tests/test-1102.t

bundle2.processbundle: let callers request default behavior

This patch series is intended to allow bundle2 push reply part handlers to
make changes to the local repository; it has been developed in parallel with
an extension that allows the server to rebase incoming changesets while applying
them.

The default transaction getter for processbundle is a private function that
raises an exception; this diff lets calling code pass None as the transaction
getter to explicitly request this default behavior.

The next diff will check a config option to determine whether to provide a
transaction to the reply bundle processor.  If one shouldn't be provided, the
code needs a way to specify that the default behavior should be used.

  $ 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

  $ cd ..