--- a/tests/bundles/test-revlog-diff-relative-to-nullrev.sh	Fri May 27 02:52:46 2022 +0200
+++ b/tests/bundles/test-revlog-diff-relative-to-nullrev.sh	Fri May 27 02:54:20 2022 +0200
@@ -29,6 +29,9 @@
 ../../../hg commit -Am root-B
 echo ho > a
 ../../../hg commit -Am child-A
+hg up null
+echo ha > a
+../../../hg commit -Am root-A
 ../../../hg debugdeltachain a
 rm -rf .hg/cache/ .hg/wcache/
 cd ..