--- a/mercurial/cmdutil.py	Sat Apr 22 14:53:05 2017 +0900
+++ b/mercurial/cmdutil.py	Sat Apr 22 15:06:06 2017 +0900
@@ -1580,15 +1580,8 @@
 
     def __init__(self, ui, repo, matchfn, diffopts, tmpl, mapfile, buffered):
         changeset_printer.__init__(self, ui, repo, matchfn, diffopts, buffered)
-        assert not (tmpl and mapfile)
-        defaulttempl = templatekw.defaulttempl
-        if mapfile:
-            self.t = templater.templater.frommapfile(mapfile,
-                                                     cache=defaulttempl)
-        else:
-            self.t = formatter.maketemplater(ui, 'changeset', tmpl,
-                                             cache=defaulttempl)
-
+        self.t = formatter.loadtemplater(ui, 'changeset', (tmpl, mapfile),
+                                         cache=templatekw.defaulttempl)
         self._counter = itertools.count()
         self.cache = {}