Function prep_exclude

dir.c:1649–1800

* Loads the per-directory exclude list for the substring of base * which has a char length of baselen. */

 * which has a char length of baselen.
 */
static void prep_exclude(struct dir_struct *dir,
			 struct index_state *istate,
			 const char *base, int baselen)
{
	struct exclude_list_group *group;
	struct pattern_list *pl;
	struct exclude_stack *stk = NULL;
	struct untracked_cache_dir *untracked;
	int current;

	group = &dir->internal.exclude_list_group[EXC_DIRS];

	/*
	 * Pop the exclude lists from the EXCL_DIRS exclude_list_group
	 * which originate from directories not in the prefix of the
	 * path being checked.
	 */
	while ((stk = dir->internal.exclude_stack) != NULL) {
		if (stk->baselen <= baselen &&
		    !strncmp(dir->internal.basebuf.buf, base, stk->baselen))
			break;
		pl = &group->pl[dir->internal.exclude_stack->exclude_ix];
		dir->internal.exclude_stack = stk->prev;
		dir->internal.pattern = NULL;
		free((char *)pl->src); /* see strbuf_detach() below */
		clear_pattern_list(pl);
		free(stk);
		group->nr--;
	}

	/* Skip traversing into sub directories if the parent is excluded */
	if (dir->internal.pattern)
		return;

	/*
	 * Lazy initialization. All call sites currently just
	 * memset(dir, 0, sizeof(*dir)) before use. Changing all of
	 * them seems lots of work for little benefit.
	 */
	if (!dir->internal.basebuf.buf)
		strbuf_init(&dir->internal.basebuf, PATH_MAX);

	/* Read from the parent directories and push them down. */
	current = stk ? stk->baselen : -1;
	strbuf_setlen(&dir->internal.basebuf, current < 0 ? 0 : current);
	if (dir->untracked)
		untracked = stk ? stk->ucd : dir->untracked->root;
	else
		untracked = NULL;

	while (current < baselen) {
		const char *cp;
		struct oid_stat oid_stat;

		CALLOC_ARRAY(stk, 1);
		if (current < 0) {
			cp = base;
			current = 0;