test: properly gate a zstd section This part of the test can't run if zstd is not available. This was caught by --pure test (who don't support zstd).

test: update test for expected test output In 1fac9b931d46 as new test session was introduced. It did not take in account some part that only ran for pure. The test is now fixed.

log: flag topo-sorted set as such This isn't required right now, but revs.istopo() should return True.

copies: fix duplicatecopies() with overlay context The reasoning for this check is in 78d760aa3607 (duplicatecopies: do not mark items not in the dirstate as copies, 2013-03-28). The check was then moved to workingfilectx in 754b5117622f (context: add workingfilectx.markcopied, 2017-10-15) and no corresponding check was added later when overlayworkingfilectx was added. Rather than adding the check there, this patch adds a more generic check on the callers side and removes the check in workingfilectx.markcopied(). Differential Revision: https://phab.mercurial-scm.org/D6380

tests: demonstrate crash when rebasing across copy with --collapse As reported by timeless. Differential Revision: https://phab.mercurial-scm.org/D6379

exthelper: add some semi-useful trace logs It'd be nice to make the trace functions a little better-named in the output, but I'm not sure how much better we can do without overhead. This at least lets you see if a single reposetup function is eating all the time or if it's spread over all of them. I needed this because Google's uber-extension has a long load time and I wasn't sure where the problem was. Differential Revision: https://phab.mercurial-scm.org/D6381

help: add missing blank line, making "revlog-compression" show up Differential Revision: https://phab.mercurial-scm.org/D6386