Found possible error in gnuchess pawn movement

[Brian Wightman]

Hi,

First of all for clarity, a pawn can ONLY attack diagonally correct? Or
is there a rule I have never been told...

I was playing the gnuchess engine and black moved its pawn diagonally to
the right and the white pawn originally to its right was removed from
the board.

ex.
before
~ ~ ~ ~
~ p P ~
~ ~ ~ ~
~ ~ ~ ~

after
~ ~ ~ ~
~ ~ ~ ~
~ ~ p ~
~ ~ ~ ~

Attached is the game.log of GNU Chess 5.07 and before/after xboard
screenschots
Thanks,
Brian Wightman

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nf3 Nf6 3. e3 Nc6 4. Bd3 Bg4 5. Qe2 e5 6. O-O e4 7. Ba6 bxa6 8.
Qxa6 Nb4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. e4 d5 2. d4 dxe4 3. Nc3 Nf6 4. Bb5+ Bd7 5. d5 Bxb5 6. Nxb5 Na6 7. c4 c6 8.
dxc6 Qxd1+ 9. Kxd1 bxc6 10. Nd4 Rd8 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. e4 d5 2. d4 dxe4 3. Nc3 Nf6 4. Bb5+ Bd7 5. d5 Bxb5 6. Nxb5 Na6 7. c4 c6 8.
dxc6 Qxd1+ 9. Kxd1 bxc6 10. Nd4 Rd8 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. e4 d5 2. d4 dxe4 3. Nc3 Nf6 4. Bb5+ Bd7 5. d5 Bxb5 6. Nxb5 Na6 7. c4 c6 8.
dxc6 Qxd1+ 9. Kxd1 bxc6 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. e4 d5 2. d4 dxe4 3. Nc3 Nf6 4. Bb5+ Bd7 5. d5 Bxb5 6. Nxb5 Na6 7. c4 c6 8.
dxc6 Qxd1+ 9. Kxd1 bxc6 10. Nc3 Nb4 11. Nge2 O-O-O 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. e4 d5 2. d4 dxe4 3. Nc3 Nf6 4. Bb5+ Bd7 5. d5 Bxb5 6. Nxb5 Na6 7. c4 c6 8.
dxc6 Qxd1+ 9. Kxd1 bxc6 10. Nc3 Nb4 11. Nge2 O-O-O 12. Bd2 Ng4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. e4 d5 2. d4 dxe4 3. Nc3 Nf6 4. Bb5+ Bd7 5. d5 Bxb5 6. Nxb5 Na6 7. c4 c6 8.
dxc6 Qxd1+ 9. Kxd1 bxc6 10. Nc3 Nb4 11. Nge2 O-O-O 12. Bd2 Ng4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. e4 d5 2. d4 dxe4 3. Nc3 Nf6 4. Bb5+ Bd7 5. d5 Bxb5 6. Nxb5 Na6 7. c4 c6 8.
dxc6 Qxd1+ 9. Kxd1 bxc6 10. Nc3 Nb4 11. Nge2 O-O-O 12. Bd2 Ng4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. c4 e5 2. Nc3 Nc6 3. Nf3 Nf6 4. e4 Bb4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. c4 e5 2. Nc3 Nc6 3. Nf3 Nf6 4. e4 Bb4 5. d3 O-O 6. a3 Bxc3+ 7. Bd2 Bxb2 8.
Ra2 Bd4 9. Be2 d6 10. Nh4 Ng4 11. Bxg4 Qxh4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. Qb5 a6 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. b4 Nxb4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. dxe5 Nxe5 7. Qd4 Nc6 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. dxe5 Nxe5 7. Qd4 Nc6 8.
Qf4 Bd6 9. Qg5 Nb4 10. e4 Nxc2+ 11. Kd1 Nxa1 12. Qxg7 Rg8 13. Qh6 Nxe4 14. f3
Nf2+ 15. Ke1 Nxh1 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. dxe5 Nxe5 7. Qd4 Nc6 8.
Qf4 Bd6 9. Qg5 Nb4 10. e4 Nxc2+ 11. Kd1 Nxa1 12. Qxg7 Rg8 13. Qh6 Nxe4 14. f3
Nf2+ 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. dxe5 Nxe5 7. Qd4 Nc6 8.
Qf4 Bd6 9. Qg5 Nb4 10. e4 Nxc2+ 11. Kd1 Nxa1 12. Qxg7 Rg8 13. Qh6 Nxe4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. dxe5 Nxe5 7. Qd4 Nc6 8.
Qf4 Bd6 9. Qg5 Nb4 10. e4 Nxc2+ 11. Kd1 Nxa1 12. Qxg7 Rg8 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. dxe5 Nxe5 7. Qd4 Nc6 8.
Qf4 Bd6 9. Qg5 Nb4 10. e4 Nxc2+ 11. Kd1 Nxa1 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. dxe5 Nxe5 7. Qd4 Nc6 8.
Qf4 Bd6 9. Qg5 Nb4 10. e4 Nxc2+ 11. Kd1 Nxa1 12. Qh4 dxe4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. dxe5 Nxe5 7. Qd4 Nc6 8.
Qf4 Bd6 9. Qg5 Nb4 10. e4 Nxc2+ 11. Kd1 Nxa1 12. Qh4 dxe4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. dxe5 Nxe5 7. Qd4 Nc6 8.
Qf4 Bd6 9. Qg5 Nb4 10. e4 Nxc2+ 11. Kd1 Nxa1 12. Qh4 dxe4 

[Event ""]
[Site ""]
[Date "2006.05.25"]
[Round ""]
[White ""]
[Black "GNU Chess 5.07"]
[WhiteELO "0"]
[BlackELO "0"]
[Result ""]

1. d4 d5 2. Nc3 Nf6 3. e3 Nc6 4. Nge2 h5 5. Qd3 e5 6. dxe5 Nxe5 7. Qd4 Nc6 8.
Qf4 Bd6 9. Qg5 Nb4 10. e4 Nxc2+ 11. Kd1 Nxa1