properly fix max_depth

src/logic/future_moves.rs

@@ -55,7 +55,7 @@ impl FutureMoves {
             .filter(|&idx| self.is_connected_to_root(idx)) // put here so this will not extend needlessly before prunes
             .collect();
 
-        for i in self.current_depth..=self.max_depth {
+        for i in (self.current_depth + 1)..=self.max_depth {
             next_nodes = next_nodes
                 .into_iter()
                 .progress_with_style(
@@ -425,4 +425,26 @@ mod tests {
 
         assert_ne!(futm.arena[2].i, 1234, "dummy value still exists");
     }
+
+    #[test]
+    fn expand_layer_test() {
+        let mut futm = FutureMoves::new(Piece::Black, 1, 1);
+        futm.arena.push(Move {
+            i: 0,
+            j: 0,
+            board: Board::new().starting_pos(),
+            winner: Winner::None,
+            parent: None,
+            children: Vec::new(),
+            value: 0,
+            self_value: 0,
+            color: Piece::Black,
+            lazy_children: false,
+        });
+
+        futm.current_root = Some(0);
+
+        futm.extend_layers();
+        assert_eq!(futm.arena_len(), 5);
+    }
 }