Function read_attr_from_index

attr.c:791–839

}

static struct attr_stack *read_attr_from_index(struct index_state *istate,
					       const char *path, unsigned flags)
{
	struct attr_stack *stack = NULL;
	char *buf;
	unsigned long size;
	int sparse_dir_pos = -1;

	if (!istate)
		return NULL;

	/*
	 * When handling sparse-checkouts, .gitattributes files
	 * may reside within a sparse directory. We distinguish
	 * whether a path exists directly in the index or not by
	 * evaluating if 'pos' is negative.
	 * If 'pos' is negative, the path is not directly present
	 * in the index and is likely within a sparse directory.
	 * For paths not in the index, The absolute value of 'pos'
	 * minus 1 gives us the position where the path would be
	 * inserted in lexicographic order within the index.
	 * We then subtract another 1 from this value
	 * (sparse_dir_pos = -pos - 2) to find the position of the
	 * last index entry which is lexicographically smaller than
	 * the path. This would be the sparse directory containing
	 * the path. By identifying the sparse directory containing
	 * the path, we can correctly read the attributes specified
	 * in the .gitattributes file from the tree object of the
	 * sparse directory.
	 */
	if (!path_in_cone_mode_sparse_checkout(path, istate)) {
		int pos = index_name_pos_sparse(istate, path, strlen(path));

		if (pos < 0)
			sparse_dir_pos = -pos - 2;
	}

	if (sparse_dir_pos >= 0 &&
	    S_ISSPARSEDIR(istate->cache[sparse_dir_pos]->ce_mode) &&
	    !strncmp(istate->cache[sparse_dir_pos]->name, path, ce_namelen(istate->cache[sparse_dir_pos]))) {
		const char *relative_path = path + ce_namelen(istate->cache[sparse_dir_pos]);
		stack = read_attr_from_blob(istate, &istate->cache[sparse_dir_pos]->oid, relative_path, flags);
	} else {
		buf = read_blob_data_from_index(istate, path, &size);
		if (buf)
			stack = read_attr_from_buf(buf, size, path, flags);
	}
	return stack;
}

static struct attr_stack *read_attr(struct index_state *istate,
				    const struct object_id *tree_oid,