tests/test-merge-subrepos.t

win32: assign winstdout to sys.__stdout__ as well (issue2888)

On Windows sys.stdout was being replaced with winstdout, which caused
util.system() to redirect its output (due to 406b6d7bdcb9). That causes
interactive tools (such as vim) to stop working.

  $ hg init

  $ echo a > a
  $ hg ci -qAm 'add a'

  $ hg init subrepo
  $ echo 'subrepo = http://example.net/libfoo' > .hgsub
  $ hg ci -qAm 'added subrepo'

  $ hg up -qC 0
  $ echo ax > a
  $ hg ci -m 'changed a'
  created new head

  $ hg up -qC 1
  $ cd subrepo
  $ echo b > b
  $ hg add b
  $ cd ..

Should fail, since there are added files to subrepo:

  $ hg merge
  abort: outstanding uncommitted changes in subrepository 'subrepo'
  [255]