D4642: localrepo: iteratively derive local repository type

[indygreg (Gregory Szorc)]

indygreg added a comment.


  In https://phab.mercurial-scm.org/D4642#71269, @yuja wrote:
  
  > > +    Extensions should wrap these factory functions to customize repository type
  > >  +    creation. Note that an extension's wrapped function may be called even if
  > >  +    that extension is not loaded for the repo being constructed. Extensions
  > >  +    should check if their ``__name__`` appears in the
  > >  +    ``extensionmodulenames`` set passed to the factory function and no-op if
  > >  +    not.
  >
  > I assume this will be revisited later. I think it's a source of bugs to
  >  relying on extensions to check if they are enabled. It's also cumbersome
  >  to wrap a function referenced from another table.
  
  
  I agree it is not great and I hope to revisit this problem.
  
  FWIW we have similar problems with `extensions.wrapfunction()`. Many function wrappings bury their head in the sand with regards to universal function wrapping in multi-repo contexts. e.g. in hgweb, repo A can load an extension which wraps a function. Repo B doesn't want that extension loaded but the process still has the function wrapped. I'm not sure how to best handle this :/

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D4642

To: indygreg, #hg-reviewers
Cc: yuja, mercurial-devel