Duplicate GUIDs by default

All Safe-Redirect-Manager posts have matching GUIDs. I assume this is because the post type doesn't support 'title'. 

Aside from the philosophical ramifications of non-unique "unique IDs", this is problematic for my team because we use the <a href="http://crowdfavorite.com/ramp/">RAMP content deployment plugin</a> in our publishing workflow. RAMP relies on post GUIDs to determine whether a post exists on both staging and production. Posts with duplicate GUIDs are extremely problematic.

I've worked around the problem for now by generating a unique-ish GUID (using timestamp + author ID) in the filter_post_type_link function:

    public function filter_post_type_link( $permalink, $post ) {
		if ( $this->redirect_post_type != $post->post_type )
			return $permalink;

        // Handle initial GUID generation
        if ('' == $post->post_name) 
         {
          return home_url('safe-redirect-rule-' . gmmktime() . '-' . $post->post_author);
        } 

		// We can't do anything to provide a permalink 
		// for regex enabled redirects.
		if ( get_post_meta( $post->ID, $this->meta_key_enable_redirect_from_regex, true ) )
			return $permalink;

		// We can't do anything if there is a wildcard in the redirect from
		$redirect_from = get_post_meta( $post->ID, $this->meta_key_redirect_from, true );
		if ( false !== strpos( $redirect_from, '*' ) )
			return $permalink;

		return home_url( $redirect_from );
	  }
    }