Merge branch 'jk/grep-binary-workaround-in-test' into maint

Recent versions of GNU grep are pickier when their input contains
arbitrary binary data, which some of our tests uses.  Rewrite the
tests to sidestep the problem.

* jk/grep-binary-workaround-in-test:
  t9200: avoid grep on non-ASCII data
  t8005: avoid grep on non-ASCII data