Interesting, it only seems to happen for VFAT, not for any other file system.
It seems likely that the bug is actually in libparted:
$ sudo /lib/udev/udisks-part-id /dev/sdb
device=0xe56e00' for devpath=/sys/devices/pci0000:00/0000:00:1d.7/usb1/1-8/1-8.2/1-8.2:1.0/host13/target13:0:0/13:0:0:0/block/sdb
Expected `linear' in UDISKS_DM_TARGETS_TYPE=`(null)'
using device_file=/dev/sdb syspath=/sys/devices/pci0000:00/0000:00:1d.7/usb1/1-8/1-8.2/1-8.2:1.0/host13/target13:0:0/13:0:0:0/block/sdb, offset=0 ao=0 and number=0 for /dev/sdb
Entering MS-DOS parser (offset=0, size=1028653056)
MSDOS_MAGIC found
looking at part 0 (offset 0, size 0, type 0x00)
new part entry
looking at part 1 (offset 0, size 0, type 0x00)
new part entry
looking at part 2 (offset 0, size 0, type 0x00)
new part entry
looking at part 3 (offset 0, size 0, type 0x00)
new part entry
Exiting MS-DOS parser
MSDOS partition table detected
UDISKS_PARTITION_TABLE=1
UDISKS_PARTITION_TABLE_SCHEME=mbr
UDISKS_PARTITION_TABLE_COUNT=0
Interesting, it only seems to happen for VFAT, not for any other file system.
It seems likely that the bug is actually in libparted:
$ sudo /lib/udev/ udisks- part-id /dev/sdb /sys/devices/ pci0000: 00/0000: 00:1d.7/ usb1/1- 8/1-8.2/ 1-8.2:1. 0/host13/ target13: 0:0/13: 0:0:0/block/ sdb DM_TARGETS_ TYPE=`( null)' file=/dev/ sdb syspath= /sys/devices/ pci0000: 00/0000: 00:1d.7/ usb1/1- 8/1-8.2/ 1-8.2:1. 0/host13/ target13: 0:0/13: 0:0:0/block/ sdb, offset=0 ao=0 and number=0 for /dev/sdb PARTITION_ TABLE=1 PARTITION_ TABLE_SCHEME= mbr PARTITION_ TABLE_COUNT= 0
device=0xe56e00' for devpath=
Expected `linear' in UDISKS_
using device_
Entering MS-DOS parser (offset=0, size=1028653056)
MSDOS_MAGIC found
looking at part 0 (offset 0, size 0, type 0x00)
new part entry
looking at part 1 (offset 0, size 0, type 0x00)
new part entry
looking at part 2 (offset 0, size 0, type 0x00)
new part entry
looking at part 3 (offset 0, size 0, type 0x00)
new part entry
Exiting MS-DOS parser
MSDOS partition table detected
UDISKS_
UDISKS_
UDISKS_