(svn r6001) -Feature: when removing a farm, his farmland is removed too (over time) (based on peter1138's patch, FS#82)

To make this to work, in older games farmland is removed on load, and replanted

openttd.c

@@ -50,6 +50,7 @@
 #include "settings.h"
 #include "genworld.h"
 #include "date.h"
+#include "clear_map.h"
 
 #include <stdarg.h>
 
@@ -1463,5 +1464,27 @@ bool AfterLoadGame(void)
 		}
 	}
 
+	/* From 32 on we save the industry who made the farmland.
+	 *  To give this prettyness to old savegames, we remove all farmfields and
+	 *  plant new ones. */
+	if (CheckSavegameVersion(32)) {
+		Industry *i;
+
+		BEGIN_TILE_LOOP(tile_cur, MapSizeX(), MapSizeY(), 0) {
+			if (IsTileType(tile_cur, MP_CLEAR) && IsClearGround(tile_cur, CLEAR_FIELDS)) {
+				MakeClear(tile_cur, CLEAR_GRASS, 3);
+			}
+		} END_TILE_LOOP(tile_cur, MapSizeX(), MapSizeY(), 0)
+
+		FOR_ALL_INDUSTRIES(i) {
+			uint j;
+
+			if (i->xy == 0) continue;
+			if (i->type == IT_FARM || i->type == IT_FARM_2) {
+				for (j = 0; j != 50; j++) PlantRandomFarmField(i);
+			}
+		}
+	}
+
 	return true;
 }