`gpart show` and secondary GPT header

[Alexander Best]

i have a question about gpart. when id do `gpart show ad0` i get the following
output:

=>       34  488394988  ad0  GPT  (233G)
         34   20971486    1  freebsd-swap  (10G)
   20971520  467423502    2  freebsd-ufs  (223G)

which is just what i want. however i'm a bit curious about the GPT header.
only the primary header from 0 - 33 is being shown. what about the
secondary/backup GPT header. is it present and just now shown by gpart or
doesn't it exist at all?

because in 7-STABLE e.g. `pt show ad0` also displays the secondary GPT header
at the end of the disk.

cheers.

...oh...and i'm running HEAD (r193846M). ;)