From: David Michael <fedora.dm0@gmail.com>
Date: Sat, 05 Jan 2013 02:15:55 GMT
Subject: Re: [BUG/PATCH] setup: Copy an environment variable to avoid overwrites
Message-ID: <CAEvUa7mbs7rfGdfzbGb9p889K7GUbXFg9TUcFWFYKt8+8AKCiQ@mail.gmail.com>
In-Reply-To: <7vsj6gqvhc.fsf@alter.siamese.dyndns.org>

Hi,

On Fri, Jan 4, 2013 at 8:17 PM, Junio C Hamano <gitster@pobox.com> wrote:
> In fact,
>
>     http://pubs.opengroup.org/onlinepubs/9699919799/functions/getenv.html
>
> says that only setenv(), unsetenv() and putenv() may invalidate
> previous return values.  Note that getenv() is not listed as a
> function that is allowed to break return values from a previous call
> to getenv().

Before I sent the e-mail, I checked that very page to be sure I wasn't
entirely insane.  Specifically, the second paragraph begins with:

> The string pointed to may be overwritten by a subsequent call to getenv(), [...]

I read that line as confirmation that this is indeed acceptably
standard behavior.  Even the getenv man page on my Fedora workstation
says:

> The string pointed to by the return value of getenv() may be statically allocated, and can be modified by a subsequent call to getenv(), putenv(3), setenv(3), or unsetenv(3).

Am I misinterpreting these statements?

Thanks.

David