sshpeer: make pipe polling code more explicit "hasbuffer" is a property on our special bufferedinputpipe class. When reading this code, I thought it might have had something special to do properties on built-in types. But "hasbuffer" doesn't appear in the CPython code base for either 2.7 or 3.7, so the answer is no. Let's make the code more explicit about the fact that it deals with our special bufferedinputpipe type. Differential Revision: https://phab.mercurial-scm.org/D2382

#require execbit

  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ chmod 644 foo
  $ hg ci -qAm '644'

  $ chmod 755 foo
  $ hg ci -qAm '755'

reverting to rev 0

  $ hg revert -a -r 0
  reverting foo
  $ hg st
  M foo
  $ hg diff --git
  diff --git a/foo b/foo
  old mode 100755
  new mode 100644

  $ cd ..