rebase: when collapsing, p1 == dest, so use the former only
`dest` is the destination we're rebasing onto, which is always the
same as `p1` when using `--collapse`. This lets us simplify a bit.
Differential Revision: https://phab.mercurial-scm.org/D9073
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true