tests/test-abort-checkin.t

context: override _dirstatestatus in workingcommitctx for correct matching

Before this patch, the result of "status()" on "workingcommitctx" may
incorrectly contain files other than ones to be committed, because
"workingctx._dirstatestatus()" returns the result of
"dirstate.status()" directly.

For correct matching, this patch overrides "_dirstatestatus" in
"workingcommitctx" and makes it return matched files only in
"self._status".

This patch uses empty list for "deleted", "unknown" and "ignored" of
status, because status between "changectx"s also makes them empty.

  $ cat > abortcommit.py <<EOF
  > from mercurial import util
  > def hook(**args):
  >     raise util.Abort("no commits allowed")
  > def reposetup(ui, repo):
  >     repo.ui.setconfig("hooks", "pretxncommit.nocommits", hook)
  > EOF
  $ abspath=`pwd`/abortcommit.py

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > mq =
  > abortcommit = $abspath
  > EOF

  $ hg init foo
  $ cd foo
  $ echo foo > foo
  $ hg add foo

mq may keep a reference to the repository so __del__ will not be
called and .hg/journal.dirstate will not be deleted:

  $ hg ci -m foo
  error: pretxncommit.nocommits hook failed: no commits allowed
  transaction abort!
  rollback completed
  abort: no commits allowed
  [255]
  $ hg ci -m foo
  error: pretxncommit.nocommits hook failed: no commits allowed
  transaction abort!
  rollback completed
  abort: no commits allowed
  [255]

  $ cd ..