Function run_diff

diff.c:5024–5076

}

static void run_diff(struct diff_filepair *p, struct diff_options *o)
{
	const struct external_diff *pgm = external_diff();
	struct strbuf msg;
	struct diff_filespec *one = p->one;
	struct diff_filespec *two = p->two;
	const char *name;
	const char *other;
	const char *attr_path;

	name  = one->path;
	other = (strcmp(name, two->path) ? two->path : NULL);
	attr_path = name;
	if (o->prefix_length)
		strip_prefix(o->prefix_length, &name, &other);

	if (!o->flags.allow_external)
		pgm = NULL;

	if (DIFF_PAIR_UNMERGED(p)) {
		run_diff_cmd(pgm, name, NULL, attr_path,
			     NULL, NULL, NULL, o, p);
		return;
	}

	diff_fill_oid_info(one, o->repo->index);
	diff_fill_oid_info(two, o->repo->index);

	if (!pgm &&
	    DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
	    (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
		/*
		 * a filepair that changes between file and symlink
		 * needs to be split into deletion and creation.
		 */
		struct diff_filespec *null = alloc_filespec(two->path);
		run_diff_cmd(NULL, name, other, attr_path,
			     one, null, &msg,
			     o, p);
		free(null);
		strbuf_release(&msg);

		null = alloc_filespec(one->path);
		run_diff_cmd(NULL, name, other, attr_path,
			     null, two, &msg, o, p);
		free(null);
	}
	else
		run_diff_cmd(pgm, name, other, attr_path,
			     one, two, &msg, o, p);

	strbuf_release(&msg);
}

static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
			 struct diffstat_t *diffstat)