tests/test-histedit-revspec.t

scmutil: split platform-specific bits into their own modules

This parallels what's done for the util module, which imports either
mercurial.posix or mercurial.windows as 'platform' and then slurps the
appropriate functions into its own namespace.

This test requires parentrevspec support in revsets, so check for that
and skip the test if we're on an unusual hg that supports .t tests but
not parentrevspec.
  $ python -c 'from mercurial import revset ; revset.methods["parentpost"]' || exit 80

Enable extensions used by this test.
  $ cat >>$HGRCPATH <<EOF
  > [extensions]
  > graphlog=
  > histedit=
  > EOF

Repo setup.
  $ hg init foo
  $ cd foo
  $ echo alpha >> alpha
  $ hg addr
  adding alpha
  $ hg ci -m one
  $ echo alpha >> alpha
  $ hg ci -m two
  $ echo alpha >> alpha
  $ hg ci -m three
  $ echo alpha >> alpha
  $ hg ci -m four
  $ echo alpha >> alpha
  $ hg ci -m five

  $ hg log --style compact --graph
  @  4[tip]   08d98a8350f3   1970-01-01 00:00 +0000   test
  |    five
  |
  o  3   c8e68270e35a   1970-01-01 00:00 +0000   test
  |    four
  |
  o  2   eb57da33312f   1970-01-01 00:00 +0000   test
  |    three
  |
  o  1   579e40513370   1970-01-01 00:00 +0000   test
  |    two
  |
  o  0   6058cbb6cfd7   1970-01-01 00:00 +0000   test
       one
  

Run a dummy edit to make sure we get tip^^ correctly via revsingle.
  $ HGEDITOR=cat hg histedit "tip^^"
  pick eb57da33312f 2 three
  pick c8e68270e35a 3 four
  pick 08d98a8350f3 4 five
  
  # Edit history between eb57da33312f and 08d98a8350f3
  #
  # Commands:
  #  p, pick = use commit
  #  e, edit = use commit, but stop for amending
  #  f, fold = use commit, but fold into previous commit (combines N and N-1)
  #  d, drop = remove commit from history
  #  m, mess = edit message without changing commit content
  #
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

Run on a revision not ancestors of the current working directory.

  $ hg up 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg histedit -r 4
  abort: 08d98a8350f3 is not an ancestor of working directory
  [255]