diff --git a/tests/test-exchange-obsmarkers-case-C1.t b/tests/test-exchange-obsmarkers-case-C1.t
new file mode 100644
--- /dev/null
+++ b/tests/test-exchange-obsmarkers-case-C1.t
@@ -0,0 +1,158 @@
+============================================
+Testing obsolescence markers push: Cases C.1
+============================================
+
+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 C: advanced case
+TestCase 1: Multiple pruned changeset atop each other
+Variants:
+# a: explicite push
+# b: bare push
+
+C.1 Multiple pruned changeset atop each other
+=============================================
+
+.. {{{
+..   ⊗ B
+..   |
+..   ⊗ A
+..   |
+..   ● O
+.. }}}
+..
+.. Marker exist from:
+..
+..  * A (prune)
+..  * B (prune)
+..
+.. Commands run:
+..
+..  * hg push -r O
+..  * hg push
+..
+.. Expected exchange:
+..
+..  * A (prune)
+..  * B (prune)
+
+Setup
+-----
+
+  $ . $TESTDIR/testlib/exchange-obsmarker-util.sh
+
+Initial
+
+  $ setuprepos C.1
+  creating test repo for test case C.1
+  - pulldest
+  - main
+  - pushdest
+  cd into `main` and proceed with env setup
+  $ cd main
+  $ mkcommit A
+  $ mkcommit B
+  $ hg prune -qd '0 0' '.~1'
+  $ hg prune -qd '0 0' .
+  $ hg log -G --hidden
+  x  f6fbb35d8ac9 (draft): B
+  |
+  x  f5bc6836db60 (draft): A
+  |
+  @  a9bdc8b26820 (public): O
+  
+  $ inspect_obsmarkers
+  obsstore content
+  ================
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  $ cd ..
+  $ cd ..
+
+  $ cp -R C.1 C.1.a
+  $ cp -R C.1 C.1.b
+
+Actual Test (explicit push)
+---------------------------
+
+  $ dotest C.1.a O
+  ## Running testcase C.1.a
+  # testing echange of "O" (a9bdc8b26820)
+  ## initial state
+  # obstore: main
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (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: 2 new obsolescence markers
+  ## post push state
+  # obstore: main
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pushdest
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pulldest
+  ## pulling "a9bdc8b26820" from main into pulldest
+  pulling from main
+  no changes found
+  2 new obsolescence markers
+  ## post pull state
+  # obstore: main
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pushdest
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pulldest
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+
+Actual Test (bare push)
+-------------------------------------
+
+  $ dotest C.1.b
+  ## Running testcase C.1.b
+  ## initial state
+  # obstore: main
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (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: 2 new obsolescence markers
+  ## post push state
+  # obstore: main
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pushdest
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (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
+  2 new obsolescence markers
+  ## post pull state
+  # obstore: main
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pushdest
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  # obstore: pulldest
+  f5bc6836db60e308a17ba08bf050154ba9c4fad7 0 {a9bdc8b26820b1b87d585b82eb0ceb4a2ecdbc04} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  f6fbb35d8ac958bbe70035e4c789c18471cdc0af 0 {f5bc6836db60e308a17ba08bf050154ba9c4fad7} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}