tests/test-dirstate.t

setdiscovery: fix hang when #heads>200 (issue2971)

When setting up the next sample, we always add all of the heads, regardless
of the desired max sample size. But if the number of heads exceeds this
size, then we don't add any more nodes from the still undecided set.
(This is debatable per se, and I'll investigate it, but it's how we designed
it at the moment.)

The bug was that we always added the overall heads, not the heads of the
remaining undecided set. Thus, if #heads>200 (desired sample size), we
did not make progress any longer.

------ Test dirstate._dirs refcounting

  $ hg init t
  $ cd t
  $ mkdir -p a/b/c/d
  $ touch a/b/c/d/x
  $ touch a/b/c/d/y
  $ touch a/b/c/d/z
  $ hg ci -Am m
  adding a/b/c/d/x
  adding a/b/c/d/y
  adding a/b/c/d/z
  $ hg mv a z
  moving a/b/c/d/x to z/b/c/d/x
  moving a/b/c/d/y to z/b/c/d/y
  moving a/b/c/d/z to z/b/c/d/z
  $ cd ..

Issue1790: dirstate entry locked into unset if file mtime is set into
the future

Prepare test repo:

  $ hg init u
  $ cd u
  $ echo a > a
  $ hg add
  adding a
  $ hg ci -m1

Set mtime of a into the future:

  $ touch -t 202101011200 a

Status must not set a's entry to unset (issue1790):

  $ hg status
  $ hg debugstate
  n 644          2 2021-01-01 12:00:00 a
  $ cd ..