[PATCH 2 of 2] heads: enable pager

[Martin von Zweigbergk]

# HG changeset patch
# User Martin von Zweigbergk <martinvonz at google.com>
# Date 1489429164 25200
#      Mon Mar 13 11:19:24 2017 -0700
# Node ID 3d3109339b57341b333c1112beb41dd281fa944a
# Parent  f1f57e4e55e0afa73bddcef240b1ba10f66216b1
heads: enable pager

diff -r f1f57e4e55e0 -r 3d3109339b57 mercurial/commands.py
--- a/mercurial/commands.py	Mon Mar 13 11:03:59 2017 -0700
+++ b/mercurial/commands.py	Mon Mar 13 11:19:24 2017 -0700
@@ -2705,6 +2705,7 @@
     if not heads:
         return 1
 
+    ui.pager('heads')
     heads = sorted(heads, key=lambda x: -x.rev())
     displayer = cmdutil.show_changeset(ui, repo, opts)
     for ctx in heads: