From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Sun, 28 Nov 2021 19:31:31 +0000 (+0100)
Subject: Fix disambiguation of special moves
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=08e9de6eff8f2a4b79b52cfc1f9051f3457e42bc;p=fairystockfish.git

Fix disambiguation of special moves

Closes #408.
---

diff --git a/setup.py b/setup.py
index a243af9..fe882e6 100644
--- a/setup.py
+++ b/setup.py
@@ -39,7 +39,7 @@ pyffish_module = Extension(
     sources=sources,
     extra_compile_args=args)
 
-setup(name="pyffish", version="0.0.66",
+setup(name="pyffish", version="0.0.67",
       description="Fairy-Stockfish Python wrapper",
       long_description=long_description,
       long_description_content_type="text/markdown",
diff --git a/src/apiutil.h b/src/apiutil.h
index 0cd7bc7..f316cca 100644
--- a/src/apiutil.h
+++ b/src/apiutil.h
@@ -206,8 +206,11 @@ inline Disambiguation disambiguation_level(const Position& pos, Move m, Notation
     while (b)
     {
         Square s = pop_lsb(b);
-        if (   pos.pseudo_legal(make_move(s, to))
-               && pos.legal(make_move(s, to))
+        // Construct a potential move with identical special move flags
+        // and only a different "from" square.
+        Move testMove = Move(m ^ make_move(from, to) ^ make_move(s, to));
+        if (      pos.pseudo_legal(testMove)
+               && pos.legal(testMove)
                && !(is_shogi(n) && pos.unpromoted_piece_on(s) != pos.unpromoted_piece_on(from)))
             others |= s;
     }
diff --git a/src/pyffish.cpp b/src/pyffish.cpp
index a80b216..71d6ec1 100644
--- a/src/pyffish.cpp
+++ b/src/pyffish.cpp
@@ -54,7 +54,7 @@ void buildPosition(Position& pos, StateListPtr& states, const char *variant, con
 }
 
 extern "C" PyObject* pyffish_version(PyObject* self) {
-    return Py_BuildValue("(iii)", 0, 0, 66);
+    return Py_BuildValue("(iii)", 0, 0, 67);
 }
 
 extern "C" PyObject* pyffish_info(PyObject* self) {
diff --git a/test.py b/test.py
index edcd37b..cb580b5 100644
--- a/test.py
+++ b/test.py
@@ -512,6 +512,13 @@ class TestPyffish(unittest.TestCase):
         result = sf.get_san("shogi", SHOGI, "f1e2", False, sf.NOTATION_SHOGI_HODGES_NUMBER)
         self.assertEqual(result, "G49-58")
 
+        # Disambiguation of promotion moves
+        fen = "p1ksS/n1n2/4P/5/+L1K1+L[] b - - 3 9"
+        result = sf.get_san("kyotoshogi", fen, "c4b2+", False, sf.NOTATION_SHOGI_HODGES_NUMBER)
+        self.assertEqual(result, "N32-44+")
+        result = sf.get_san("kyotoshogi", fen, "a4b2+", False, sf.NOTATION_SHOGI_HODGES_NUMBER)
+        self.assertEqual(result, "N52-44+")
+
         fen = "lnsgkgsnl/1r5b1/pppppp1pp/6p2/9/2P6/PP1PPPPPP/1B5R1/LNSGKGSNL w -"
         result = sf.get_san("shogi", fen, "b2h8", False, sf.NOTATION_SHOGI_HODGES)
         self.assertEqual(result, "Bx2b=")
@@ -648,6 +655,13 @@ class TestPyffish(unittest.TestCase):
         result = sf.get_san("seirawan", fen, "h1e1e")
         self.assertEqual(result, "O-O/Eh1")
 
+        # Disambiguation only when necessary
+        fen = "rnbqkb1r/ppp1pppp/5n2/3p4/3P4/5N2/PPP1PPPP/RNBQKB1R[EHeh] w KQABCDEFHkqabcdefh - 2 3"
+        result = sf.get_san("seirawan", fen, "b1d2e")
+        self.assertEqual(result, "Nd2/E")
+        result = sf.get_san("seirawan", fen, "b1d2")
+        self.assertEqual(result, "Nbd2")
+
     def test_get_san_moves(self):
         UCI_moves = ["e2e4", "e7e5", "g1f3", "b8c6h", "f1c4", "f8c5e"]
         SAN_moves = ["e4", "e5", "Nf3", "Nc6/H", "Bc4", "Bc5/E"]