Re: [PATCH 04/44] wrapper: add function to compare strings with different NUL termination

From: Martin Ågren <martin.agren@gmail.com>
Date: May 13, 2020, 19:32 UTC
Message-ID: <CAN0heSqBeW86yyH6vUATX+Az=4qG0gW_QhgsbWnTKXX=Q9hiig@mail.gmail.com>
In-Reply-To: <20200513005424.81369-5-sandals@crustytoothpaste.net>

On Wed, 13 May 2020 at 02:56, brian m. carlson <sandals@crustytoothpaste.net> wrote:

Show 25 quoted lines

> diff --git a/git-compat-util.h b/git-compat-util.h
> index 8ba576e81e..6503deb171 100644
> --- a/git-compat-util.h
> +++ b/git-compat-util.h
> @@ -868,6 +868,8 @@ char *xgetcwd(void);
>  FILE *fopen_for_writing(const char *path);
>  FILE *fopen_or_warn(const char *path, const char *mode);
>
> +int xstrncmpz(const char *s, const char *t, size_t len);
> +
>  /*
>   * FREE_AND_NULL(ptr) is like free(ptr) followed by ptr = NULL. Note
>   * that ptr is used twice, so don't pass e.g. ptr++.
> diff --git a/wrapper.c b/wrapper.c
> index 3a1c0e0526..15a09740e7 100644
> --- a/wrapper.c
> +++ b/wrapper.c
> @@ -430,6 +430,18 @@ int xmkstemp(char *filename_template)
>         return fd;
>  }
>
> +/*
> + * Like strncmp, but only return zero if s is NUL-terminated and exactly len
> + * characters long.  If it is not, consider it greater than t.
> + */

I think this comment would be easier to find in the .h file.

And since I'm already commenting...

Show 11 quoted lines

> +int xstrncmpz(const char *s, const char *t, size_t len)
> +{
> +       int res = strncmp(s, t, len);
> +       if (res)
> +               return res;
> +       return s[len] == '\0' ? 0 : 1;
> +}
> +
>  /* Adapted from libiberty's mkstemp.c. */
>
>  #undef TMP_MAX

It's not entirely obvious from the context, but this function is inserted between some "tmp" stuff and some other "tmp" stuff. I don't think we need to bikeshed its exact home, but maybe "close to other string stuff", or at least not in the middle of the "tmp" section.

Martin