Re: [PATCH] Add the --submodule option to the diff option family

[Junio C Hamano <gitster@pobox.com>]

Jens Lehmann <Jens.Lehmann@web.de> writes:

> When you use the option --submodule=left-right-log you can see the submodule
> summaries inlined in the diff, instead of not-quite-helpful SHA-1 pairs.
>
> The format imitates what "git submodule summary" shows.
>
> To do that, <path>/.git/objects/ is added to the alternate object
> databases (if that directory exists).
>
> This option was requested by Jens Lehmann at the GitTogether in Berlin.
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
> ---

Thanks.

I have four patches queued on js/diff-verbose-submodule topic and I think
this corresponds to the first three, correct?

> diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
> index 9276fae..99cb517 100644
> --- a/Documentation/diff-options.txt
> +++ b/Documentation/diff-options.txt
> @@ -87,6 +87,13 @@ endif::git-format-patch[]
>  	Show only names and status of changed files. See the description
>  	of the `--diff-filter` option on what the status letters mean.
>
> +--submodule[=<format>]::
> +	Chose the output format for submodule differences. <format> can be one of
> +	'short' and 'left-right-log'. 'short' is the default value for this
> +	option and and shows pairs of commit names. 'left-right-log' lists the
> +	commits in that commit range like the 'summary' option of
> +	linkgit:git-submodule[1] does.
> +

Well, while left-right-log may be logically the most correct name for this
option, I think it is too long to be practical.  Because it is not like we
would want to have an option to have full log there when we are showing
"diff", I think it would make sense to making left-right-log the default
when "--submodule" (without format specification) is given, and possibly
give "--submodule=log" as the synonym for this format.

After all, if you do not give --submodule, we will give the traditional
short format, no?

> diff --git a/diff.c b/diff.c
> index c719ce2..8af1ae2 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -2771,6 +2783,10 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
>  		DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
>  	else if (!strcmp(arg, "--ignore-submodules"))
>  		DIFF_OPT_SET(options, IGNORE_SUBMODULES);
> +	else if (!prefixcmp(arg, "--submodule=")) {
> +		if (!strcmp(arg + 12, "left-right-log"))
> +			DIFF_OPT_SET(options, SUBMODULE_LEFT_RIGHT_LOG);
> +	}

I do not see --submodule (without "=<format>") supported here as the
documentation claims, but this is the logical place to do so.

> diff --git a/submodule.c b/submodule.c
> new file mode 100644
> index 0000000..206386f
> --- /dev/null
> +++ b/submodule.c
> @@ -0,0 +1,112 @@
> +...
> +void show_submodule_summary(FILE *f, const char *path,
> +		unsigned char one[20], unsigned char two[20],
> +		const char *del, const char *add, const char *reset)
> +{
> ...
> +	fwrite(sb.buf, sb.len, 1, f);
> +
> +	if (!message) {
> +		while ((commit = get_revision(&rev))) {
> + ...
> +		}
> +		clear_commit_marks(left, ~0);
> +		clear_commit_marks(right, ~0);
> +	}
> +}

I thought we had strbuf_release(&sb) here...  Where did it go?