tests/test-backwards-remove.t

discovery: simplify branchmap construction against legacy server

All necessary data to fire a simple revset query are already known. No call to
ancestors are needed. Such ancestors calculation was already done to compute
outgoing.missing.

  $ hg init
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ ls
  a
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"
  $ hg co 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

B should disappear

  $ ls
  a