tests/fakemergerecord.py

branchmap: Add a test about writing branchmap and aborted transaction

It turn out that we update the branchmap on disk whenever we recompute it…
including in a middle of a transaction. This means writing the new branchmap too
early (the changeset are not visible yet) and worse… it mean writing branchmap
for transaction we rollback.

so we introduce a test to highlight the issue (and prevent it to regress in the
future).

Differential Revision: https://phab.mercurial-scm.org/D12126

# Extension to write out fake unsupported records into the merge state
#
#

from __future__ import absolute_import

from mercurial import (
    mergestate as mergestatemod,
    registrar,
)

cmdtable = {}
command = registrar.command(cmdtable)


@command(
    b'fakemergerecord',
    [
        (b'X', b'mandatory', None, b'add a fake mandatory record'),
        (b'x', b'advisory', None, b'add a fake advisory record'),
    ],
    '',
)
def fakemergerecord(ui, repo, *pats, **opts):
    with repo.wlock():
        ms = mergestatemod.mergestate.read(repo)
        records = ms._makerecords()
        if opts.get('mandatory'):
            records.append((b'X', b'mandatory record'))
        if opts.get('advisory'):
            records.append((b'x', b'advisory record'))
        ms._writerecords(records)