$ echo '[extensions]' >> $HGRCPATH

  $ echo 'mq =' >> $HGRCPATH

  $ hg init repo

  $ cd repo

  $ echo foo > foo

  $ hg ci -qAm 'add a file'

  $ hg qinit

  $ hg qnew foo

  $ echo foo >> foo

  $ hg qrefresh -m 'append foo'

  $ hg qnew bar

  $ echo bar >> foo

  $ hg qrefresh -m 'append bar'

try to commit on top of a patch

  $ echo quux >> foo

  $ hg ci -m 'append quux'

  abort: cannot commit over an applied mq patch

  [255]

cheat a bit...

  $ mv .hg/patches .hg/patches2

  $ hg ci -m 'append quux'

  $ mv .hg/patches2 .hg/patches

qpop/qrefresh on the wrong revision

  $ hg qpop

  abort: popping would remove a revision not managed by this patch queue

  [255]

  $ hg qpop -n patches

  abort: popping would remove a revision not managed by this patch queue

  [255]

  $ hg qrefresh

  abort: working directory revision is not qtip

  [255]

  $ hg up -C qtip

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg qpop

  abort: popping would remove a revision not managed by this patch queue

  [255]

  $ hg qrefresh

  abort: cannot refresh a revision with children

  [255]

  $ hg tip --template '{rev} {desc}\n'

  3 append quux

qpush warning branchheads

  $ cd ..

  $ hg init branchy

  $ cd branchy

  $ echo q > q

  $ hg add q

  $ hg qnew -f qp

  $ hg qpop

  popping qp

  patch queue now empty

  $ echo a > a

  $ hg ci -Ama

  adding a

  $ hg up null

  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg branch b

  marked working directory as branch b

  $ echo c > c

  $ hg ci -Amc

  adding c

  $ hg merge default

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  (branch merge, don't forget to commit)

  $ hg ci -mmerge

  $ hg up default

  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg log

  changeset:   2:65309210bf4e

  branch:      b

  tag:         tip

  parent:      1:707adb4c8ae1

  parent:      0:cb9a9f314b8b

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     merge

  changeset:   1:707adb4c8ae1

  branch:      b

  parent:      -1:000000000000

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     c

  changeset:   0:cb9a9f314b8b

  user:        test

  date:        Thu Jan 01 00:00:00 1970 +0000

  summary:     a

  $ hg qpush

  applying qp

  now at: qp