7 +464,7 @@ parse_args(int argc, char *argv[])
                program_name);
        exit(1);
     }
-    if (id > WORLD_X || id > WORLD_Y) {
+    if (id > dist_max) {
        fprintf(stderr,
                "%s: distance from islands to continents too large\n",
                program_name);