From: Marco Costalba <mcostalba@gmail.com>
Date: Sat, 23 Jul 2011 11:52:49 +0000 (+0100)
Subject: Use a circular buffer to keep track of setup states
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=5f7eb20090ccd04b2a7d439b723ed58591dcc7e8;hp=5f7eb20090ccd04b2a7d439b723ed58591dcc7e8

Use a circular buffer to keep track of setup states

This fixes a regression on real games due to the fact that
we have some mismatches:

    history[st->gamePly - i] != stp->key

when st->gamePly - i == 0,this is due to a nasty bug I have
introduced when using std::vector<> as StateInfo backup. The
point is that StateInfo keeps inside a pointer to the previous
StateInfo in a kind of linked list. But when std::vector<> is
resized reallocates a larger chunk of memory and moves the
data there so these pointers became stale.

This patch fixes the issue.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
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