Index: src/viewport.cpp
===================================================================
--- src/viewport.cpp	(wersja 23123)
+++ src/viewport.cpp	(kopia robocza)
@@ -2109,11 +2109,13 @@
 			switch (_thd.place_mode & HT_DRAG_MASK) {
 				case HT_RECT:
 					new_drawstyle = HT_RECT;
+					x1 = min(x1, MapMaxX() * TILE_SIZE - _thd.new_size.x);
+					y1 = min(y1, MapMaxY() * TILE_SIZE - _thd.new_size.y);
 					break;
 				case HT_POINT:
 					new_drawstyle = HT_POINT;
-					x1 += TILE_SIZE / 2;
-					y1 += TILE_SIZE / 2;
+					x1 = min(x1 + TILE_SIZE / 2, MapSizeX() * TILE_SIZE - _thd.new_size.x);
+					y1 = min(y1 + TILE_SIZE / 2, MapSizeY() * TILE_SIZE - _thd.new_size.y);
 					break;
 				case HT_RAIL:
 					/* Draw one highlighted tile in any direction */