Function check_to_create

apply.c:3929–3973

#define EXISTS_IN_INDEX_AS_ITA 3

static int check_to_create(struct apply_state *state,
			   const char *new_name,
			   int ok_if_exists)
{
	struct stat nst;

	if (state->check_index && (!ok_if_exists || !state->cached)) {
		int pos;

		pos = index_name_pos(state->repo->index, new_name, strlen(new_name));
		if (pos >= 0) {
			struct cache_entry *ce = state->repo->index->cache[pos];

			/* allow ITA, as they do not yet exist in the index */
			if (!ok_if_exists && !(ce->ce_flags & CE_INTENT_TO_ADD))
				return EXISTS_IN_INDEX;

			/* ITA entries can never match working tree files */
			if (!state->cached && (ce->ce_flags & CE_INTENT_TO_ADD))
				return EXISTS_IN_INDEX_AS_ITA;
		}
	}

	if (state->cached)
		return 0;

	if (!lstat(new_name, &nst)) {
		if (S_ISDIR(nst.st_mode) || ok_if_exists)
			return 0;
		/*
		 * A leading component of new_name might be a symlink
		 * that is going to be removed with this patch, but
		 * still pointing at somewhere that has the path.
		 * In such a case, path "new_name" does not exist as
		 * far as git is concerned.
		 */
		if (has_symlink_leading_path(new_name, strlen(new_name)))
			return 0;

		return EXISTS_IN_WORKTREE;
	} else if (!is_missing_file_error(errno)) {
		return error_errno("%s", new_name);
	}
	return 0;
}

static void prepare_symlink_changes(struct apply_state *state, struct patch *patch)
{