D5516: fix: add some arguments to facilitate extensions

[hooper (Danny Hooper)]

hooper added a comment.


  In https://phab.mercurial-scm.org/D5516#81679, @durin42 wrote:
  
  > I'm -0 on this: what's special about this functionality that it needs to be an extension of an extension instead of something that can be done in core?
  
  
  Google's internal use of this extension makes some customizations that I doubt would be appealing in core. This patch makes some of it simpler to implement. Making all of it possible through configs/templates might be unduly complex.
  
  A better version of this might put "ctx" into the templater inside Fixer.command, and maybe add a no-op Fixer.cleanup method to make that part more explicit. I think that would be a less trivial super set of this patch.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D5516

To: hooper, #hg-reviewers
Cc: durin42, mercurial-devel