To reproduce the problem, make sure you have a GPG public key available, build and install GRUB:
grub-install --debug --debug-image="all" --pubkey=/boot/pubkey.gpg --modules="serial terminfo gzio search search_label search_fs_uuid search_fs_file linux vbe video_fb video mmap relocator verify gcry_rsa gcry_dsa gcry_sha256 hashsum gcry_sha1 mpi echo loadenv boottime" /dev/sda
Sign all the files in /boot/grub/* and reboot.

'make check' results identical before and after this change.

TESTED: In a QEMU VM using an i386 target.

	in separate root.

explicitly zeroing elements.
* grub-core/io/gzio.c (grub_gzio_open): Likewise.
* grub-core/io/lzopio.c (grub_lzopio_open): Remove explicit zeroing
of elements in a structure already allocated using grub_zalloc.
* grub-core/io/xzio.c (grub_xzio_open): Likewise.

	on it.

	* grub-core/bus/usb/usbhub.c (grub_usb_add_hub): Eliminate grub_min.
	(poll_nonroot_hub): Likewise.
	* grub-core/fs/affs.c (grub_affs_iterate_dir): Likewise.
	(grub_affs_label): Likewise.
	* grub-core/fs/btrfs.c (grub_btrfs_lzo_decompress): Likewise.
	* grub-core/fs/hfs.c (grub_hfs_dir): Likewise.
	(grub_hfs_label): Likewise.
	* grub-core/fs/hfsplus.c (grub_hfsplus_cmp_catkey): Likewise.
	* grub-core/fs/zfs/zfs.c (MIN): Remove.
	(zap_leaf_array_equal): Use grub_size. Remove MIN.
	(zap_leaf_array_get): Likewise.
	(dnode_get_path): Likewise.
	* grub-core/io/lzopio.c (grub_lzopio_read): Eliminate grub_min.
	* grub-core/io/xzio.c (grub_xzio_read): Likewise.
	* grub-core/script/execute.c (grub_script_break): Likewise.
	* grub-core/script/lexer.c (grub_script_lexer_record): Eliminate
	grub_max.
	* grub-core/script/yylex.l (grub_lexer_yyrealloc): Likewise.
	* include/grub/misc.h (grub_min): Removed.
	(grub_max): Likewise.

	guidelines.

	* grub-core/kern/dl.c (grub_dl_check_license): New function.
	(grub_dl_load_core): Use grub_dl_check_license.
	* include/grub/dl.h (GRUB_MOD_SECTION): New macro.
	(GRUB_MOD_LICENSE): Likewise.
	(GRUB_MOD_DUAL_LICENSE): Likewise.
	All modules updated.

(not_easily_seekable): ... this.  Update all users.

	used e.g. for initrd or modules. Moreover gzip handling of not
	easily seekable files is buggy. Disable unknown file size for now. May
	be inefficient but works.

	* grub-core/io/gzio.c (test_header): Always retrieve the file size.
	* grub-core/io/xzio.c (grub_xzio_open): Likewise.

	* grub-core/io/xzio.c: New file.
	* grub-core/lib/xzembed/xz.h: New file (from xembed).
	* grub-core/lib/xzembed/xz_config.h: Likewise.
	* grub-core/lib/xzembed/xz_dec_bcj.c: Likewise.
	* grub-core/lib/xzembed/xz_dec_lzma2.c: Likewise.
	* grub-core/lib/xzembed/xz_dec_stream.c: Likewise.
	* grub-core/lib/xzembed/xz_lzma2.h: Likewise.
	* grub-core/lib/xzembed/xz_private.h: Likewise.
	* grub-core/lib/xzembed/xz_stream.h: Likewise.
	* include/grub/file.h (grub_file_filter_id): New compression filter
	GRUB_FILE_FILTER_XZIO.