using verify over stdin

[Justin Karneges]

>   gpg  --enable-special-filenames --verify - '-&5' <sig 5<data
>
> With --enable-special-filenames you may - at most places - give an
> open file descriptor number prefixed with "-&" instead of a filename.
> "-" is the usual abbreviation for '-&0' or '-&1' depending on context.

This works:

gpg  --enable-special-filenames --verify - '-&5'

but these don't:
gpg  --enable-special-filenames --verify '-&0' '-&5'
gpg  --enable-special-filenames --verify '-&5' -
gpg  --enable-special-filenames --verify '-&5' '-&0'

It looks like you can only use a special fd for the second arg.  The first arg 
must be a file or '-'.  Is this a bug?

-Justin