maybe_redirects_to_previous_thread_message()

function maybe_redirects_to_previous_thread_message() {
	$recipient = bp_get_messages_username_value();
	$user_id   = bp_core_get_userid( $recipient );

	if ( ! $thread_id = BP_Messages_Message::get_existing_thread( [$user_id], bp_loggedin_user_id() ) ) {
		return;
	}

	$thread_url = esc_url( bp_core_get_user_domain( bp_loggedin_user_id() ) . bp_get_messages_slug() . '/view/' . $thread_id . '/' );

	wp_redirect($thread_url);
	exit();
}