tests/test-mq-qsave.t

revset: speedup matching() by stopping the match early if a field does not match

Rather than getting all the fields that are being matches from every revision
and then comparing them to those of the target revision, compare each field one
by one and stop the match as soon as there is a match failure.

This can greatly reduce the match time when matching multiple fields.
The impact on match time when matching a single field seems negligible
(according to my measurements).

  $ 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