--- a/tests/test-merge-default	Mon Feb 15 15:07:21 2010 -0500
+++ b/tests/test-merge-default	Mon Feb 15 15:25:29 2010 -0500
@@ -50,4 +50,11 @@
 echo % should fail because merge with other branch
 hg merge
 
+# Test for issue2043: ensure that 'merge -P' shows ancestors of 6 that
+# are not ancestors of 7, regardless of where their least common
+# ancestor is.
+echo % merge preview not affected by common ancestor
+hg up -q 7
+hg merge -q -P 6         # expect: 2, 4, 5, 6
+
 true