Merge pull request #168 from pleco-rs/copilot/fix-iterative-parallel-mvv-lva-panic

Fix index out of bounds panic in iterative_parallel_mvv_lva when depth >= 10

Author: chase-manning

pleco/src/bots/iterative_parallel_mvv_lva.rs

@@ -35,7 +35,8 @@ pub fn iterative_deepening(board: &mut Board, max_depth: u16) -> BitMove {
         // clone the board
         let mut b = board.shallow_clone();
 
-        let returned_b_move = jamboree(&mut b, alpha, beta, i, PLYS_SEQ[i as usize]);
+        let plys_idx = std::cmp::min(i as usize, PLYS_SEQ.len() - 1);
+        let returned_b_move = jamboree(&mut b, alpha, beta, i, PLYS_SEQ[plys_idx]);
         if i >= 2 {
             if returned_b_move.score > beta {
                 beta = INF_V;

pleco/src/bots/mod.rs

@@ -142,4 +142,11 @@ mod tests {
             JamboreeSearcher::best_move(b2, 5)
         );
     }
+
+    #[test]
+    fn iterative_searcher_depth_10() {
+        let b = Board::from_fen("1k6/R7/8/7B/7P/8/5Q2/B3K2R w K - 11 47").unwrap();
+        // Should not panic with depth >= PLYS_SEQ length
+        let _best = IterativeSearcher::best_move(b, 10);
+    }
 }