tests/test-push-checkheads-pruned-B1.t

branchmap: pass changelog into branchmap functions

As part of building the branchmap, we loop over revs and call branchmap()
or _branchmap(). Previously, these functions were accessing repo.changelog.
We know from past experience that repo.changelog in loops is bad for
performance.

This commit teaches the branchmap code to pass a changelog instance into
branchmap() and _branchmap() so we don't need to pay this penalty.

On my MBP, this appears to show a speedup on a clone of the
mozilla-unified repo:

$ hg perfbranchmap --clear-revbranch
! base
! wall 21.078160 comb 21.070000 user 20.920000 sys 0.150000 (best of 3)
! wall 20.574682 comb 20.560000 user 20.400000 sys 0.160000 (best of 3)

$ hg perfbranchmap
! base
! wall 4.880413 comb 4.870000 user 4.860000 sys 0.010000 (best of 3)
! wall 4.573968 comb 4.560000 user 4.550000 sys 0.010000 (best of 3)

Differential Revision: https://phab.mercurial-scm.org/D5161

====================================
Testing head checking code: Case B-1
====================================

Mercurial checks for the introduction of new heads on push. Evolution comes
into play to detect if existing branches on the server are being replaced by
some of the new one we push.

This case is part of a series of tests checking this behavior.

Category B: simple case involving pruned changesets
TestCase 1: single pruned changeset

.. old-state:
..
.. * 1 changeset branch
..
.. new-state:
..
.. * old branch is pruned
.. * 1 new unrelated branch
..
.. expected-result:
..
.. * push allowed
..
.. graph-summary:
..
..       ◔ B
..       |
..   A ⊗ |
..     |/
..     ●

  $ . $TESTDIR/testlib/push-checkheads-util.sh

Test setup
----------

  $ mkdir B1
  $ cd B1
  $ setuprepos
  creating basic server and client repo
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd client
  $ hg up 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ mkcommit B0
  created new head
  $ hg debugobsolete --record-parents `getid "desc(A0)"`
  obsoleted 1 changesets
  $ hg log -G --hidden
  @  74ff5441d343 (draft): B0
  |
  | x  8aaa48160adc (draft): A0
  |/
  o  1e4be0697311 (public): root
  

Actual testing
--------------

  $ hg push
  pushing to $TESTTMP/B1/server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  1 new obsolescence markers
  obsoleted 1 changesets

  $ cd ../..