From aad9105426b86e84937d300af6bbf16e4fb90511 Mon Sep 17 00:00:00 2001
From: H.G.Muller <hgm@hgm-xboard.(none)>
Date: Sat, 20 Dec 2025 13:40:08 +0100
Subject: [PATCH] Fix CECP notation for Fischer castling

FSF was using UCI's KxR notation even in CECP, where it has to be O-O(-O).
---
 src/uci.cpp |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/src/uci.cpp b/src/uci.cpp
index 584977a..fa916ae 100644
--- a/src/uci.cpp
+++ b/src/uci.cpp
@@ -534,6 +534,8 @@ string UCI::move(const Position& pos, Move m) {
   string move = (type_of(m) == DROP ? UCI::dropped_piece(pos, m) + (CurrentProtocol == USI ? '*' : '@')
                                     : UCI::square(pos, from)) + UCI::square(pos, to);
 
+  if(CurrentProtocol == XBOARD && type_of(m) == CASTLING && pos.is_chess960()) move = to > from ? "O-O" : "O-O-O";
+
   // Wall square
   if (pos.walling() && CurrentProtocol == XBOARD)
       move += "," + UCI::square(pos, to) + UCI::square(pos, gating_square(m));
-- 
1.7.0.4