From mboxrd@z Thu Jan  1 00:00:00 1970
From: Junio C Hamano <gitster@pobox.com>
Subject: Re: concurrent fetches to update same mirror
Date: Wed, 05 Jan 2011 15:29:47 -0800
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Cc: Shawn Pearce <spearce@spearce.org>,
	Neal Kreitzinger <neal@rsss.com>, git@vger.kernel.org
To: Jeff King <peff@peff.net>
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Jeff King <peff@peff.net> writes:

> Interestingly, in the case of ref _creation_, not update, like this:
>
>   mkdir repo && cd repo && git init
>   git remote add origin some-remote-repo-that-takes-a-few-seconds
>   xterm -e 'git fetch -v; read' & xterm -e 'git fetch -v; read'
>
> then both will happily update, the second one overwriting the results of
> the first. It seems in the case of locking a ref which previously didn't
> exist, we don't enforce that it still doesn't exist.

We probably should, especially when there is no --force or +prefix is
involved.