From: Junio C Hamano <junkio@cox.net>
Date: Sat, 28 Apr 2007 22:47:21 GMT
Subject: Re: [PATCH 1/5] Make xstrndup common
Message-ID: <7vslaki0au.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <46339819.8030007@freedesktop.org>

Josh Triplett <josh@freedesktop.org> writes:

> Daniel Barkalow wrote:
>> It was implemented in commit.c; move it with the other x memory functions.
> [...]
>> +static inline char *xstrndup(const char *str, int len)
>> +{
>> +	char *ret = xmalloc(len + 1);
>> +	memcpy(ret, str, len);
>> +	ret[len] = '\0';
>> +	return ret;
>> +}
>> +
>
> I don't know if it matters, but this definition of xstrndup, like the version
> in commit.c, doesn't match the definition of strndup.  strndup duplicates a
> string, copying up to n characters or the length of the string.  This xstrndup
> always copies n characters, reading past the end of the string if it doesn't
> have at least n characters.

Very well caught indeed, thanks.  In the original context in
commit.c, this function is always given length computed by
inspecting the source text by the caller, so the code was
correct, but if we are making it available as a general utility
routine, we probably cannot depend on that assumption anymore.