tests/test-empty-dir.t

narrow: move checking for narrow requirement into _narrowmatch()

We want to move narrowmatch() and others into core, so we need to get
rid of the dependence on the "narrow_opts" from the closure in
narrowrepo.wraprepo(). We can simply check if the narrow requirement
is set. I think that seems like an improvement regardless of moving
narrowmatch().

Differential Revision: https://phab.mercurial-scm.org/D2489

  $ hg init

  $ echo 123 > a
  $ hg add a
  $ hg commit -m "first" a

  $ mkdir sub
  $ echo 321 > sub/b
  $ hg add sub/b
  $ hg commit -m "second" sub/b

  $ cat sub/b
  321

  $ hg co 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ cat sub/b 2>/dev/null || echo "sub/b not present"
  sub/b not present

  $ test -d sub || echo "sub not present"
  sub not present