Code Changes

		return isset($this->config['allow_avatar_gravatar']);

		// Get current avatar type of guest user
		$sql = 'SELECT user_avatar_type
			FROM ' . $this->table_prefix . 'users
			WHERE user_id = ' . ANONYMOUS;
		$result = $this->db->sql_query($sql);
		$backup_type = $this->db->sql_fetchfield('user_avatar_type');
		$this->db->sql_freeresult($result);

		// Try to set avatar type to string
		$sql = 'UPDATE ' . $this->table_prefix . "users
			SET user_avatar_type = 'avatar.driver.upload'
			WHERE user_id = " . ANONYMOUS;
		$this->db->sql_return_on_error(true);
		$effectively_installed = $this->db->sql_query($sql);
		$this->db->sql_return_on_error();

		// Restore avatar type of guest user to previous state
		$sql = 'UPDATE ' . $this->table_prefix . "users
			SET user_avatar_type = '{$backup_type}'
			WHERE user_id = " . ANONYMOUS;
		$this->db->sql_query($sql);

		return $effectively_installed !== false;