- each INSERT IGNORE generate 10000 duplicate key warnings each. By
   default only the first 64 warnings are saved on the  warning stack
  (and thus printed to the .result file). Since the order of the
  inserts are slightly random the first 64 warnings are also random.
  Fix by setting the number of saved warnigns to zero, since the test
  are only interested in checking that no records are allowed to be
  inserted by looking at "affected_rows"