diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -822,7 +822,7 @@ class atomictempfile(object):
             self._fp.close()
             rename(self.temp, localpath(self.__name))
 
-    def __del__(self):
+    def close(self):
         if not self._fp:
             return
         if not self._fp.closed:
@@ -831,6 +831,9 @@ class atomictempfile(object):
             except: pass
             self._fp.close()
 
+    def __del__(self):
+        self.close()
+
 def makedirs(name, mode=None):
     """recursive directory creation with parent mode inheritance"""
     parent = os.path.abspath(os.path.dirname(name))