Re: [PATCH 05/11] Remove va_copy at MSVC because there are va_copy.

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Aug 17, 2009, 16:49 UTC
Message-ID: <alpine.DEB.1.00.0908171840450.4991@intel-tinevez-2-302>
In-Reply-To: <1250525040-5868-1-git-send-email-lznuaa@gmail.com>

Hi,

On Tue, 18 Aug 2009, Frank Li wrote:

> MSVs have not implemented va_copy. remove va_copy at MSVC environment.
> It will malloc buffer each time.
> 
> Signed-off-by: Frank Li <lznuaa@gmail.com>

How about this instead?

	Work around Microsoft Visual C++ not having va_copy()

	In winansi.c, Git wants to know the length of the formatted string 
	so it can allocate enough space for it.  But Microsoft Visual C++
	does not have va_copy(), so we have to guess.

The problem is the guessing part:

Show 15 quoted lines

> diff --git a/compat/winansi.c b/compat/winansi.c
> index 9217c24..6091138 100644
> --- a/compat/winansi.c
> +++ b/compat/winansi.c
> @@ -310,9 +314,13 @@ static int winansi_vfprintf(FILE *stream, const char *format, va_list list)
>  	if (!console)
>  		goto abort;
>  
> +#ifndef _MSC_VER 
>  	va_copy(cp, list);
>  	len = vsnprintf(small_buf, sizeof(small_buf), format, cp);
>  	va_end(cp);
> +#else
> +	len= sizeof(small_buf) ;
> +#endif

small_buf only is 256 bytes. How do you want to make sure that the subsequent vsnprintf() is not writing outside of the buffer?

Also, you still miss a space between "len" and "=".

Ciao, Dscho