RDoc doesn't make a link for inner module inclusion.

I found that RDoc doesn't make a link for inner module inclusion as
follows.

% cat x.rb 
module X
  module MMM
  end
  class C
    include MMM
  end
end

% rdoc -q x.rb 
% w3m -dump doc/classes/X/C.html
X::C ^(Class)

In:      x.rb  
Parent:  Object

Included Modules

MMM

[Validate]

% grep MMM doc/classes/X/C.html
                    <span class="include-name">MMM</span>
% grep -i '<a' doc/classes/X/C.html
                <a href="../../files/x_rb.html">
  <p><small><a href="http://validator.w3.org/check/referer">[Validate]</a></small></p>

MMM should be a link to doc/classes/X/MMM.html.
-- 
Tanaka Akira