narrow: always wrap repo It's simpler to always wrap the repo. This prepares for moving narrowrepo.narrowmatch() onto localrepo by showing that it's now safe to always wrap the repo (and thus always define narrowmatch() etc.). Note that since narrowmatch() returns an always-matcher (rather than None) in non-narrow repos, this may mean a performance hit when the narrow extension is enabled because it adds a no-op filtering step in various places against the always-matcher. I'll restore some of that soon. Differential Revision: https://phab.mercurial-scm.org/D2491

narrow: consider both local and remote matchers in narrowchangegroup The existing code that picked one or the other seemed very suspicious. This patch makes us intersect the local matcher with the matcher from the remote, which seems better. It fixes one test case and makes another one that used to crash no longer crash, but instead silently succeed with a push that's lossy, so that remains to be fixed. The real reason for doing this now is that I'm going to move narrowrepo.narrowmatch() onto localrepo and then it will always be defined, which would otherwise break this code. Differential Revision: https://phab.mercurial-scm.org/D2490

narrow: move checking for narrow requirement into _narrowmatch() We want to move narrowmatch() and others into core, so we need to get rid of the dependence on the "narrow_opts" from the closure in narrowrepo.wraprepo(). We can simply check if the narrow requirement is set. I think that seems like an improvement regardless of moving narrowmatch(). Differential Revision: https://phab.mercurial-scm.org/D2489

narrow: move changegroup.supportedoutgoingversions() override to core Also document why we need cg3 or higher. Differential Revision: https://phab.mercurial-scm.org/D2488