Re: [RFC PATCH] commit -v: strip diffs and submodule shortlogs from the commit message

From: Jeff King <peff@peff.net>
Date: Nov 17, 2013, 09:09 UTC
Message-ID: <20131117090935.GC17016@sigill.intra.peff.net>
In-Reply-To: <5287F735.3030306@web.de>

Show 14 quoted lines

> diff --git a/builtin/commit.c b/builtin/commit.c
> index 6ab4605..091a6e7 100644
> --- a/builtin/commit.c
> +++ b/builtin/commit.c
> @@ -1602,9 +1602,9 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
> 
>  	/* Truncate the message just before the diff, if any. */
>  	if (verbose) {
> -		p = strstr(sb.buf, "\ndiff --git ");
> -		if (p != NULL)
> -			strbuf_setlen(&sb, p - sb.buf + 1);
> +		p = strstr(sb.buf, wt_status_diff_divider);
> +		if ((p != NULL) && (p > sb.buf) && (p[-1] == '\n'))
> +			strbuf_setlen(&sb, p - sb.buf);

I think your check for a preceding newline is too strict. If I delete everything before the scissor line (e.g., because I am trying to abort the commit), we should still remove the diff. With your patch, we do not, and a commit message consisting solely of the diff.

So I think you want:

  if (p && (p == sb.buf || p[-1] == '\n'))

> +	fprintf(s->fp, _("# The diff below will be removed when keeping the previous line.\n"));

I found this hard to parse, I think because of the "keeping" (why would I not keep it?), and because you are talking about lines above and below. It is not as accurate to say:

  # ------------------ >8 --------------------
  # Everything below this line will be removed.

because it is technically the line above that is the cutoff. But I think the meaning is clear, and it is simpler to parse.

I do think it would be simpler with a single line. I know handling the i18n was a question there, but I think we should be fine as long as we check for the exact bytes we wrote. Surely gettext can do something like:

  magic = _("# Everything below this line will be removed");
  fprintf(fh, "%s", magic);
  ...
  p = strstr(magic);

I don't know what guarantees on string lifetime gettext gives us, but the worst case is that we simply strdup the result.

I suppose it's possible that the translated string could have utf8 with multiple representations, and the user's editor normalizes the text in a different way than we wrote it when it saves the result. I don't know if that is worth caring about or not; it seems kind of insane.

-Peff