static char *pprint_rename(const char *a, const char *b)
{
	const char *old = a;
	const char *new = b;
	struct strbuf name;
	int pfx_length, sfx_length;
	int len_a = strlen(a);
	int len_b = strlen(b);
	int a_midlen, b_midlen;
	int qlen_a = quote_c_style(a, NULL, NULL, 0);
	int qlen_b = quote_c_style(b, NULL, NULL, 0);

	strbuf_init(&name, 0);
	if (qlen_a || qlen_b) {
		quote_c_style(a, &name, NULL, 0);
		strbuf_addstr(&name, " => ");
		quote_c_style(b, &name, NULL, 0);
		return strbuf_detach(&name, NULL);
	}

	/* Find common prefix */
	pfx_length = 0;
	while (*old && *new && *old == *new) {
		if (*old == '/')
			pfx_length = old - a + 1;
		old++;
		new++;
	}

	/* Find common suffix */
	old = a + len_a;
	new = b + len_b;
	sfx_length = 0;
	while (a <= old && b <= new && *old == *new) {
		if (*old == '/')
			sfx_length = len_a - (old - a);
		old--;
		new--;
	}

	/*
	 * pfx{mid-a => mid-b}sfx
	 * {pfx-a => pfx-b}sfx
	 * pfx{sfx-a => sfx-b}
	 * name-a => name-b
	 */
	a_midlen = len_a - pfx_length - sfx_length;
	b_midlen = len_b - pfx_length - sfx_length;
	if (a_midlen < 0)
		a_midlen = 0;
	if (b_midlen < 0)
		b_midlen = 0;

	strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
	if (pfx_length + sfx_length) {
		strbuf_add(&name, a, pfx_length);
		strbuf_addch(&name, '{');
	}
	strbuf_add(&name, a + pfx_length, a_midlen);
	strbuf_addstr(&name, " => ");
	strbuf_add(&name, b + pfx_length, b_midlen);
	if (pfx_length + sfx_length) {
		strbuf_addch(&name, '}');
		strbuf_add(&name, a + len_a - sfx_length, sfx_length);
	}
	return strbuf_detach(&name, NULL);
}
Unknown