Source Reference:

• Component: bbPress :: bbp-topic

  File: /bbp-includes/bbp-topic-template.php :: Trac Source Line: 1722

  			// No link
  			if ( bbp_get_view_all() )
  				$retval .= " $extra";
  
  			// Link
  			else
  				$retval .= " <a href='" . esc_url( bbp_add_view_all( bbp_get_topic_permalink( $topic_id ), true ) ) . "'>$extra</a>";
  		}
  
  		return apply_filters( 'bbp_get_topic_replies_link', $retval, $topic_id );
  	}
  
  /**
   * Output total reply count of a topic
   *
   * @since bbPress (r2485)
   *
   * @param int $topic_id Optional. Topic id
   * @uses bbp_get_topic_reply_count() To get the topic reply count
   */