upgraderepo: add a config option for parallel computation The option is put to use to compute new copy tracing side data in parallel. It use the multiprocessing module as it had the appropriate primitive for what we needed. Gregory Szorc had concerned on windows so we disabled it there. See inline comment for details on the parallel implementation.

upgrade-repo: colorize some of the output Having clear color for requirement added and removed is useful.

tests: remove hardcoded errno values Fixes test failures on hurd-i386 Ref: https://bugs.debian.org/946178 Differential Revision: https://phab.mercurial-scm.org/D7556

tests: expect return status 255 on exception for test-blackbox.t with chg Differential Revision: https://phab.mercurial-scm.org/D7554

tests: fix command name in test-blackbox.t to be bytes This command is only used when tests are run with --with-chg, so this was missed before. Differential Revision: https://phab.mercurial-scm.org/D7553

tests: fix deprecation warning about regex flags not at beginning of expr This may only show up when running the tests under python3.6+. Currently the only test that does this is test-patchbomb-tls.t, and it only uses (?i), so that's all that's handled at the moment. Differential Revision: https://phab.mercurial-scm.org/D7552

tests: fix test-chg.t to work with py3 (no setprocname) Differential Revision: https://phab.mercurial-scm.org/D7551

amend: check for file modifications when updating dirstate (issue6233) Previously, we called dirstate.normal(f), which would put information into the dirstate claiming that the file on disk is what it "should be" for the current checkout, and it would have the size and timestamp of the most recent modification to the file (which is not necessarily the one we just committed). If the file was modified while the commit message editor was open, we would put incorrect information into the dirstate. Differential Revision: https://phab.mercurial-scm.org/D7521

graft: never set both parents equal in the dirstate (issue6098) merge.graft() can set both parents equal in the dirstate when keepparent=True. We don't seem to set that in core, but the evolve extension does use it. So I couldn't figure out a way to add a test for this patch in core. Differential Revision: https://phab.mercurial-scm.org/D7549

graft: extract `repo['.']` to local variable It's used in two places and I'm about to use it more. Differential Revision: https://phab.mercurial-scm.org/D7548