bbp_pre_get_posts_normalize_forum_visibility( WP_Query $posts_query = null )

function bbp_pre_get_posts_normalize_forum_visibility( $posts_query = null ) {

	// Bail if all forums are explicitly allowed
	if ( true === apply_filters( 'bbp_include_all_forums', false, $posts_query ) ) {
		return;
	}

	// Bail if $posts_query is not an object or of incorrect class
	if ( !is_object( $posts_query ) || !is_a( $posts_query, 'WP_Query' ) ) {
		return;
	}

	// Get query post types array .
	$post_types = (array) $posts_query->get( 'post_type' );

	// Forums
	if ( bbp_get_forum_post_type() === implode( '', $post_types ) ) {

		// Prevent accidental wp-admin post_row override
		if ( is_admin() && isset( $_REQUEST['post_status'] ) ) {
			return;
		}

		/** Default ***********************************************************/

		// Get any existing post status
		$post_stati = $posts_query->get( 'post_status' );

		// Default to public status
		if ( empty( $post_stati ) ) {
			$post_stati = array( bbp_get_public_status_id() );

		// Split the status string
		} elseif ( is_string( $post_stati ) ) {
			$post_stati = explode( ',', $post_stati );
		}

		/** Private ***********************************************************/

		// Remove bbp_get_private_status_id() if user is not capable
		if ( ! current_user_can( 'read_private_forums' ) ) {
			$key = array_search( bbp_get_private_status_id(), $post_stati );
			if ( !empty( $key ) ) {
				unset( $post_stati[$key] );
			}

		// ...or add it if they are
		} else {
			$post_stati[] = bbp_get_private_status_id();
		}

		/** Hidden ************************************************************/

		// Remove bbp_get_hidden_status_id() if user is not capable
		if ( ! current_user_can( 'read_hidden_forums' ) ) {
			$key = array_search( bbp_get_hidden_status_id(), $post_stati );
			if ( !empty( $key ) ) {
				unset( $post_stati[$key] );
			}

		// ...or add it if they are
		} else {
			$post_stati[] = bbp_get_hidden_status_id();
		}

		// Add the statuses
		$posts_query->set( 'post_status', array_unique( array_filter( $post_stati ) ) );
	}

	// Topics Or Replies
	if ( array_intersect( array( bbp_get_topic_post_type(), bbp_get_reply_post_type() ), $post_types ) ) {

		// Get forums to exclude
		$forum_ids = bbp_exclude_forum_ids( 'meta_query' );

		// Bail if no forums to exclude
		if ( ! array_filter( $forum_ids ) ) {
			return;
		}

		// Get any existing meta queries
		$meta_query   = (array) $posts_query->get( 'meta_query', array() );

		// Add our meta query to existing
		$meta_query[] = $forum_ids;

		// Set the meta_query var
		$posts_query->set( 'meta_query', $meta_query );
	}
}