From: Marco Costalba <mcostalba@gmail.com>
Date: Sun, 4 Dec 2011 11:24:15 +0000 (+0100)
Subject: Fix disambiguation bug in move_to_san()
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=11a79809767e60897e0b015651db30ce1d36b69a;hp=5b8ca1eee77b736c35b418b1cb11da9fc66f83e0

Fix disambiguation bug in move_to_san()

A pinned piece cannot move and so does not play any role
in SAN disambiguation.

Reported by Steven Edwards.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
---

diff --git a/src/move.cpp b/src/move.cpp
index 1a312cbc..d079ee7b 100644
--- a/src/move.cpp
+++ b/src/move.cpp
@@ -106,6 +106,10 @@ const string move_to_san(Position& pos, Move m) {
           {
               sq = pop_1st_bit(&attackers);
 
+              // Pinned pieces are not included in the possible sub-set
+              if (!pos.pl_move_is_legal(make_move(sq, to), pos.pinned_pieces()))
+                  continue;
+
               if (file_of(sq) == file_of(from))
                   ambiguousFile = true;