diff -r cc2382b60007 -r e518192d6bac mercurial/rcutil.py
--- a/mercurial/rcutil.py	Thu Apr 13 14:48:18 2017 -0400
+++ b/mercurial/rcutil.py	Thu Apr 13 08:27:19 2017 -0700
@@ -90,3 +90,9 @@
         _rccomponents.append(envrc)
         _rccomponents.extend(normpaths(userrcpath()))
     return _rccomponents
+
+def defaultpagerenv():
+    '''return a dict of default environment variables and their values,
+    intended to be set before starting a pager.
+    '''
+    return {'LESS': 'FRX', 'LV': '-c'}