widget class is Array

[Denis-de-Bernardy]

when using a callback with a static class in a widget, the widget's class is set to Array. e.g.:

class foo
{
  function bar($args)
  {
    echo $args['before_widget'];
    echo 'foobar widget';
    echo $args['after_widget'];
  }
}

when using:

register_sidebar_widget('FooBar', array('foo', 'bar'));

then $argsbefore_widget? returns:

<li id="name" class="widget Array">

rather than something like:

<li id="name" class="widget foo_bar">

[Nazgul]

#4910 appears to be a duplicate, but as that one is fixed, I'll close this one.