Found by: Coverity scan.

* include/grub/fs.h (grub_fs_dir_hook_t): New type.
(struct grub_fs.dir): Add hook_data argument.

Update all implementations and callers.

* include/grub/arc/arc.h (grub_arc_iterate_devs_hook_t): New type.
(grub_arc_iterate_devs): Add hook_data argument.
* include/grub/ata.h (grub_ata_dev_iterate_hook_t): New type.
(struct grub_ata_dev.iterate): Add hook_data argument.
* include/grub/device.h (grub_device_iterate_hook_t): New type.
(grub_device_iterate): Add hook_data argument.
* include/grub/disk.h (grub_disk_dev_iterate_hook_t): New type.
(struct grub_disk_dev.iterate): Add hook_data argument.
(grub_disk_dev_iterate): Likewise.
* include/grub/gpt_partition.h (grub_gpt_partition_map_iterate):
Likewise.
* include/grub/msdos_partition.h (grub_partition_msdos_iterate):
Likewise.
* include/grub/partition.h (grub_partition_iterate_hook_t): New
type.
(struct grub_partition_map.iterate): Add hook_data argument.
(grub_partition_iterate): Likewise.
* include/grub/scsi.h (grub_scsi_dev_iterate_hook_t): New type.
(struct grub_scsi_dev.iterate): Add hook_data argument.

Update all callers.

	put explicit "/" for empty path.
	(wildcard_expand): Improve dprintf.

	Reported by: Robert Mabee.

	* grub-core/commands/wildcard.c (isregexop): Add "|+{}[]?".
	(make_regex): Escape "|+{}[]". Transform '?' to '.?'.
	(split_path): Trigger expansion on '?'.
	(unescape): New function.
	(wildcard_expand): Unescape parts copied without globbing.
	* grub-core/script/execute.c (wildcard_escape): Escape '?'.
	(grub_script_arglist_to_argv): Don't unescape expansions.

	* grub-core/commands/wildcard.c (wildcard_escape): Moved from here ...
	* grub-core/script/execute.c (wildcard_escape): .. to here.
	Don't escape dot.
	* grub-core/commands/wildcard.c (wildcard_unescape): Moved from here ...
	* grub-core/script/execute.c (wildcard_unescape): .. to here.
	Don't escape dot.
	* grub-core/script/execute.c (gettext_append): Always escape.
	(grub_script_arglist_to_argv): Always handle escaping/unescaping.
	* grub-core/script/yylex.l: Don't cut away the escaping.
	* tests/grub_script_echo1.in: Add tests with wildcard.

	value rather than let it uninited.

	(wildcard_expand): Don't expand to non-existing files, expand with
	suffix and not attempt to expand if not needed.

	without explicit device.
	(wildcard_expand): Don't add explicit device if not already present.
	* tests/grub_script_echo1.in: Add a new expansion test.

	* grub-core/hook/datehook.c (grub_datetime_names): Make const.
	(grub_read_hook_datetime): Return const char *.
	* grub-core/kern/env.c (grub_env_get): Return const char *. All users
	updated.
	* grub-core/normal/datetime.c (grub_weekday_names): Make const.
	Mark for gettext.
	(grub_get_weekday_name): Return const char *. Call gettext.
	* grub-core/script/argv.c (grub_script_argv_append): Receive const
	char * and len as the argument. All users updated.
	(grub_script_argv_split_append): Receive const char *.
	* include/grub/datetime.h (grub_get_weekday_name): Update proto.
	* include/grub/env.h (grub_env_get): Likewise.
	(grub_env_read_hook_t): Return const char *.
	* include/grub/script_sh.h (grub_script_argv_append): Update proto.
	(grub_script_argv_split_append): Likewise.

	pointer checks before calling grub_free().
	* grub-core/commands/wildcard.c (match_devices): Likewise.
	* grub-core/commands/wildcard.c (match_files): Likewise.
	* grub-core/fs/cpio.c (grub_cpio_dir): Likewise.
	* grub-core/fs/cpio.c (grub_cpio_open): Likewise.
	* grub-core/fs/udf.c (grub_udf_read_block): Likewise.
	* grub-core/fs/xfs.c (grub_xfs_read_block): Likewise.
	* grub-core/loader/efi/chainloader.c (grub_cmd_chainloader): Likewise.
	* grub-core/normal/cmdline.c (grub_cmdline_get): Likewise.
	* grub-core/script/yylex.l (grub_lexer_unput): Likewise.
	* grub-core/video/readers/jpeg.c (grub_video_reader_jpeg): Likewise.
	* grub-core/video/readers/png.c (grub_png_output_byte): Likewise.

	(wildcard_expand): Don't stop on nonregexp parts after regexp ones since
	it truncates the output.
	Reported by: Ximin Luo.

	variable.
	* grub-core/commands/wildcard.c (match_files): Likewise.

	grub_free.