--- a/src/ai/api/ai_bridge.cpp	Thu Feb 28 01:04:50 2008 +0000
+++ b/src/ai/api/ai_bridge.cpp	Thu Feb 28 01:11:23 2008 +0000
@@ -24,9 +24,9 @@
 
 /* static */ bool AIBridge::BuildBridge(AIVehicle::VehicleType vehicle_type, BridgeID bridge_id, TileIndex start, TileIndex end)
 {
+	if (start == end) return false;
 	if (!::IsValidTile(start)) return false;
 	if (!::IsValidTile(end)) return false;
-	if (start == end) return false;
 	/* Not on one line */
 	if (TileX(start) != TileX(end) &&
 			TileY(start) != TileY(end)) return false;

--- a/src/ai/api/ai_road.cpp	Thu Feb 28 01:04:50 2008 +0000
+++ b/src/ai/api/ai_road.cpp	Thu Feb 28 01:11:23 2008 +0000
@@ -89,9 +89,9 @@
 
 /* static */ bool AIRoad::BuildRoad(TileIndex start, TileIndex end)
 {
+	if (start == end) return false;
 	if (!::IsValidTile(start)) return false;
 	if (!::IsValidTile(end)) return false;
-	if (start == end) return false;
 	/* Not on one line */
 	if (TileX(start) != TileX(end) &&
 			TileY(start) != TileY(end)) return false;
@@ -101,9 +101,9 @@
 
 /* static */ bool AIRoad::BuildRoadFull(TileIndex start, TileIndex end)
 {
+	if (start == end) return false;
 	if (!::IsValidTile(start)) return false;
 	if (!::IsValidTile(end)) return false;
-	if (start == end) return false;
 	/* Not on one line */
 	if (TileX(start) != TileX(end) &&
 			TileY(start) != TileY(end)) return false;
@@ -113,9 +113,9 @@
 
 /* static */ bool AIRoad::BuildRoadDepot(TileIndex tile, TileIndex front)
 {
+	if (tile == front) return false;
 	if (!::IsValidTile(tile)) return false;
 	if (!::IsValidTile(front)) return false;
-	if (tile == front) return false;
 
 	uint entrance_dir = (TileX(tile) == TileX(front)) ? (TileY(tile) < TileY(front) ? 1 : 3) : (TileX(tile) < TileX(front) ? 2 : 0);
 
@@ -124,9 +124,9 @@
 
 /* static */ bool AIRoad::BuildRoadStation(TileIndex tile, TileIndex front, bool truck, bool drive_through)
 {
+	if (tile == front) return false;
 	if (!::IsValidTile(tile)) return false;
 	if (!::IsValidTile(front)) return false;
-	if (tile == front) return false;
 
 	uint entrance_dir;
 	if (drive_through) {