Fixing wrong memory read problem detected by Valgrind in "xml" test. The source of the problem was in my_vsnprintf() implementation.
Fixing wrong memory read problem detected by Valgrind in "xml" test.
The source of the problem was in my_vsnprintf() implementation.


strings/my_vsnprintf.c:
  Fixing a problem in vsnprintf('%.*s', len, ptr)
  When processing the above format, it's incorrect
  to use strlen() because the string is not necessarily
  a null terminated string.
  Changing strlen() followed by set_if_smaller()
  to strnlen() - which covers both cases - limiting
  by '\0' and by "len".

davidl-zend/zenddbi,natsys/mariadb_10.2,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2,ollie314/server,davidl-zend/zenddbi,davidl-zend/zenddbi,flynn1973/mariadb-aix,flynn1973/mariadb-aix,flynn1973/mariadb-aix,ollie314/server,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,ollie314/server,ollie314/server,ollie314/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix,slanterns/server,flynn1973/mariadb-aix,ollie314/server,davidl-zend/zenddbi,ollie314/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,davidl-zend/zenddbi,davidl-zend/zenddbi,natsys/mariadb_10.2,natsys/mariadb_10.2,ollie314/server,natsys/mariadb_10.2,natsys/mariadb_10.2