Issue #20743: Fix a reference leak in test_tcl.

Lib/test/test_tcl.py

@@ -376,6 +376,7 @@ class TclTest(unittest.TestCase):
             result = arg
             return arg
         self.interp.createcommand('testfunc', testfunc)
+        self.addCleanup(self.interp.tk.deletecommand, 'testfunc')
         def check(value, expected, eq=self.assertEqual):
             r = self.interp.call('testfunc', value)
             self.assertIsInstance(result, str)

Misc/NEWS

@@ -17,6 +17,11 @@ Library
 - Issue #19748: On AIX, time.mktime() now raises an OverflowError for year
   outsize range [1902; 2037].
 
+Tests
+-----
+
+- Issue #20743: Fix a reference leak in test_tcl.
+
 
 What's New in Python 3.4.0 release candidate 2?
 ===============================================