From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.1) Gecko/20021003 Description of problem: While playing chess and you produce a ceratin move when a pawn captures another pawn by a "back" capture the computer fails to execute another move. Detailed reproduction: you have a 2 white pawns and 1 black pawn on squares that connect to each other like this: Open | Open Blck | Whte Whte | Open and you move the furthest pawn to capture black Whte | Open Cap | Open Whte | Open the computer (black) does not execute additional moves, black flag falls, and game is stuck. Version-Release number of selected component (if applicable): gnuchess-5.02-9 How reproducible: Always Steps to Reproduce: 1.play chess 2.produce scheme above 3.capture black pawn with "back" capture Actual Results: Game freezes and you can no longer move. Expected Results: Game should continue so that I can finally beat this hard ass computer competition. Additional info: Hope this helps. It would ne nice to choose diffetent levels of play, but I guess that is featurezilla.
Created attachment 91112 [details] test case
Technically, the term for a "back" pawn capture as described, is "en passant". The bug is that illegal en passant captures are not always detected correctly. xboard does not catch all illegal moves, and gnuchess may interpret moves which are legal syntatically but illegal semantically as bad commands, a response which is ambiguous to xboard. http://mail.gnu.org/archive/html/bug-gnu-chess/2002-03/msg00002.html Test case (save this in bug.pgn and then run xboard -lgf bug.pgn): 1. d4 Nf6 2. Nc3 e6 3. Nf3 Bb4 4. a3 Bxc3+ 5. bxc3 O-O 6. e3 d5 7. Ne5 Ne4 8. Ng4 Nxc3 9. Qd3 Ne4 10. c4 Nc6 11. Bb2 f5 12. Ne5 Nxe5 13. dxe5 f4 14. exd6 *
waiting for an upstream fix