problem with _arguments

[Adam Spiers <adam@xxxxxxxxxx>]

I'm trying to write a very simple completion for a function, with the
following requirements:

 - the function has one optional option '-l' with no parameter
 - the first parameter can't be completed
 - subsequent parameters are files

AFAICS from the docs, the completion function should be something
like:

_foo () {
  _arguments \
    '-l[message for option]' \
    ':description for first param: ' \
    '*:description for files:_files'
}

But with the latest CVS:

$ foo -<TAB>
$ foo -
---- description for first param

What am I doing wrong, or is it a bug?