tests/test-debugindexdot.out

make test-mq-qdelete work reliably (issue1180)

if after a and b has been applied, their hash starts with c, then the test
would fail (because there would be a rev c which would be seen as "applied")
so probability of failure would be 2*1/16.

created new head
digraph G {
	-1 -> 0
	0 -> 1
	0 -> 2
	2 -> 3
	1 -> 3
}