WITH MY_B_VPRINTF()
Issue         : In LP 64 machine max long value can be 20 digit
                decimal value. But in my_b_vprintf() the intermediate
                buffer storage used is 17 bytes length. This will lead to
                buffer overflow.
Solution      : Increased the buffer storage from 17 to 32 bytes.
                code is backported from 5.6


mysys/mf_iocache2.c:
  In function my_b_vprintf increased the size of local buff from 17 to
  32 bytes.