Changes
If the documentation is accurate, this will use the namespace part of pageName first and fallback to Template if one isn't present, which is what we want.
title = mw.title.new( mw.ustring.sub(pageName, 2) );
else
title = mw.title.new( pageName ); if title.namespace == 0 then title = mw.title.makeTitle( , 'Template', pageName ); end
end