Subject: Re: [PATCH] compat/snprintf.c: handle snprintf's that always return the # chars transmitted

From: Johannes Sixt <[email-masked]>
Date: Thu, 21 Aug 2008 10:06:31 +0200

Brandon Casey schrieb:
> Some platforms provide a horribly broken snprintf. More broken than the
> platforms that return -1 when there is too little space in the target buffer
> for the formatted string. Some platforms provide an snprintf which _always_
> returns the number of characters transmitted to the buffer, regardless of
> whether there was enough space or not.
...
> diff --git a/compat/snprintf.c b/compat/snprintf.c
> index 580966e..357e733 100644
> --- a/compat/snprintf.c
> +++ b/compat/snprintf.c
> @@ -17,6 +17,8 @@ int git_vsnprintf(char *str, size_t maxsize, const char *format, va_list ap)
>  
>  	if (maxsize > 0) {
>  		ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, ap);
> +		if (ret == maxsize-1)
> +			ret = -1;
>  		/* Windows does not NUL-terminate if result fills buffer */
>  		str[maxsize-1] = 0;
>  	}
> @@ -34,6 +36,8 @@ int git_vsnprintf(char *str, size_t maxsize, const char *format, va_list ap)
>  			break;
>  		s = str;
>  		ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, ap);
> +		if (ret == maxsize-1)
> +			ret = -1;
>  	}
>  	free(s);
>  	return ret;

This looks good, and it passes the test suite on MinGW. Hence:

Acked-by: Johannes Sixt <[email-masked]>

-- Hannes