tests: demonstrate that copy info in changeset gets lost on amend When copy information is stored in changesets, it gets lost on amend. We didn't notice that until now because our users at Google have the config set to `compatibility`, which means copy information is stored in both changeset and filelogs. Differential Revision: https://phab.mercurial-scm.org/D12386

[build-system]
requires = ["setuptools", "wheel"]

[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true