D7512: exchange: guard against method invocation on `b2caps=None` args

[yuja (Yuya Nishihara)]

yuja added a comment.


  >   >>   """add a changegroup part to the requested bundle"""
  >   >>
  >   >> - if not kwargs.get('cg', True):
  >   >>
  >   >> +    if not kwargs.get('cg', True) or not b2caps:
  >   >>
  >   >>   return
  >   >
  >   > Is it valid to call these functions with `b2caps=None`? I suspect it would
  >   > be a bug or a data corruption.
  >   The only caller I can find[1] will indeed pass something, even if it is `{}`.  I can change these to asserts if you want.
  >   [1] https://www.mercurial-scm.org/repo/hg/file/tip/mercurial/exchange.py#l2448
  
  Well, I have no expertise around this module, so I have no idea which is
  better. I just don't know if it's valid to return successfully if b2caps
  is None.

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D7512/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D7512

To: mharbison72, #hg-reviewers, dlax, indygreg
Cc: yuja, mercurial-devel