--- a/tests/test-log.t	Tue Jan 08 14:16:49 2013 +0100
+++ b/tests/test-log.t	Tue Jan 08 17:31:00 2013 +0100
@@ -1162,6 +1162,20 @@
   1:a765632148dc55d38c35c4f247c618701886cb2f
   0:9f758d63dcde62d547ebfb08e1e7ee96535f2b05
 
+test that parent prevent a changeset to be hidden
+
+  $ hg up 1 -q
+  $ hg log --template='{rev}:{node}\n'
+  1:a765632148dc55d38c35c4f247c618701886cb2f
+  0:9f758d63dcde62d547ebfb08e1e7ee96535f2b05
+
+test that second parent prevent a changeset to be hidden too
+
+  $ hg debugsetparents 0 1 # nothing suitable to merge here
+  $ hg log --template='{rev}:{node}\n'
+  1:a765632148dc55d38c35c4f247c618701886cb2f
+  0:9f758d63dcde62d547ebfb08e1e7ee96535f2b05
+
 clear extensions configuration
   $ echo '[extensions]' >> $HGRCPATH
   $ echo "obs=!" >> $HGRCPATH