1 files changed, 13 insertions, 1 deletions
diff --git a/game.adb b/game.adb
index cd403e2..b30731c 100644
--- a/game.adb
+++ b/game.adb
@@ -21,7 +21,7 @@ package body Game is
 	function Next(game: in out T_Game) return Boolean is
 		new_head: constant T_Position := Next_Head(game);
 	begin
-		if not In_Border(game, new_head) then
+		if not In_Border(game, new_head) or else In_Body(game, new_head) then
 			return false;
 		end if;
 		Enqueue(game.snake, new_head);
@@ -94,4 +94,16 @@ package body Game is
 		return pos.y >= 1 and pos.y <= game.height and pos.x >= 1 and pos.x <= game.width;
 	end In_Border;
 
+	function In_Body(game: T_Game; pos: T_Position) return Boolean is
+		cursor: T_List := game.snake.front;
+	begin
+		while cursor /= null loop
+			if pos = cursor.data then
+				return true;
+			end if;
+			cursor := cursor.next;
+		end loop;
+		return false;
+	end In_Body;
+
 end Game;