Emergency Gaviota black en passant release

niklasf · Oct 7, 2015 · 1383e5f · 1383e5f
1 parent 4cec6a1
commit 1383e5f
Show file tree

Hide file tree

Showing 4 changed files with 23 additions and 3 deletions.
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -6,6 +6,14 @@ is more important to get things right, than to be consistent with previous
 versions. Use this changelog to see what changed in a new release, because this
 might include API breaking changes.
 
+New in v0.12.2
+--------------
+
+Bugfixes:
+
+* Some Gaviota probe results were incorrect for positions where black could
+  capture en passant.
+
 New in v0.12.1
 --------------
 

diff --git a/chess/__init__.py b/chess/__init__.py
@@ -20,7 +20,7 @@
 
 __email__ = "[email protected]"
 
-__version__ = "0.12.1"
+__version__ = "0.12.2"
 
 import copy
 import re

diff --git a/chess/gaviota.py b/chess/gaviota.py
@@ -1863,7 +1863,7 @@ def _setup_tablebase(self, req):
             req.is_reversed = True
             req.egkey = black_letters + white_letters
             req.white_piece_squares = [flip_ns(s) for s in req.black_squares]
-            req.white_piece_tyoes = req.black_types
+            req.white_piece_types = req.black_types
             req.black_piece_squares = [flip_ns(s) for s in req.white_squares]
             req.black_piece_types = req.white_types
 
@@ -1907,7 +1907,8 @@ def egtb_get_dtm(self, req):
             capturer_b = 0
             xed = 0
 
-            if (req.side == 0):
+            # Flip for move generation.
+            if req.side == 0:
                 xs = list(req.white_piece_squares)
                 xp = list(req.white_piece_types)
                 ys = list(req.black_piece_squares)
@@ -1945,6 +1946,12 @@ def egtb_get_dtm(self, req):
                         xs[i] = req.epsq
                         removepiece(ys, yp, j)
 
+                        # Flip back.
+                        if req.side == 1:
+                            xs, ys = ys, xs
+                            xp, yp = yp, xp
+
+                        # Make subrequest.
                         subreq = Request(xs, xp, ys, yp, opp(req.side), NOSQUARE)
                         try:
                             epscore = self._tb_probe(subreq)

diff --git a/data/endgame-dm-4.epd b/data/endgame-dm-4.epd
@@ -4,6 +4,11 @@
 
 1k1K4/8/8/pP6/8/8/8/8 w - a6 dm 0;
 4k3/8/8/2p5/8/6P1/6K1/8 w - c6 dm 0;
+7K/k7/8/Pp6/8/8/8/8 w - - dm -15;
+7K/k7/8/Pp6/8/8/8/8 w - b6 dm 0;
+8/8/8/8/pP6/8/K7/7k b - - dm -15;
+8/8/8/8/8/1p6/K7/7k w - - dm 0;
+8/8/8/8/pP6/8/K7/7k b - b3 dm 0;
 8/7k/8/8/3p4/1K6/2P5/8 b - - dm -19;
 
 # Long endgames.