tests/fakemergerecord.py

rust-dirstate-v2: show `unused_bytes` counter is not reset on total rewrite

This was picked up by @aalekseyev when doing unrelated debugging.

The Rust implementation was never resetting this counter, so a brand new file
would carry over the old counter.

As I write this, my counter is a supposed 7389089 unused bytes for a total of
170978 bytes in the data file. Feel free to post your own high score.

Differential Revision: https://phab.mercurial-scm.org/D12593

# 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)