Issue #1342811: Fixed broken patch.

Backport from trunk r65971.

Lib/lib-tk/Tkinter.py

@@ -2672,7 +2672,9 @@ class Menu(Widget):
         if index2 is None:
             index2 = index1
         cmds = []
-        for i in range(self.index(index1), self.index(index2)+1):
+        (num_index1, num_index2) = (self.index(index1), self.index(index2))
+        if (num_index1 is not None) and (num_index2 is not None):
+            for i in range(num_index1, num_index2 + 1):
                 if 'command' in self.entryconfig(i):
                     c = str(self.entrycget(i, 'command'))
                     if c in self._tclCommands: