Fixed memory overrun when doing REPAIR on table with multi-part auto_increment key where one part was a packed CHAR


myisam/mi_check.c:
  Fixed memory overrun in _mi_put_key_in_record
myisam/mi_key.c:
  Fixed unnecessary memory allocation
mysql-test/r/insert_select.result:
  Added test case for memory corruption
mysql-test/t/insert_select.test:
  Added test case for memory corruption
mysys/safemalloc.c:
  Removed compiler warnings
sql/sql_acl.cc:
  Fixed core dump when running with --debug