merge: modify the logical statement Differential Revision: https://phab.mercurial-scm.org/D5476

exthelper: correct a documentation typo

lfs: convert to using exthelper to wrap functions I'm not 100% sure that upgraderequirements() can be double annotated safely, but it seems OK based on printing the address of the function being wrapped. One thing I've noticed is that @eh.reposetup doesn't do the usual check to ensure that it's a local repo. Should that be baked into @eh.reposetup() somehow, possibly with a non-default option to skip the check? It seems like a gaping hole if every function that gets registered needs to add this check.

tests: convert a test extension to use exthelper This provides test coverage to uipopulate().

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.