$ HGENCODING=utf-8

  $ export HGENCODING

  $ try() {

  >   hg debugrevspec --debug $@

  > }

  $ log() {

  >   hg log --template '{rev}\n' -r "$1"

  > }

  $ hg init repo

  $ cd repo

  $ try 'p1()'

  (func

    ('symbol', 'p1')

    None)

  $ try 'p2()'

  (func

    ('symbol', 'p2')

    None)

  $ try 'parents()'

  (func

    ('symbol', 'parents')

    None)

null revision

  $ log 'p1()'

  $ log 'p2()'

  $ log 'parents()'

working dir with a single parent

  $ echo a > a

  $ hg ci -Aqm0

  $ log 'p1()'

  0

  $ log 'tag() and p1()'

  $ log 'p2()'

  $ log 'parents()'

  0

  $ log 'tag() and parents()'

merge in progress

  $ echo b > b

  $ hg ci -Aqm1

  $ hg up -q 0

  $ echo c > c

  $ hg ci -Aqm2

  $ hg merge -q

  $ log 'p1()'

  2

  $ log 'p2()'

  1

  $ log 'tag() and p2()'

  $ log 'parents()'

  1

  2