D1285: repoview: add a new attribute _visibilityexceptions and related API

[yuja (Yuya Nishihara)]

yuja added a comment.


  > I have spend a lot of time on this and I am unable to make this work without making it class attribute because to calculate filterrevs,  unfilteredrepo is passed and I lose the reference to the object on which I initially stored the visibilityexceptions. If I call `repo.filtered(filtername)`, I am getting a new object with empty visibilityexception set.
  
  How long should the visibilityexception be preserved?
  
  The safest one is to bind it to a temporary filteredrepo object, so that new `.filtered()`
  object won't see it.
  
  We could attach it to `unfi`, but in which case, we have to be careful to not leak
  the current visibilityexception to the subsequent sessions. A `repo` object may
  live longer than a single command/request session in hgweb or command server.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D1285

To: pulkit, #hg-reviewers, quark, yuja
Cc: yuja, lothiraldan, quark, mercurial-devel