diff --git a/tests/test-exchange-obsmarkers-case-B4.t b/tests/test-exchange-obsmarkers-case-B4.t
new file mode 100644
--- /dev/null
+++ b/tests/test-exchange-obsmarkers-case-B4.t
@@ -0,0 +1,163 @@
+============================================
+Testing obsolescence markers push: Cases B.4
+============================================
+
+Mercurial pushes obsolescences markers relevant to the "pushed-set", the set of
+all changesets that requested to be "in sync" after the push (even if they are
+already on both side).
+
+This test belongs to a series of tests checking such set is properly computed
+and applied. This does not tests "obsmarkers" discovery capabilities.
+
+Category B: pruning case
+TestCase 4: Pruned changeset on common part of the history
+Variants:
+# a: explicite push
+# b: bare push
+
+B.4 Pruned changeset on common part of history
+=============================================
+
+.. {{{
+..   ⊗ C
+..   | ● B
+..   | |
+..   | ● A
+..   |/
+..   ● O
+.. }}}
+..
+.. Marker exist from:
+..
+..  * C (prune)
+..
+.. Command run:
+..
+..  * hg push -r B
+..  * hg push
+..
+.. Expected exchange:
+..
+..  * prune for C
+
+Setup
+-----
+
+  $ . $TESTDIR/testlib/exchange-obsmarker-util.sh
+
+initial
+
+  $ setuprepos B.4
+  creating test repo for test case B.4
+  - pulldest
+  - main
+  - pushdest
+  cd into `main` and proceed with env setup
+  $ cd main
+  $ mkcommit A
+  $ mkcommit B
+  $ hg phase --public .
+  $ hg push ../pushdest
+  pushing to ../pushdest
+  searching for changes
+  remote: adding changesets
+  remote: adding manifests
+  remote: adding file changes
+  remote: added 2 changesets with 2 changes to 2 files
+  $ hg push ../pulldest
+  pushing to ../pulldest
+  searching for changes
+  remote: adding changesets
+  remote: adding manifests
+  remote: adding file changes
+  remote: added 2 changesets with 2 changes to 2 files
+  $ hg update -q 0
+  $ mkcommit C
+  created new head
+  $ hg prune -qd '0 0' .
+  $ hg log -G --hidden
+  x  7f7f229b13a6 (draft): C
+  |
+  | o  f6fbb35d8ac9 (public): B
+  | |
+  | o  f5bc6836db60 (public): A
+  |/
+  @  a9bdc8b26820 (public): O
+  
+  $ inspect_obsmarkers
+  obsstore content
+  ================
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  $ cd ..
+  $ cd ..
+
+  $ cp -R B.4 B.4.a
+  $ cp -R B.4 B.4.b
+
+Actual Test (explicit push version)
+-----------------------------------
+
+  $ dotest B.4.a O
+  ## Running testcase B.4.a
+  # testing echange of "O" (a9bdc8b26820)
+  ## initial state
+  # obstore: main
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pushdest
+  # obstore: pulldest
+  ## pushing "O" from main to pushdest
+  pushing to pushdest
+  searching for changes
+  no changes found
+  remote: 1 new obsolescence markers
+  ## post push state
+  # obstore: main
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pushdest
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pulldest
+  ## pulling "a9bdc8b26820" from main into pulldest
+  pulling from main
+  no changes found
+  1 new obsolescence markers
+  ## post pull state
+  # obstore: main
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pushdest
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pulldest
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+
+Actual Test (bare push version)
+-----------------------------------
+
+  $ dotest B.4.b
+  ## Running testcase B.4.b
+  ## initial state
+  # obstore: main
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pushdest
+  # obstore: pulldest
+  ## pushing from main to pushdest
+  pushing to pushdest
+  searching for changes
+  no changes found
+  remote: 1 new obsolescence markers
+  ## post push state
+  # obstore: main
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pushdest
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pulldest
+  ## pulling from main into pulldest
+  pulling from main
+  searching for changes
+  no changes found
+  1 new obsolescence markers
+  ## post pull state
+  # obstore: main
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pushdest
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pulldest
+  7f7f229b13a629a5b20581c6cb723f4e2ca54bed 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}