From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 08 Dec 2008 02:47:21 GMT
Subject: Re: [PATCH] fetch-pack: Avoid memcpy() with src==dst
Message-ID: <7viqpvbcxy.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <1228596609-12720-1-git-send-email-trast@student.ethz.ch>

Thomas Rast <trast@student.ethz.ch> writes:

> memcpy() may only be used for disjoint memory areas, but when invoked
> from cmd_fetch_pack(), we have my_args == &args.  (The argument cannot
> be removed entirely because transport.c invokes with its own
> variable.)

It makes me wonder if it might be a better fix to abolish the use of file
scoped global "args" and pass a pointer to "struct fetch_pack_args"
throughout the callchain instead.

In the current code, cmd_fetch_pack() is the only caller that passes &args
to this function, but it is not so implausible to have a future callchain
that makes two calls to cmd_fetch_pack(), perhaps implementing some sort
of alias to fetch from multiple places, would horribly break without such
a fix, because cmd_fetch_pack() assumes that args is in its pristine
state.

I'll apply this to 'maint' and merge it up, because the patch is
independent of the above issue.

Thanks.