tests/test-rename-rev.t

discovery: fix docstring of `outgoing` class

Also, introduce a more correct name `ancestorsof` for what was named
`missingheads` before. For now, we just forward `ancestorsof` to `missingheads`
until all users are changed.

There were some mistakes in the old docstring / name:

* `missingheads` (new name: `ancestorsof`) contains the revs whose ancestors
  are included in the outgoing operation. It may contain non-head revs and revs
  which are already on the remote, so the name "missingheads" is wrong in two
  ways.
* `missing` contains only ancestors of `missingheads`, so not *all nodes*
  present in local but not in remote.
* `common` might not contain all common revs, e.g. not some that are not an
  ancestor of `missingheads`.

It seems like the misleading name have fostered an actual bug (issue6372),
where `outgoing.missingheads` was used assuming that it contains the heads of
the missing changesets.

  $ hg init
  $ mkdir d1 d1/d11 d2
  $ echo d1/a > d1/a
  $ echo d1/ba > d1/ba
  $ echo d1/a1 > d1/d11/a1
  $ echo d1/b > d1/b
  $ echo d2/b > d2/b
  $ hg add d1/a d1/b d1/ba d1/d11/a1 d2/b
  $ hg commit -m "intial"


Test single file

# One recorded copy, one copy to record after commit
  $ hg cp d1/b d1/c
  $ cp d1/b d1/d
  $ hg add d1/d
  $ hg ci -m 'copy d1/b to d1/c and d1/d'
  $ hg st -C --change .
  A d1/c
    d1/b
  A d1/d
# Errors out without --after for now
  $ hg cp --at-rev . d1/b d1/d
  abort: --at-rev requires --after
  [255]
# Errors out with non-existent source
  $ hg cp -A --at-rev . d1/non-existent d1/d
  d1/non-existent: no such file in rev 55d1fd85ef0a
  abort: no files to copy
  [255]
# Errors out with non-existent destination
  $ hg cp -A --at-rev . d1/b d1/non-existent
  abort: d1/non-existent: copy destination does not exist in 8a9d70fa20c9
  [255]
# Successful invocation
  $ hg cp -A --at-rev . d1/b d1/d
  saved backup bundle to $TESTTMP/.hg/strip-backup/8a9d70fa20c9-973ae357-copy.hg
# New copy is recorded, and previously recorded copy is also still there
  $ hg st -C --change .
  A d1/c
    d1/b
  A d1/d
    d1/b

Test moved file (not copied)

  $ hg co 0
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ mv d1/b d1/d
  $ hg rm -A d1/b
  $ hg add d1/d
  $ hg ci -m 'move d1/b to d1/d'
  created new head
  $ hg cp -A --at-rev . d1/b d1/d
  saved backup bundle to $TESTTMP/.hg/strip-backup/519850c3ea27-153c8fbb-copy.hg
  $ hg st -C --change .
  A d1/d
    d1/b
  R d1/b

Test using directory as destination

  $ hg co 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ cp -R d1 d3
  $ hg add d3
  adding d3/a
  adding d3/b
  adding d3/ba
  adding d3/d11/a1
  $ hg ci -m 'copy d1/ to d3/'
  created new head
  $ hg cp -A --at-rev . d1 d3
  abort: d3: --at-rev does not support a directory as destination
  [255]