backout: backed out changeset 5d83a40cd3f8 This is the re-send of the backout in D11757 that I accidentally queued. I'll rewrite the original commit message: ...sigh We do not have Python 3 packaging for thg on Windows where the vast majority of of users use the thg installer for Mercurial. Until this is done (hopefully this cycle), we're keeping Python. (end of the old commit message) On top of this, we have a solid lead to have competent people take care of this packaging issue for us in time for the 6.1 release, which is really the main reason for us to wait. We're trying our best to make this work, so please bear with us. Differential Revision: https://phab.mercurial-scm.org/D11770

status: keep second-ambiguous mtimes during fixup Now that we support the feature, we can keep "second ambiguous" mtime during the fixup phase. These are the mtime that would be ambiguous if we did not had sub-second précions. See the v2 format documentation for details. Differential Revision: https://phab.mercurial-scm.org/D11847

dirstate-item: make sure we load `mtime-second-ambiguous` from disk Now that we support the associated logic, we can safely load it from it. It is no longer necessary to ignore the stored mtime when the flag is encountered. Differential Revision: https://phab.mercurial-scm.org/D11846

dirstate-item: make sure we set the mtime-second-ambiguous on v2 write We want to preserve the second-ambiguity alongside the ambiguous mtime. So we use the decimated flag for that. note: the C code was already doing so. No change was needed to it. Differential Revision: https://phab.mercurial-scm.org/D11845

dirstate-item: ignore mtime to write v1 when `mtime-second-ambiguous` is set We cannot preserve that information in the v1 format so that mtime is ambiguous. Differential Revision: https://phab.mercurial-scm.org/D11844

dirstate-item: implement the comparison logic for mtime-second-ambiguous If the flag is set we now process it properly. We "just" need to actually set it and persist it. Differential Revision: https://phab.mercurial-scm.org/D11843

dirstate-item: add a "second_ambiguous` flag in the mtime tuple This will be used to support the `mtime-second-ambiguous` flag from dirstate v2. See format documentation for details. For now, we only make it possible to store the information, no other logic have been added. Differential Revision: https://phab.mercurial-scm.org/D11842

dirstate: drop comparison primitive on the timestamp class All comparison are now managed without using operator : - the status mtime comparisons is handled by the DirstateItem, - the fixup reliability check, - the update "hack". So we no longer needs the operator and should discourage its usage. Differential Revision: https://phab.mercurial-scm.org/D11841

largefile: use the proper "mtime boundary" logic during fixup This will prevent ambiguous cache entry to be used in racy situation. This fix flakiness in test and some real live misbehavior. Differential Revision: https://phab.mercurial-scm.org/D11800

status: move the boundary comparison logic within the timestamp module Some extensions will need it too. So lets isolate the logic. It also makes things clearer. Differential Revision: https://phab.mercurial-scm.org/D11799