Clean up path finding in unit_sub()

Don't claim the destination sector is unreachable when the best path
is longer than 1023 characters for land units or 99 characters for
ships.  Instead, report that the path is too long.  Up the limit for
ships to 1023 characters.

diff --git a/src/lib/subs/unitsub.c b/src/lib/subs/unitsub.c
index 4d2d3d99bc6230b3b12f33aa01093fec833e2813..ee8376bf40b6e5ccc1f98a76ec75c154402df73f 100644 (file)
--- a/src/lib/subs/unitsub.c
+++ b/src/lib/subs/unitsub.c
@@ -28,7 +28,7 @@
  *
  *  Known contributors to this file:
  *     Ron Koenderink, 2007
- *     Markus Armbruster, 2009
+ *     Markus Armbruster, 2009-2011
  */
 
 #include <config.h>
@@ -138,9 +138,9 @@ unit_path(int together, struct empobj *unit, char *buf)
 {
     coord destx;
     coord desty;
-    struct sctstr d_sect, sect;
+    struct sctstr sect;
     size_t len;
-    char *cp;
+    double c;
     int mtype;
 
     if (CANT_HAPPEN(unit->ef_type != EF_LAND && unit->ef_type != EF_SHIP))
@@ -152,34 +152,17 @@ unit_path(int together, struct empobj *unit, char *buf)
        pr("Cannot go to a destination sector if not all starting in the same sector\n");
        return NULL;
     }
-    if (!getsect(destx, desty, &d_sect)) {
-       pr("%d,%d is not a sector\n", destx, desty);
-       return NULL;
-    }
     if (unit->ef_type == EF_SHIP) {
-       if (path_find(unit->x, unit->y, d_sect.sct_x, d_sect.sct_y,
-                     player->cnum, MOB_SAIL) < 0)
-           cp = NULL;
-       else {
-           len = path_find_route(buf, 100, unit->x, unit->y,
-                                 d_sect.sct_x, d_sect.sct_y);
-           if (len >= 100)
-               cp = NULL;
-           else {
-               if (len == 0)
-                   strcpy(buf, "h");
-               cp = buf;
-           }
-       }
-       if (!cp || unit->mobil <= 0) {
+       c = path_find(unit->x, unit->y, destx, desty,
+                     player->cnum, MOB_SAIL);
+       if (c < 0 || unit->mobil <= 0) {
            pr("Can't get to '%s' right now.\n",
-              xyas(d_sect.sct_x, d_sect.sct_y, player->cnum));
+              xyas(destx, desty, player->cnum));
            return NULL;
        }
     } else {
        getsect(unit->x, unit->y, &sect);
        mtype = lnd_mobtype((struct lndstr *)unit);
-       buf[0] = 0;
        /*
         * Note: passing sect.sct_own for actor is funny, but works:
         * its only effect is to confine the search to that nation's
@@ -187,30 +170,30 @@ unit_path(int together, struct empobj *unit, char *buf)
         * different for marching in allied land, and passing it would
         * break path finding there.
         */
-       if (path_find(sect.sct_x, sect.sct_y, d_sect.sct_x, d_sect.sct_y,
-                     sect.sct_own, mtype) < 0)
-           cp = NULL;
-       else {
-           len = path_find_route(buf, 1024,
-                                 sect.sct_x, sect.sct_y,
-                                 d_sect.sct_x, d_sect.sct_y);
-           if (len + 1 >= 1024)
-               cp = NULL;
-           else {
-               strcpy(buf + len, "h");
-               cp = buf;
-           }
-       }
-       if (!cp) {
+       c = path_find(unit->x, unit->y, destx, desty, sect.sct_own, mtype);
+       if (c < 0) {
+           buf[0] = 0;
            pr("No owned %s from %s to %s!\n",
               mtype == MOB_RAIL ? "railway" : "path",
               xyas(unit->x, unit->y, player->cnum),
-              xyas(d_sect.sct_x, d_sect.sct_y, player->cnum));
+              xyas(destx, desty, player->cnum));
            return NULL;
        }
-       pr("Using path '%s'\n", cp);
     }
-    return cp;
+    len = path_find_route(buf, sizeof(buf), unit->x, unit->y, destx, desty);
+    if (len == 0 || unit->ef_type == EF_LAND) {
+       if (len + 1 < sizeof(buf))
+           strcpy(buf + len, "h");
+       len++;
+    }
+    if (len >= sizeof(buf)) {
+       pr("Can't handle path to %s, it's too long, sorry\n",
+          xyas(destx, desty, player->cnum));
+       return NULL;
+    }
+    if (unit->ef_type == EF_LAND)
+       pr("Using path '%s'\n", buf);
+    return buf;
 }
 
 void