diff -r d2531a747ff5 -r b12ff7ef35b1 hgext/obsolete.py
--- a/hgext/obsolete.py	Thu Aug 23 12:51:06 2012 +0200
+++ b/hgext/obsolete.py	Thu Aug 23 12:53:27 2012 +0200
@@ -658,6 +658,8 @@
         ui.setconfig('alias', 'pstatus', 'status --rev .^')
     if ui.config('alias', 'pdiff', None) is None:
         ui.setconfig('alias', 'pdiff', 'diff --rev .^')
+    if ui.config('alias', 'olog', None) is None:
+        ui.setconfig('alias', 'olog', "log -r 'precursors(.)' --hidden")
 
 # - "troubles" method on changectx