tests/test-update-issue1456.t

subrepo: use safehasattr instead of hasattr

Some of these instances could be rewritten as clever getattr(x, y,
default) ladders, but that felt like it impeded readability too much
to be worth the modest efficiency gain.

  $ rm -rf a
  $ hg init a
  $ cd a

  $ echo foo > foo
  $ hg ci -qAm0
  $ chmod +x foo
  $ hg ci -m1
  $ hg co -q 0
  $ echo dirty > foo
  $ hg up -c
  abort: uncommitted local changes
  [255]
  $ hg up -q
  $ cat foo
  dirty
  $ hg st -A
  M foo

Validate update of standalone execute bit change:

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ chmod -x foo
  $ hg ci -m removeexec
  nothing changed
  [1]
  $ hg up -C 0
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg up
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg st