Steps to reproduce the issue

Update a multilingual Joomla <= 3.4.0 to a 3.4.1-rc on a system with msql database.

Expected result

The update succeeds. In post-install messages a new message with title COM_CPANEL_MSG_LANGUAGEACCESS340_TITLE should be shown.

Actual result

An SQL error is shown as follows for the insert statement for this new post-install message, the syntax error I have marked with bold italics:

An error has occurred.

    1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'admin://components/com_admin/postinstall/languageaccess340.php', 'admin_postinst' at line 2 SQL=INSERT INTO `c6gp0_postinstall_messages` (`extension_id`, `title_key`, `description_key`, `action_key`, `language_extension`, `language_client_id`, `type`, `action_file`, `action`, `condition_file`, `condition_method`, `version_introduced`, `enabled`) VALUES (700, 'COM_CPANEL_MSG_LANGUAGEACCESS340_TITLE', 'COM_CPANEL_MSG_LANGUAGEACCESS340_BODY', '', 'com_cpanel', 1, 'message', ', '', 'admin://components/com_admin/postinstall/languageaccess340.php', 'admin_postinstall_languageaccess340_condition', '3.4.1', 1);

Note the unclosed single quote of the value for column action!

System information (as much as possible)

Database driver type is MySQLi, Joomla version see title.

Additional comments

Check of the SQL updates scripts 3.4.0-2015-02-26.sql has shown that the error was only in the one for MySQLi.