http://mercurial.selenic.com/bts/issue2137

Setup:

create a little extension that has 3 side-effects:

1) ensure changelog data is not inlined

2) make revlog to use lazyparser

3) test that repo.lookup() works

1 and 2 are preconditions for the bug; 3 is the bug.

  $ cat > commitwrapper.py <<EOF

  > from mercurial import extensions, node, revlog

  > 

  > def reposetup(ui, repo):

  >     def wrapcommit(orig, *args, **kwargs):

  >         result = orig(*args, **kwargs)

  >         tip1 = node.short(repo.changelog.tip())

  >         tip2 = node.short(repo.lookup(tip1))

  >         assert tip1 == tip2

  >         ui.write('new tip: %s\n' % tip1)

  >         return result

  > 

  >     extensions.wrapfunction(repo, 'commit', wrapcommit)

  > 

  > def extsetup(ui):

  >     revlog._maxinline = 8             # split out 00changelog.d early

  >     revlog._prereadsize = 8           # use revlog.lazyparser

  > EOF

  $ cat >> $HGRCPATH <<EOF

  > [extensions]

  > commitwrapper = `pwd`/commitwrapper.py

  > EOF

  $ hg init repo1

  $ cd repo1

  $ echo a > a

  $ hg commit -A -m'add a with a long commit message to make the changelog a bit bigger'

  adding a

  new tip: 553596fad57b

Test that new changesets are visible to repo.lookup():

  $ echo a >> a

  $ hg commit -m'one more commit to demonstrate the bug'

  new tip: 799ae3599e0e

  $ hg tip

  changeset:   1:799ae3599e0e

  tag:         tip

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     one more commit to demonstrate the bug