index: embed nodetree in index object to avoid reference cycle
Since the index has a reference to a nodetree and the nodetree has a
reference back to the index, there is a reference cycle, so the index
(and its nodetree) can never be freed. This patch fixes that by making
"nodetree" a plan C struct that the index can embed, and also
introduces a new "nodetreeObject" that is a Python type wrapping the
nodetree struct.
Thanks to Yuya for noticing this and for suggesting the solution.
All tests passed on the first attempt once it compiled (I guess C is
like Haskell in this regard?).
Differential Revision: https://phab.mercurial-scm.org/D4372
#require bzr
$ . "$TESTDIR/bzr-definitions"
$ cat > ghostcreator.py <<EOF
> import sys
> from bzrlib import workingtree
> wt = workingtree.WorkingTree.open('.')
>
> message, ghostrev = sys.argv[1:]
> wt.set_parent_ids(wt.get_parent_ids() + [ghostrev])
> wt.commit(message)
> EOF
ghost revisions
$ mkdir test-ghost-revisions
$ cd test-ghost-revisions
$ bzr init -q source
$ cd source
$ echo content > somefile
$ bzr add -q somefile
$ bzr commit -q -m 'Initial layout setup'
$ echo morecontent >> somefile
$ $PYTHON ../../ghostcreator.py 'Commit with ghost revision' ghostrev
$ cd ..
$ hg convert source source-hg
initializing destination source-hg repository
scanning source...
sorting...
converting...
1 Initial layout setup
0 Commit with ghost revision
$ glog -R source-hg
o 1@source "Commit with ghost revision" files+: [], files-: [], files: [somefile]
|
o 0@source "Initial layout setup" files+: [somefile], files-: [], files: []
$ cd ..