--- a/tests/test-evolve-obshistory.t	Wed Apr 25 14:09:35 2018 +0100
+++ b/tests/test-evolve-obshistory.t	Fri Jun 08 22:52:52 2018 +0530
@@ -16,6 +16,23 @@
   > evolution.effect-flags = yes
   > EOF
 
+Test simple common cases
+========================
+
+Test setup
+----------
+  $ hg init $TESTTMP/simple
+  $ cd $TESTTMP/simple
+
+Actual test
+-----------
+  $ hg obslog -ap null
+  @  000000000000 (-1)
+  
+  $ hg obslog 'wdir()'
+  abort: working directory revision cannot be specified
+  [255]
+
 Test output on amended commit
 =============================