test_must_fail git rev-list --bisect --first-parent HEAD
'
+test_expect_success '--header shows a NUL after each commit' '
+ # We know that there is no Q in the true payload; names and
+ # addresses of the authors and the committers do not have
+ # any, and object names or header names do not, either.
+ git rev-list --header --max-count=2 HEAD |
+ nul_to_q |
+ grep "^Q" >actual &&
+ cat >expect <<-EOF &&
+ Q$(git rev-parse HEAD~1)
+ Q
+ EOF
+ test_cmp expect actual
+'
+
test_done