Revert "bpo-45160: Ttk optionmenu only set variable once (GH-28291) (GH-29132)"

This reverts commit 04485ac.

Author: ambv

Lib/tkinter/test/test_ttk/test_extensions.py

@@ -301,19 +301,6 @@ def test_unique_radiobuttons(self):
         optmenu.destroy()
         optmenu2.destroy()
 
-    def test_trace_variable(self):
-        # prior to bpo45160, tracing a variable would cause the callback to be made twice
-        success = []
-        items = ('a', 'b', 'c')
-        textvar = tkinter.StringVar(self.root)
-        def cb_test(*args):
-            self.assertEqual(textvar.get(), items[1])
-            success.append(True)
-        optmenu = ttk.OptionMenu(self.root, textvar, "a", *items)
-        textvar.trace("w", cb_test)
-        optmenu['menu'].invoke(1)
-        self.assertEqual(success, [True])
-
 
 class DefaultRootTest(AbstractDefaultRootTest, unittest.TestCase):
 

Lib/tkinter/ttk.py

@@ -1643,10 +1643,7 @@ def set_menu(self, default=None, *values):
         menu.delete(0, 'end')
         for val in values:
             menu.add_radiobutton(label=val,
-                command=(
-                    None if self._callback is None
-                    else lambda val=val: self._callback(val)
-                ),
+                command=tkinter._setit(self._variable, val, self._callback),
                 variable=self._variable)
 
         if default: