exthelper: drop fileset/revset/template support for now Yuya raised concerns about duplicating registrar functionality. There are a couple of ideas to work around this, which would allow bringing them back, and then backporting to evolve. For now, I just want to get the subsequent changes landed before the bulk b'' rewrite makes rebasing too hard.

exthelper: simplify configitem registration

extensions: import the exthelper class from evolve 980565468003 (API) This should help make extensions that wrap a lot of stuff more comprehendible. It was copied unmodified, except: - fix up the imports - rename final_xxxsetup() -> finalxxxsetup() to appease checkcode - avoid a [] default arg to wrapcommand() .. api:: Add `exthelper` class to simplify extension writing by allowing functions, commands, and configitems to be registered via annotations. The previous APIs are still available for use.

narrow: detect if narrowspec was changed in a different share With this commit, `hg share` should be usable with narrow repos. Design explained on https://www.mercurial-scm.org/wiki/NarrowSharePlan I was running into cache invalidation problems when updating the narrowspec. After spending a day trying to figure out a good solution, I resorted to just assigning repo.narrowpats and repo._narrowmatch after invalidating them. Differential Revision: https://phab.mercurial-scm.org/D5278

tests: add test for narrow+share For how narrow+share is supposed to work, see https://www.mercurial-scm.org/wiki/NarrowSharePlan. Differential Revision: https://phab.mercurial-scm.org/D5276

narrow: keep narrowspec backup in store As suggested by Yuya in review of D4099. Differential Revision: https://phab.mercurial-scm.org/D5470

tests: update narrowspec when narrowspec, not dirstate, is accessed test-narrow-expanddirstate.t mimics a Google-internal extension that updates the narrowspec whenever the dirstate is accessed. Since 1d09ba0d2ed3 (narrow: move remaining narrow-limited dirstate walks to core, 2018-10-01) and a few commits before it, we no longer restrict repo.dirstate.walk() to the narrowspec. It is instead done at a higher level (e.g. context.status()). We were running into problems with the Google-internal extension when importing those commits. The issue was that the narrowspec was read before the first dirstate access. I believe the right fix is to instead update the narrowspec when trying to read it (not when reading the dirstate), so that's what this patch does. Differential Revision: https://phab.mercurial-scm.org/D5275

merge: extract helper for creating empty "actions" dict Replicating the set of actions in multiple places is bad. Differential Revision: https://phab.mercurial-scm.org/D5472

manifest: accept narrowmatch into constructor instead of getting from repo The manifest should ideally not know at all about the repo, so this is just a little step towards cleaning that up. Differential Revision: https://phab.mercurial-scm.org/D5469

py3: byteify one more sys.argv in gendoc.py