D3733: tests: suppress read(-1) -> '' calls in fileobjectobserver

[durin42 (Augie Fackler)]

durin42 added a subscriber: indygreg.
durin42 added a comment.


  @indygreg I'm not sure if this undermines your testing strategy at all, but if it does we can try and figure out another path forward...

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D3733

To: durin42, pulkit, #hg-reviewers
Cc: indygreg, mercurial-devel