D1527: context: add an abstract base class for filectx

[phillco (Phil Cohen)]

phillco added a comment.


  > What exactly is that cycle? Can we break one of the links with a local import?
  
  It's the same filectx -> ctx -> fileset -> merge -> filemerge cycle that frustrated earlier. We can't circumvent it this time (I think) because the import is in the module, not a function.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D1527

To: phillco, #hg-reviewers, martinvonz
Cc: mercurial-devel