diff -Nur -X/home/thue/freeciv-dev/no.freeciv freeciv/client/control.c diplbug/client/control.c
--- freeciv/client/control.c	Thu May  4 21:04:27 2000
+++ diplbug/client/control.c	Thu May  4 22:00:02 2000
@@ -501,27 +501,41 @@
 }
 
 /**************************************************************************
-...
-
-  No need to do caravan-specific stuff here any more: server does trade
-  routes to enemy cities automatically, and for friendly cities we wait
-  for the unit to enter the city.  --dwp
-
-  No need to do diplomat-specific stuff here any more: server notifies
-  client whenever diplomat attempts to enter enemy city.  --jjm
+  This function is called whenever the player pressed an arrow key.
 
+  If punit is a diplomat trying to move to a tile with a unit we forward
+  it to popup_diplomat_dialog.
+  We do NOT take into account that punit might be a caravan or a diplomat
+  trying to move into a city; the server will handle those cases.
 **************************************************************************/
 void request_move_unit_direction(struct unit *punit, int dx, int dy)
 {
   int dest_x, dest_y;
   struct unit req_unit;
 
-  dest_x=map_adjust_x(punit->x+dx);
-  dest_y=punit->y+dy;   /* not adjusting on purpose*/   /* why? --dwp */
+  dest_x = map_adjust_x(punit->x+dx);
+  dest_y = punit->y+dy; /* Not adjusted since if it needed to be adjusted it
+			   would mean that we tried to move of the map... */
+
+  /* Catches attempts to move off map */
+  if (!is_real_tile(dest_x, dest_y))
+    return;
+
+  if (unit_flag(punit->type, F_DIPLOMAT)
+      && !map_get_city(dest_x, dest_y) /* handled in the server */
+      && is_diplomat_action_available(punit, DIPLOMAT_ANY_ACTION,
+				      dest_x, dest_y)) {
+    if (diplomat_can_do_action(punit, DIPLOMAT_ANY_ACTION, dest_x, dest_y)) {
+      popup_diplomat_dialog(punit, dest_x, dest_y);
+    } else {
+      append_output_window(_("Game: You don't have enough movement left."));
+    }
+    return;
+  }
 
-  req_unit=*punit;
-  req_unit.x=dest_x;
-  req_unit.y=dest_y;
+  req_unit = *punit;
+  req_unit.x = dest_x;
+  req_unit.y = dest_y;
   send_move_unit(&req_unit);
 }