From: Jeff King <peff@peff.net>
Date: Mon, 14 May 2012 21:02:25 GMT
Subject: Re: [PATCH 1/2] drop length limitations on gecos-derived names and emails
Message-ID: <20120514210225.GA9677@sigill.intra.peff.net>
In-Reply-To: <20120514162824.GA24457@sigill.intra.peff.net>

On Mon, May 14, 2012 at 12:28:24PM -0400, Jeff King wrote:

> When we pull the user's name from the GECOS field of the
> passwd file (or generate an email address based on their
> username and hostname), we put the result into a
> static buffer. While it's extremely unlikely that anybody
> ever hit these limits (after all, in such a case their
> parents must have hated them), we still had to deal with the
> error cases in our code.
> 
> Converting these static buffers to strbufs lets us simplify
> the code and drop some error messages from the documentation
> that have confused some users.
> 
> Note that there is still one length limitation: the
> gethostname interface requires us to provide a static
> buffer, so we arbitrarily choose 1024 bytes for the
> hostname.
> 
> Signed-off-by: Jeff King <peff@peff.net>

Ick, there is something very wrong with this patch. While testing a
completely unrelated bug, I noticed that it set my name to "Jeff
KingJeff KingJeff King". Which, while a wonderful ego massage, is
probably excessive.

I'm sure the problem is the switch to strbuf's appending semantics
rather than strlcpy's overwriting semantics. I thought we were careful
not to bother re-run the gecos code if we had already gotten a name, but
obviously that is not the case in some code paths. I'll investigate.

-Peff