or a partition is larger than the slice.
Now `disklabel -Brw sdX auto' should fail properly on sliced disks
without partition of type 165, e.g., on zip disks with the factory
default formatting. Previously it set a bogus in-core label for
the compatibility slice and used this to corrupt the MBR (the slice
has offset 0 and size 0, but setting the label in effect corrupted
its size to nonzero).
`disklabel -Brw sdX auto' already failed properly on normally (not
dangerously dedicated) sliced disks _with_ partition of type 165,
because the compatibility slice has a nonzero offset so the MBR
remained inaccessible when the size was corrupted.
This bug only affected in-core labels. On-disk labels are checked
carefully when they read and written.