tests/test-lock-badness.t

performance: speedup computation of hidden revisions

In their current state, revset calls can be very costlys, as we
test predicates on the entire repository. The hidden filter is very
widely used, and needs to be very fast.

This change drops revset calls in favor of direct revision manipulation.

Performance test on my Mercurial checkout

- 19857 total changesets,
- 1584 obsolete changesets,
- 13310 obsolescence markers.

Before:
 ! hidden
 ! wall 0.077553

After this changes:
  ! hidden
  ! wall 0.011230

Performance test on a Mozilla central checkout:

- 117293 total changesets,
- 1 obsolete changeset,
- 1 obsolescence marker.

Before:
  ! hidden
  ! wall 0.389472

After:
  ! hidden
  ! wall 0.000079

  $ "$TESTDIR/hghave" unix-permissions || exit 80

  $ hg init a
  $ echo a > a/a
  $ hg -R a ci -A -m a
  adding a

  $ hg clone a b
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo b > b/b
  $ hg -R b ci -A -m b
  adding b

  $ chmod 100 a/.hg/store

  $ hg -R b push a
  pushing to a
  abort: could not lock repository a: Permission denied
  [255]

  $ chmod 700 a/.hg/store