MYSQL_TEST_SKIP_CONNECT_FAILURE which controls how to deal with connection
problems. If MYSQL_TEST_SKIP_CONNECT_FAILURE = false (default) connection
problems will make a test fail. If you set MYSQL_TEST_SKIP_CONNECT_FAILURE
to any value that evaluates to true in PHP, a test which cannot connect to
the database will be skipped.
We added a flag to check if a MySQL column type is a binary type. If so,
ext/mysql should return data for such columns not as unicode strings but
as binary strings if unicode.semantics is on.