MySQL STRICT_TRANS_TABLES mode and truncated text values

I just upgraded Apache, PHP and MySQL to their current versions on my development system. After that a unit test of one of my PHP classes failed on inserting a row in a MySQL table. The test inserts text with a greater length than the maximum column length of a VARCHAR column.

This test fails because the new server runs with STRICT_TRANS_TABLES mode. It means that a inserted value must be equal to the stored value or the statement fails. Without the mode setting the inserted value is truncated to the column's maximum length.