tests/test-1102.t

subrepo: pull revisions on demand when archiving hg subrepos

Before, running 'hg archive -S' could result in

 abort: unknown revision '65903cebad86f1a84bd4f1134f62fa7dcb7a1c98'!

if a subrepo was missing completely or had missing changesets. Now,
the missing changesets will be pulled or cloned as appropriate.

This make Mercurial subrepos match Git subrepos which already took
care to fetch any missing commits before starting the archive.

  $ rm -rf a
  $ hg init a
  $ cd a
  $ echo a > a
  $ hg ci -Am0
  adding a
  $ hg tag t1 # 1
  $ hg tag --remove t1 # 2

  $ hg co 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg tag -f -r0 t1
  $ hg tags
  tip                                3:a49829c4fc11
  t1                                 0:f7b1eb17ad24