tests/test-narrow-copies.t

ancestors: actually iterate over ancestors in topological order (issue5979)

This code previously used a dequeue logic, the first ancestors seen were the
first ancestors to be emitted. In branching/merging situations, it can result
in ancestors being yielded before their descendants, breaking the object
contract.

We got affected by this issue while working on the copy tracing code. At about
the same time, Axel Hecht <[e-mail]> reported the issue and provided
the test case used in this changeset. Thanks Axel.

Running `hg perfancestors` does not show a significant difference between the
old and the new version.

  $ . "$TESTDIR/narrow-library.sh"

create full repo

  $ hg init master
  $ cd master

  $ mkdir inside
  $ echo inside > inside/f1
  $ mkdir outside
  $ echo outside > outside/f2
  $ hg ci -Aqm 'initial'

  $ hg mv outside/f2 inside/f2
  $ hg ci -qm 'move f2 from outside'

  $ echo modified > inside/f2
  $ hg ci -qm 'modify inside/f2'

  $ cd ..

  $ hg clone --narrow ssh://user@dummy/master narrow --include inside
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 2 files
  new changesets *:* (glob)
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrow

  $ hg co 'desc("move f2")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg status
  $ hg diff
  $ hg diff --change . --git
  diff --git a/inside/f2 b/inside/f2
  new file mode 100644
  --- /dev/null
  +++ b/inside/f2
  @@ -0,0 +1,1 @@
  +outside

  $ hg log --follow inside/f2 -r tip
  changeset:   2:bcfb756e0ca9
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify inside/f2
  
  changeset:   1:5a016133b2bb
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     move f2 from outside