Re: [PATCH v8 8/8] diff: teach diff to display submodule difference with an inline diff

> diff --git a/diff.h b/diff.h
> index ea5aba668eaa..192c0eedd0ff 100644
> --- a/diff.h
> +++ b/diff.h
> @@ -112,6 +112,7 @@ enum diff_words_type {
>  enum diff_submodule_format {
>  	DIFF_SUBMODULE_SHORT = 0,
>  	DIFF_SUBMODULE_LOG,
> +	DIFF_SUBMODULE_INLINE_DIFF,

>  };
>  
>  struct diff_options {
> diff --git a/submodule.c b/submodule.c
> index 7108b4786bc1..cecd3cd98de4 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -435,6 +435,68 @@ void show_submodule_summary(FILE *f, const char *path,
>  	clear_commit_marks(right, ~0);
>  }
>  
> +void show_submodule_inline_diff(FILE *f, const char *path,
> +		const char *line_prefix,
> +		struct object_id *one, struct object_id *two,
> +		unsigned dirty_submodule, const char *meta,
> +		const char *del, const char *add, const char *reset,
> +		const struct diff_options *o)
> +{
> +	const struct object_id *old = &empty_tree_oid, *new = &empty_tree_oid;
> +	struct commit *left = NULL, *right = NULL;
> +	struct strbuf submodule_dir = STRBUF_INIT;
> +	struct child_process cp = CHILD_PROCESS_INIT;
> +
> +	show_submodule_header(f, path, line_prefix, one, two, dirty_submodule,
> +			      meta, reset, &left, &right);
> +
> +	/* We need a valid left and right commit to display a difference */
> +	if (!(left || is_null_oid(one)) ||
> +	    !(right || is_null_oid(two)))
> +		goto done;
> +
> +	if (left)
> +		old = one;
> +	if (right)
> +		new = two;
> +
> +	fflush(f);
> +	cp.git_cmd = 1;
> +	cp.dir = path;
> +	cp.out = dup(fileno(f));
> +	cp.no_stdin = 1;
> +
> +	/* TODO: other options may need to be passed here. */
> +	argv_array_pushl(&cp.args, "diff");