Re: [PATCH 1/2] fetch: avoid calling write_or_die()

[Duy Nguyen <pclouds@gmail.com>]

On Sun, Mar 3, 2019 at 11:55 PM Jeff King <peff@peff.net> wrote:
>
> The write_or_die() function has one quirk that a caller might not
> expect: when it sees EPIPE from the write() call, it translates that
> into a death by SIGPIPE. This doesn't change the overall behavior (the
> program exits either way), but it does potentially confuse test scripts
> looking for a non-signal exit code.
>
> Let's switch away from using write_or_die() in a few code paths, which
> will give us more consistent exit codes. It also gives us the
> opportunity to write more descriptive error messages, since we have
> context that write_or_die() does not.
>
> Note that this won't do much by itself, since we'd typically be killed
> by SIGPIPE before write_or_die() even gets a chance to do its thing.
> That will be addressed in the next patch.
>
> Signed-off-by: Jeff King <peff@peff.net>
> ---
>  fetch-pack.c | 9 ++++++---
>  pkt-line.c   | 6 ++++--
>  2 files changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/fetch-pack.c b/fetch-pack.c
> index 812be15d7e..dca249e9d7 100644
> --- a/fetch-pack.c
> +++ b/fetch-pack.c
> @@ -191,8 +191,10 @@ static void send_request(struct fetch_pack_args *args,
>         if (args->stateless_rpc) {
>                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
>                 packet_flush(fd);
> -       } else
> -               write_or_die(fd, buf->buf, buf->len);
> +       } else {
> +               if (write_in_full(fd, buf->buf, buf->len) < 0)
> +                       die_errno("unable to write to remote");

maybe _() these strings.

> +       }
>  }
>
>  static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
> @@ -1163,7 +1165,8 @@ static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
>
>         /* Send request */
>         packet_buf_flush(&req_buf);
> -       write_or_die(fd_out, req_buf.buf, req_buf.len);
> +       if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
> +               die_errno("unable to write request to remote");
>
>         strbuf_release(&req_buf);
>         return ret;
> diff --git a/pkt-line.c b/pkt-line.c
> index d4b71d3e82..093b2f3976 100644
> --- a/pkt-line.c
> +++ b/pkt-line.c
> @@ -88,13 +88,15 @@ static void packet_trace(const char *buf, unsigned int len, int write)
>  void packet_flush(int fd)
>  {
>         packet_trace("0000", 4, 1);
> -       write_or_die(fd, "0000", 4);
> +       if (write_in_full(fd, "0000", 4) < 0)
> +               die_errno("unable to write flush packet");
>  }
>
>  void packet_delim(int fd)
>  {
>         packet_trace("0001", 4, 1);
> -       write_or_die(fd, "0001", 4);
> +       if (write_in_full(fd, "0001", 4) < 0)
> +               die_errno("unable to write delim packet");
>  }
>
>  int packet_flush_gently(int fd)
> --
> 2.21.0.675.g01c085a870
>


-- 
Duy