From c70cefc848dede2c1954d7d823f373434fc06843 Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Sat, 7 Jun 2025 08:53:42 -0700
Subject: [PATCH] [position] Pop captured piece from CapturesList on unmake

---
 position/src/position.rs          | 7 ++++++-
 position/src/position/captures.rs | 4 ++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/position/src/position.rs b/position/src/position.rs
index bac5b01..e674b81 100644
--- a/position/src/position.rs
+++ b/position/src/position.rs
@@ -189,7 +189,12 @@ impl Position {
 
         let unmake_result = self.board.unmake_move(&last_move_record);
 
-        if unmake_result.is_err() {
+        if unmake_result.is_ok() {
+            if let Some(capture) = last_move_record.captured_piece {
+                let popped_piece = self.captures.pop(last_move_record.color);
+                debug_assert_eq!(Some(capture), popped_piece);
+            }
+        } else {
             self.moves.push(last_move_record);
         }
 
diff --git a/position/src/position/captures.rs b/position/src/position/captures.rs
index ddd9dac..f879c5b 100644
--- a/position/src/position/captures.rs
+++ b/position/src/position/captures.rs
@@ -17,6 +17,10 @@ impl CapturesList {
         self.0[color as usize].push(piece);
     }
 
+    pub fn pop(&mut self, color: Color) -> Option<Piece> {
+        self.0[color as usize].pop()
+    }
+
     pub fn is_empty(&self) -> bool {
         self.0.iter().all(Vec::is_empty)
     }