copies: consider nullrev a common ancestor
I've seen many bugs in the git codebase that were caused by it not
having a null revision and being forced to treat root commits
differently. Mercurial has a null revision and I think it's generally
a bug to treat it differently from other commits in graph algorithms.
This effectively undoes
83cfa1baf8ad (copies: don't report copies with
unrelated branch, 2010-01-01). The test cases that that commit added
still passes. I suspect some other fix after that commit made it
unnecessary.
Differential Revision: https://phab.mercurial-scm.org/D5594
# Balto (https://bitbucket.org/lothiraldan/balto/src) is a test orchestrator
# which is compatible with all test runner that can emit the LITF
# (https://github.com/lothiraldan/litf) test format.
# The plugin for the Mercurial test runner is mercurial-litf
# (https://pypi.org/project/mercurial-litf/). Make sure to follow the
# instruction and configuration instructions here:
# https://bitbucket.org/lothiraldan/mercurial_litf/src/default/
# You can launch Balto with `balto /path/to/mercurial/tests/`
name = "Mercurial Test Suite"
tool = "mercurial"