diff --git a/hgext/bugzilla.py b/hgext/bugzilla.py
--- a/hgext/bugzilla.py
+++ b/hgext/bugzilla.py
@@ -879,14 +879,13 @@ class bugzilla(object):
 
         mapfile = self.ui.config('bugzilla', 'style')
         tmpl = self.ui.config('bugzilla', 'template')
-        t = cmdutil.changeset_templater(self.ui, self.repo,
-                                        False, None, mapfile, False)
         if not mapfile and not tmpl:
             tmpl = _('changeset {node|short} in repo {root} refers '
                      'to bug {bug}.\ndetails:\n\t{desc|tabindent}')
         if tmpl:
             tmpl = templater.parsestring(tmpl, quoted=False)
-            t.use_template(tmpl)
+        t = cmdutil.changeset_templater(self.ui, self.repo,
+                                        False, None, tmpl, mapfile, False)
         self.ui.pushbuffer()
         t.show(ctx, changes=ctx.changeset(),
                bug=str(bugid),
diff --git a/hgext/churn.py b/hgext/churn.py
--- a/hgext/churn.py
+++ b/hgext/churn.py
@@ -18,10 +18,10 @@ testedwith = 'internal'
 def maketemplater(ui, repo, tmpl):
     tmpl = templater.parsestring(tmpl, quoted=False)
     try:
-        t = cmdutil.changeset_templater(ui, repo, False, None, None, False)
+        t = cmdutil.changeset_templater(ui, repo, False, None, tmpl,
+                                        None, False)
     except SyntaxError, inst:
         raise util.Abort(inst.args[0])
-    t.use_template(tmpl)
     return t
 
 def changedlines(ui, repo, ctx1, ctx2, fns):
diff --git a/hgext/hgcia.py b/hgext/hgcia.py
--- a/hgext/hgcia.py
+++ b/hgext/hgcia.py
@@ -202,8 +202,7 @@ class hgcia(object):
             template = self.diffstat and self.dstemplate or self.deftemplate
         template = templater.parsestring(template, quoted=False)
         t = cmdutil.changeset_templater(self.ui, self.repo, False, None,
-                                        style, False)
-        t.use_template(template)
+                                        template, style, False)
         self.templater = t
 
     def strip(self, path):
diff --git a/hgext/keyword.py b/hgext/keyword.py
--- a/hgext/keyword.py
+++ b/hgext/keyword.py
@@ -218,9 +218,8 @@ class kwtemplater(object):
         '''Replaces keywords in data with expanded template.'''
         def kwsub(mobj):
             kw = mobj.group(1)
-            ct = cmdutil.changeset_templater(self.ui, self.repo,
-                                             False, None, '', False)
-            ct.use_template(self.templates[kw])
+            ct = cmdutil.changeset_templater(self.ui, self.repo, False, None
+                                             self.templates[kw], '', False)
             self.ui.pushbuffer()
             ct.show(ctx, root=self.repo.root, file=path)
             ekw = templatefilters.firstline(self.ui.popbuffer())
diff --git a/hgext/notify.py b/hgext/notify.py
--- a/hgext/notify.py
+++ b/hgext/notify.py
@@ -188,13 +188,12 @@ class notifier(object):
         mapfile = self.ui.config('notify', 'style')
         template = (self.ui.config('notify', hooktype) or
                     self.ui.config('notify', 'template'))
-        self.t = cmdutil.changeset_templater(self.ui, self.repo,
-                                             False, None, mapfile, False)
         if not mapfile and not template:
             template = deftemplates.get(hooktype) or single_template
         if template:
             template = templater.parsestring(template, quoted=False)
-            self.t.use_template(template)
+        self.t = cmdutil.changeset_templater(self.ui, self.repo, False, None,
+                                             template, mapfile, False)
 
     def strip(self, path):
         '''strip leading slashes from local path, turn into web-safe path.'''
diff --git a/mercurial/cmdutil.py b/mercurial/cmdutil.py
--- a/mercurial/cmdutil.py
+++ b/mercurial/cmdutil.py
@@ -948,7 +948,7 @@ class changeset_printer(object):
 class changeset_templater(changeset_printer):
     '''format changeset information.'''
 
-    def __init__(self, ui, repo, patch, diffopts, mapfile, buffered):
+    def __init__(self, ui, repo, patch, diffopts, tmpl, mapfile, buffered):
         changeset_printer.__init__(self, ui, repo, patch, diffopts, buffered)
         formatnode = ui.debugflag and (lambda x: x) or (lambda x: x[:12])
         defaulttempl = {
@@ -961,11 +961,10 @@ class changeset_templater(changeset_prin
         defaulttempl['filecopy'] = defaulttempl['file_copy']
         self.t = templater.templater(mapfile, {'formatnode': formatnode},
                                      cache=defaulttempl)
-        self.cache = {}
+        if tmpl:
+            self.t.cache['changeset'] = tmpl
 
-    def use_template(self, t):
-        '''set template string to use'''
-        self.t.cache['changeset'] = t
+        self.cache = {}
 
     def _meaningful_parentrevs(self, ctx):
         """Return list of meaningful (or all if debug) parentrevs for rev.
@@ -1096,11 +1095,9 @@ def show_changeset(ui, repo, opts, buffe
         return changeset_printer(ui, repo, patch, opts, buffered)
 
     try:
-        t = changeset_templater(ui, repo, patch, opts, mapfile, buffered)
+        t = changeset_templater(ui, repo, patch, opts, tmpl, mapfile, buffered)
     except SyntaxError, inst:
         raise util.Abort(inst.args[0])
-    if tmpl:
-        t.use_template(tmpl)
     return t
 
 def showmarker(ui, marker):