BUG#13556441: CHECK AND REPAIR TABLE SHOULD BE MORE ROBUST [4]
BUG#13556441: CHECK AND REPAIR TABLE SHOULD BE MORE ROBUST [4]

Problem description:
mysql server crashes when we run repair table on currupted table.

Analysis:
The problem with this bug seem to be key_reflength out of bounds
(186 according to debugger). We read this value from meta-data
segment of .MYI file while doing mi_open().

If you look into _mi_kpointer() you can see that the upper limit
for key_reflength is 7.

Solution:
In mi_open() there is a line like:
  if (share->base.keystart > 65535 || share->base.rec_reflength > 8)
we should verify key_reflength here as well.

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