branchcache: add more test for the logic around obsolescence and branch heads
While working on branch-cache-v3, we noticed some ambiguity in the
filtered+obsolete hash. However this was only caught by a rebase test by
chance.
It seems important to explicitly tests these cases.
$ hg init repo
$ cd repo
$ touch unknown
$ touch a
$ hg add a
$ hg ci -m "1"
$ touch b
$ hg add b
$ hg ci -m "2"
Should show unknown
$ hg status
? unknown
$ hg revert -r 0 --all
removing b
Should show unknown and b removed
$ hg status
R b
? unknown
Should show a and unknown
$ ls -A
.hg
a
unknown