[Freeciv-Dev] (PR#2722) AI ferries having problems unloading

["Per I. Mathisen via RT" <rt@xxxxxxxxxxxxxx>]

AI ferries seem to have more than the usual amount of trouble unloading
their passengers. I don't know why. Anyway, the attached fix works. It is,
however, a rather ugly fix. But then the ferry code is also very ugly.

  - Per

Index: ai/aiunit.c
===================================================================
RCS file: /home/freeciv/CVS/freeciv/ai/aiunit.c,v
retrieving revision 1.248
diff -u -r1.248 aiunit.c
--- ai/aiunit.c 2003/01/02 11:59:29     1.248
+++ ai/aiunit.c 2003/01/03 21:52:58
@@ -2106,10 +2106,6 @@
     /* Then find enemies the hard way */
     find_something_to_kill(pplayer, punit, &dest_x, &dest_y);
     if (!same_pos(punit->x, punit->y, dest_x, dest_y)) {
-     int repeat;
-
-     for(repeat = 0; repeat < 2; repeat++) {
-
       if (!is_tiles_adjacent(punit->x, punit->y, dest_x, dest_y)
           || !can_unit_attack_tile(punit, dest_x, dest_y)
           || (could_unit_move_to_tile(punit, dest_x, dest_y) == 0)) {
@@ -2117,11 +2113,30 @@
          * on a ferry. This fixes the problem (usually). */
         UNIT_LOG(LOG_DEBUG, punit, "mil att gothere -> %d, %d", 
                  dest_x, dest_y);
+        if (is_ground_unit(punit)
+            && map_get_tile(punit->x, punit->y)->terrain == T_OCEAN
+            && is_normal_map_pos(punit->goto_dest_x,
+                                 punit->goto_dest_y)
+            && map_get_tile(punit->goto_dest_x,
+                            punit->goto_dest_y)->terrain != T_OCEAN) {
+          /* Ensure valid beach head. */
+          int x = punit->goto_dest_x, y = punit->goto_dest_y;
+
+          if (find_beachhead(punit, x, y, &x, &y)) {
+            punit->goto_dest_x = x;
+            punit->goto_dest_y = y;
+            if (is_tiles_adjacent(punit->x, punit->y, x, y)) {
+              if (!ai_unit_move(punit, x, y)) {
+                return; /* died */
+              }
+            }
+          }
+        }
         if (ai_military_gothere(pplayer, punit, dest_x, dest_y) <= 0) {
           /* Died or got stuck */
           return;
         }
-      } else {
+      } else if (can_unit_attack_tile(punit, dest_x, dest_y)) {
         /* Close combat. fstk sometimes want us to attack an adjacent
          * enemy that rampage wouldn't */
         UNIT_LOG(LOG_DEBUG, punit, "mil att bash -> %d, %d", dest_x, dest_y);
@@ -2130,8 +2145,6 @@
           return;
         }
       }
-
-     } /* for-loop */
     } else {
       /* FIXME: This happens a bit too often! */
       UNIT_LOG(LOG_DEBUG, punit, "fstk didn't find us a worthy target!");