tests/test-update-reverse.t

checkheads: take future obsoleted heads into account

If we push some successors they will likely create a new head on
remote. However as the obsoleted head will disappear after the push we
are not really increasing the number of heads.

There is several case which will lead to extra being actually pushed. But this
first changeset aims to be simple. See the inline comment for details.

Without this change, you need to push --force every time you want to
push a newer version which is very error prone.

The remote side still display +n heads on unbundle because it does not have the
obsolete marker at unbundle time.

  $ hg init

  $ touch a
  $ hg add a
  $ hg commit -m "Added a"

  $ touch main
  $ hg add main
  $ hg commit -m "Added main"
  $ hg checkout 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

'main' should be gone:

  $ ls
  a

  $ touch side1
  $ hg add side1
  $ hg commit -m "Added side1"
  created new head
  $ touch side2
  $ hg add side2
  $ hg commit -m "Added side2"

  $ hg log
  changeset:   3:91ebc10ed028
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added side2
  
  changeset:   2:b932d7dbb1e1
  parent:      0:c2eda428b523
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added side1
  
  changeset:   1:71a760306caf
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added main
  
  changeset:   0:c2eda428b523
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added a
  

  $ hg heads
  changeset:   3:91ebc10ed028
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added side2
  
  changeset:   1:71a760306caf
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     Added main
  
  $ ls
  a
  side1
  side2

  $ hg update --debug -C 1
  resolving manifests
   overwrite: True, partial: False
   ancestor: 91ebc10ed028+, local: 91ebc10ed028+, remote: 71a760306caf
   side2: other deleted -> r
   side1: other deleted -> r
   main: remote created -> g
  updating: side1 1/3 files (33.33%)
  removing side1
  updating: side2 2/3 files (66.67%)
  removing side2
  updating: main 3/3 files (100.00%)
  getting main
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved

  $ ls
  a
  main