Cannot parse a pgn game not starting in initial position.

[ppipper]

I am not sure if its a bug. This game cannot be parsed unless you manually change move numbers to 1, 2, 3 etc.

Is this a bug?

(NOTE: move secuence is: 29. Rxb6+ Kxb6 30. Qb3+ Qb4 31. Qxb4# 1-0, but the html is converting it to 1.Rxb6...)

[Event "SampleSite"] [Site "?"] [Date "2008-01-04"] [Round "2"] [White "Zhou Jianchao"] [Black "Fidaeyee, H."] [Result "1-0"] [BlackElo "2074"] [FEN "1n1r3r/1k2q1p1/1bp1p2p/5p2/2Pp1B2/5QN1/5PPP/RR4K1 w - - 0 29"] [PlyCount "1"] [SetUp "1"] [SourceDate "2012.04.30"] [WhiteElo "2551"]

1. Rxb6+ Kxb6 30. Qb3+ Qb4 31. Qxb4# 1-0

[ryanhs]

hmm.. good case,

but as far as i know, in SetUp PGN, its always from 1. never find from 29, because software doesn't know movements from 1 - 28

[jhlywa]

I'll have to consult the PGN spec to see how to handle this.

[ppipper]

Thanks. By the way, the pgn text above can be pasted into some commercial programs (aquarium, chessbase) and it seems it is properly parsed, with the starting move on 29. Rxb6 and so on.

[ppipper]

well, in case it is present, SetUp tag must be "1".

This tag takes an integer that denotes the "set-up" status of the game. A value of "0" indicates that the game has started from the usual initial array. A value of "1" indicates that the game started from a set-up position; this position is given in the "FEN" tag pair. This tag must appear for a game starting with a set-up position. If it appears with a tag value of "1", a FEN tag pair must also appear.

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The point is that, having SetUp "1" and providing that FEN indicates the move number (say 29) when such PGN is parsed, the move info number shouldn't be lost, should it?

[jhlywa]

This was fixed in #150. I'll leave this issue open until I add test for it.

[sanichi]

I think the problem is that the regex that parses out the header_string in load_pgn(), assumes the game begins with move number 1. Specifically it is trying to match 1. (the digit 1 followed by any character) on line 1433. I guess, however, what was intended was: 1\. (the digit 1 followed by a full stop).

But, since game fragments (PGN with a FEN) don't always begin with move 1, or a move number which starts with 1, what should be here is [1-9]\d*\. (a positive integer followed by a full stop).

Anyway, I've tried this and it seems to work.