--- a/ship_cmd.c	Sat May 14 06:48:14 2005 +0000
+++ b/ship_cmd.c	Sat May 14 12:36:16 2005 +0000
@@ -1067,36 +1067,39 @@
 	return 0;
 }
 
-
-// p1 = vehicle
-// p2 = new cargo (0xFF)
-// p2 = skip check for stopped in hanger (0x0100)
+/** Refits a ship to the specified cargo type.
+ * @param x,y unused
+ * @param p1 vehicle ID of the ship to refit
+ * @param p2 various bitstuffed elements
+ * - p2 = (bit 0-7) - the new cargo type to refit to (p2 & 0xFF)
+ * - p2 = (bit 8)   - skip check for stopped in depot, used by autoreplace (p2 & 0x100)
+ * @todo p2 bit8 check <b>NEEDS TO GO</b>
+ */
 int32 CmdRefitShip(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 {
 	Vehicle *v;
 	int32 cost;
-	byte SkipStoppedInDepotCheck = (p2 & 0x100) >> 8; //excludes the cargo value
-
-	p2 = p2 & 0xFF;
+	CargoID new_cid = p2 & 0xFF; //gets the cargo number
+	bool SkipStoppedInDepotCheck = !!HASBIT(p2, 8); // XXX - needs to go, yes?
 
 	if (!IsVehicleIndex(p1)) return CMD_ERROR;
 
 	v = GetVehicle(p1);
 
-	if (v->type != VEH_Ship || !CheckOwnership(v->owner))
-		return CMD_ERROR;
+	if (v->type != VEH_Ship || !CheckOwnership(v->owner)) return CMD_ERROR;
+	if (!SkipStoppedInDepotCheck) {
+		if (!IsTileDepotType(v->tile, TRANSPORT_WATER) || !(v->vehstatus&VS_STOPPED) || v->u.ship.state != 0x80)
+			return_cmd_error(STR_980B_SHIP_MUST_BE_STOPPED_IN);
+	}
 
-	if (!( SkipStoppedInDepotCheck )) {
-		if (!IsTileDepotType(v->tile, TRANSPORT_WATER) ||
-				!(v->vehstatus&VS_STOPPED) ||
-				v->u.ship.state != 0x80)
-			return_cmd_error(STR_980B_SHIP_MUST_BE_STOPPED_IN);
-		}
+	/* Check cargo */
+	if (!ShipVehInfo(v->engine_type)->refittable) return CMD_ERROR;
+	if (new_cid > NUM_CARGO || !CanRefitTo(v, new_cid)) return CMD_ERROR;
 
 	SET_EXPENSES_TYPE(EXPENSES_SHIP_RUN);
 
 	cost = 0;
-	if (IS_HUMAN_PLAYER(v->owner) && (byte)p2 != v->cargo_type) {
+	if (IS_HUMAN_PLAYER(v->owner) && new_cid != v->cargo_type) {
 		cost = _price.ship_base >> 7;
 	}
 
@@ -1105,12 +1108,10 @@
 		//it will be checked if the cargo is valid in CmdRenewVehicle
 		if (!(SkipStoppedInDepotCheck))
 			v->cargo_count = 0;
-		v->cargo_type = (byte)p2;
+		v->cargo_type = new_cid;
 		InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
 	}
 
 	return cost;
 
 }
-
-