Re: [PATCH 03/14] Define SNPRINTF_SIZE_CORR=1 for Microsoft Visual C++

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 21, 2009, 20:55 UTC
Message-ID: <7vr5v4dgz0.fsf@alter.siamese.dyndns.org>
In-Reply-To: <c899c41fdccfdc94ae294f1a50895ba0290a1ec3.1250860247.git.mstormo@gmail.com>

Marius Storm-Olsen <mstormo@gmail.com> writes:

> From: Frank Li <lznuaa@gmail.com>
>
> The Microsoft C runtime's vsnprintf function does not add NUL at
> the end of the buffer.

This contradicts the way I read the comment in compat/snprintf.c from f4626df (Add target architecture MinGW., 2007-12-01).

As far as I can see, the correction is about the meaning of the size parameter to the function, namely, that a broken implementation may mistakenly think that it was told the maximum length of the meat of the string to write, and it is allowed to append a NUL beyond the limit, when the caller actually is telling it the size of the buffer.

So if my reading is correct, it is not about "does not add NUL at the end" at all; it is "adds NUL beyond the end of given output buffer."