--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-single-head-obsolescence-named-branch-A5.t	Fri Feb 18 14:27:43 2022 +0100
@@ -0,0 +1,108 @@
+=========================================
+Testing single head enforcement: Case A-5
+=========================================
+
+A repository is set to only accept a single head per name (typically named
+branch). However, obsolete changesets can make this enforcement more
+complicated, because they can be kept visible by other changeset on other
+branch.
+
+This case is part of a series of tests checking this behavior.
+
+Category A: Involving obsolescence
+TestCase 5: Obsoleting a merge reveals two heads
+
+.. old-state:
+..
+.. * 3 changesets on branch default (2 on their own branch + 1 merge)
+.. * 1 changeset on branch Z (children of the merge)
+..
+.. new-state:
+..
+.. * 2 changesets on branch default (merge is obsolete) each a head
+.. * 1 changeset on branch Z keeping the merge visible
+..
+.. expected-result:
+..
+.. * 2 heads detected (because we skip the merge)
+..
+.. graph-summary:
+..
+..   C ●      (branch Z)
+..     |
+..   M ⊗
+..     |\
+..   A ● ● B
+..     |/
+..     ●
+
+  $ . $TESTDIR/testlib/push-checkheads-util.sh
+
+  $ cat >> $HGRCPATH << EOF
+  > [command-templates]
+  > log = "{node|short} [{branch}] ({phase}): {desc}\n"
+  > EOF
+
+Test setup
+----------
+
+  $ mkdir A5
+  $ cd A5
+  $ setuprepos single-head
+  creating basic server and client repo
+  updating to branch default
+  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ cd client
+  $ hg up 0
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ mkcommit B0
+  created new head
+  $ hg merge
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  (branch merge, don't forget to commit)
+  $ hg ci -m 'M0'
+  $ hg branch Z
+  marked working directory as branch Z
+  (branches are permanent and global, did you want a bookmark?)
+  $ mkcommit C0
+  $ hg push --new-branch
+  pushing to $TESTTMP/A5/server
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 2 changes to 2 files
+  $ hg debugobsolete `getid "desc(M0)"` --record-parents
+  1 new obsolescence markers
+  obsoleted 1 changesets
+  1 new orphan changesets
+  $ hg heads
+  61c95483cc12 [Z] (draft): C0
+  74ff5441d343 [default] (draft): B0
+  8aaa48160adc [default] (draft): A0
+  $ hg log -G --hidden
+  @  61c95483cc12 [Z] (draft): C0
+  |
+  x    14d3d4d41d1a [default] (draft): M0
+  |\
+  | o  74ff5441d343 [default] (draft): B0
+  | |
+  o |  8aaa48160adc [default] (draft): A0
+  |/
+  o  1e4be0697311 [default] (public): root
+  
+
+Actual testing
+--------------
+
+(force push to make sure we get the changeset on the remote)
+
+  $ hg push -r 'desc("C0")' --force
+  pushing to $TESTTMP/A5/server
+  searching for changes
+  no changes found
+  transaction abort!
+  rollback completed
+  abort: rejecting multiple heads on branch "default"
+  (2 heads: 8aaa48160adc 74ff5441d343)
+  [255]