obslog: extract display of a markers to its own function

tests: allow an empty merge commit to have tests pass without too many changes Not the greatest fix, but this allows us to have the same test case for all versions of Mercurial. Hash of 29 changes because instead of both parents only one is set in hg 5.3.

uncommit: use repo.setparents() instead of repo.dirstate.setparents() setparents() was added to localrepository class in 2012, and now we finally have some differences between calling repo.setparents() vs repo.dirstate.setparents(): _quick_access_* things, introduced in hg 5.3. This patch fixes potential quick-access desync problems where repo[b'.'] would be different from repo.dirstate.p1().

touch: use repo.setparents() instead of repo.dirstate.setparents() setparents() was added to localrepository class in 2012, and now we finally have some differences between calling repo.setparents() vs repo.dirstate.setparents(): _quick_access_* things, introduced in hg 5.3. This patch fixes potential quick-access desync problems where repo[b'.'] would be different from repo.dirstate.p1().

evolve: use repo.setparents() instead of repo.dirstate.setparents() setparents() was added to localrepository class in 2012, and now we finally have some differences between calling repo.setparents() vs repo.dirstate.setparents(): _quick_access_* things, introduced in hg 5.3. This patch fixes an actual quick-access desync problem where repo[b'.'] would be different from repo.dirstate.p1(), as demonstrated by test-evolve-phase-divergence.t when ran on hg 5.3rc0 and later. Modified _uncommitdirstate() too, because it is used in dirstatedance(), which sometimes follows repo.setparents() calls.

tests: demonstrate that evolve swaps parents of merge commits Tests currently pass, don't forget to change FIXME items.

ci: cache pytype-related files between runs