tests/test-mq-qsave.t

mq: avoid a silly conversion from binary nodeid to hex

We generally deal with binary nodeids in code. In this case the hex
nodeid was passed to strip.checksubstate() where it was passed to
repo.__getitem__, which of course accepts a binary nodeid.

Differential Revision: https://phab.mercurial-scm.org/D3141

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init

  $ echo 'base' > base
  $ hg ci -Ambase
  adding base

  $ hg qnew -mmqbase mqbase

  $ hg qsave
  $ hg qrestore 2
  restoring status: hg patches saved state