Re: [PATCH v10 03/20] pkt-line: add gentle version of packet_write

> packet_write calls write_or_die, which dies with a sigpipe even if
> calling code has explicitly blocked that signal.
>
> Add packet_write_gently and packet_flush_gently, which don't.  Soon,
> we will use this for communication with git index-helper, which, being
> merely an optimization, should be permitted to die without disrupting
> clients.
>
> Signed-off-by: David Turner <dturner@twopensource.com>
> ---

>  pkt-line.c | 18 ++++++++++++++++++
>  pkt-line.h |  2 ++
>  2 files changed, 20 insertions(+)
>
> diff --git a/pkt-line.c b/pkt-line.c
> index 62fdb37..f964446 100644
> --- a/pkt-line.c
> +++ b/pkt-line.c
> @@ -91,6 +91,12 @@ void packet_flush(int fd)
>  	write_or_die(fd, "0000", 4);
>  }
>  
> +int packet_flush_gently(int fd)
> +{
> +	packet_trace("0000", 4, 1);
> +	return write_in_full(fd, "0000", 4) != 4;
> +}
> +
>  void packet_buf_flush(struct strbuf *buf)
>  {
>  	packet_trace("0000", 4, 1);
> @@ -130,6 +136,18 @@ void packet_write(int fd, const char *fmt, ...)
>  	write_or_die(fd, buf.buf, buf.len);
>  }
>  
> +int packet_write_gently(int fd, const char *fmt, ...)
> +{
> +	static struct strbuf buf = STRBUF_INIT;
> +	va_list args;
> +
> +	strbuf_reset(&buf);
> +	va_start(args, fmt);
> +	format_packet(&buf, fmt, args);
> +	va_end(args);
> +	return write_in_full(fd, buf.buf, buf.len) != buf.len;
> +}
> +
>  void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
>  {
>  	va_list args;
> diff --git a/pkt-line.h b/pkt-line.h
> index 3cb9d91..deffcb5 100644
> --- a/pkt-line.h
> +++ b/pkt-line.h
> @@ -20,7 +20,9 @@
>   * side can't, we stay with pure read/write interfaces.
>   */
>  void packet_flush(int fd);
> +int packet_flush_gently(int fd);
>  void packet_write(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
> +int packet_write_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3)));
>  void packet_buf_flush(struct strbuf *buf);
>  void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3)));