Leonidas and ep

[Ferdy]

While checking those test games, winboard 4.6.2 flagged Leonidas of illegal move claim.

[pgn]
[Event "Computer Chess Game"]
[Site ""]
[Date "2015.05.18"]
[Round "82"]
[White "Leonidas 83"]
[Black "CDrill 1850"]
[Result "0-1"]
[TimeControl "40/60"]
[Annotator "9. +0.19 9... -0.20"]

1. d4 d6 2. Nf3 g6 3. g3 Bg7 4. Bg2 f5 5. O-O Nf6 6. c4 O-O 7. Nc3 Qe8 8.
b3 Na6 9. Bf4 {+0.19/9 1.0} Nh5 {-0.20/6 1.9} 10. Bg5 {+0.22/10 1.9} h6
{-0.20/6 1.9} 11. Bd2 {+0.17/9 1.3} Nf6 {-0.16/6 1.9} 12. Qc2 {+0.20/9 1.9}
e5 {-0.11/6 1.9} 13. dxe5 {+0.26/9 1.4} dxe5 {-0.10/7 1.7} 14. Rad1
{+0.17/8 1.2} e4 {-0.05/6 1.9} 15. Nd4 {+0.04/9 2.0} c5 {-0.08/6 1.9} 16.
Ndb5 {+0.21/10 2.0} Qc6 {-0.21/6 1.9} 17. Bf4 {+0.33/9 1.1} g5
{-0.05/6 1.9} 18. Rd6 {+0.27/9 2.0} Qe8 {-0.06/7 1.9} 19. Bd2 {+0.25/9 2.1}
Qf7 {-0.08/6 1.9} 20. Qc1 {+0.23/8 1.1} Ne8 {+0.78/7 1.9} 21. Rd8
{-0.52/10 2.1} Qe7 {+0.80/7 1.7} 22. Rxc8 {-0.53/11 2.1} Rxc8 {+0.75/7 1.0}
23. Nd5 {-0.56/10 1.8} Qd7 {+0.72/7 2.0} 24. Nxa7 {-0.51/10 2.1} Rd8
{+0.61/7 1.9} 25. Ba5 {-0.46/9 1.4} Nec7 {+0.54/6 1.9} 26. Rd1
{-0.53/9 1.7} Qf7 {+0.44/6 1.9} 27. Qd2 {-0.52/9 1.7} Be5 {+0.64/6 1.9} 28.
f4 {-0.46/9 1.6} exf3 {+0.81/7 1.8} 29. Bxf3 {-0.50/9 2.2} g4 {+0.85/6 2.0}
30. Bg2 {-0.37/9 2.1} Kh7 {+0.64/6 2.0} 31. Nb5 {-0.34/9 1.4} Rde8
{+0.58/5 2.0} 32. Ndxc7 {+0.04/9 2.3} Nxc7 {-0.09/7 2.0} 33. Nd6
{+0.11/10 2.4} Bxd6 {+0.67/7 1.0} 34. Qxd6 {+0.04/10 1.8} Rd8 {+0.63/7 2.1}
35. Qxd8 {+0.81/11 1.2} Rxd8 {+0.38/8 2.1} 36. Rxd8 {+1.19/12 2.7} Na6
{+0.25/8 1.5} 37. Ra8 {+1.31/11 1.2} Qg7 {+0.26/8 2.2} 38. Ra7
{+1.31/12 2.9} Qa1+ {+0.00/8 2.2} 39. Kf2 {+1.20/13 3} Nb4 {+0.00/8 1.4}
40. Rxb7+ {+1.09/12 3} Kg6 {+0.00/8 2.1} 41. Bxb4 {+1.09/12 1.1} cxb4
{+0.00/8 1.5} 42. Rb6+ {+0.22/11 1.7} Kg5 {+0.00/9 1.3} 43. h4+
{+1.94/12 1.1} gxh3 {+4.62/10 1.0}
{False illegal-move claim} 0-1
[/pgn]

[Evert]

It seems to be a bug with the evasion generator: it doesn't consider en-passant captures as legal evasions. I'll investigate, thanks!