revlog: add a callback "tracking" duplicate node addition
If a changegroup contains node already added to the repository, they will be
skipped. Skipping them is the right behavior (we don't need to store things
twice), but it can hide some information to the code doing the unbundle (eg:
shelve looking for the tip of the bundle).
The first step to improve this situation is to add a low level callback. We do
not need this tracking on all revlog, so actual tracking will be added in the
next changeset.
https://bz.mercurial-scm.org/2137
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):
> class wraprepo(repo.__class__):
> def commit(self, *args, **kwargs):
> result = super(wraprepo, self).commit(*args, **kwargs)
> tip1 = node.short(repo.changelog.tip())
> tip2 = node.short(repo.lookup(tip1))
> assert tip1 == tip2
> ui.write(b'new tip: %s\n' % tip1)
> return result
> repo.__class__ = wraprepo
>
> 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
$ cd ..