upgrade: only process revlogs that needs it by default We have more and more requirement that does not affect revlog or that only affect some of them. It is silly to force a full processing of all revlog to juste move the requirement around, or to simply rewrite the dirstate. So now, only the revlog that needs to be touched will be touched. Unless the --changelog & al flags are used. Differential Revision: https://phab.mercurial-scm.org/D11871

upgrade: issue a message when a revlog type has to be upgraded This is more explicite and prepare for a smoother transition to smarter picking of the revlog we will process. Differential Revision: https://phab.mercurial-scm.org/D11870

upgrade: explicitly warn when a `--no-xxx` flag is overwritten Some format upgrade/downgrades -needs- revlog to be recomputed. So we now detect that individually and warn when it contradict explicitly passed flag. This is part of a larger series to make `debugupgraderepo` smarter about which revlog it picks by default. Differential Revision: https://phab.mercurial-scm.org/D11869

upgrade: make the list of explicitly specified revlog a dict This makes various logic simpler and will help making future patch clearer. Differential Revision: https://phab.mercurial-scm.org/D11868

upgrade: move the revlog selection code lower down the chain We about about to make revlog section smarter. Moving the code around will make the next changesets clearer. Differential Revision: https://phab.mercurial-scm.org/D11867

rhg: Set second_ambiguous as needed in post-status fixup This fixes an intermittent bug that manifested only in test-revert.t, and unfortunately not on CI. On a fast enough machine we could have: 1. A file is modified 2. `rhg status` writes an updated dirstate-v1 3. The same file is modified again … all within the same integer second. Because the dirstate-v1 file format does not store sub-second precision, step 2 must write the file’s mtime as "unknown" because of the possibility of step 3. However, most of the code now handles timestamps with nanosecond precision in order to take advantage of it in dirstate-v2. `second_ambiguous` must be set for timestamps that become ambiguous if sub-second precision is dropped (such as through serialization in dirstate-v1 format). Differential Revision: https://phab.mercurial-scm.org/D11889

dirstate: Document Timestamp.second_ambiguous Differential Revision: https://phab.mercurial-scm.org/D11888

hghave: fix the check for suid on platforms lacking support The mac tests were raising an AttributeError without the default arg. Differential Revision: https://phab.mercurial-scm.org/D11906

upgrade: byteify a few error messages These were flagged by pytype (which is currently disabled on this file due to another failure). Differential Revision: https://phab.mercurial-scm.org/D11905

rhg: support the new extension suboptions syntax See inline comments Differential Revision: https://phab.mercurial-scm.org/D11874

branching: merge stable into default

dirstate-v2: fix upgrade on an empty repository This used to crash as the dirstate file does not exist in this case. Differential Revision: https://phab.mercurial-scm.org/D11866