--- a/contrib/base-revsets.txt	Fri Apr 12 16:25:59 2019 +0200
+++ b/contrib/base-revsets.txt	Thu Apr 04 13:46:49 2019 +0200
@@ -47,3 +47,6 @@
 # The one below is used by rebase
 (children(ancestor(tip~5, tip)) and ::(tip~5))::
 heads(commonancestors(last(head(), 2)))
+heads(-10000:-1)
+roots(-10000:-1)
+only(max(head()), min(head()))