IDLE - Capitalize search dialogs' 'Close' button label. (#13691)

It seems to be the only widget label not capitalized.

Lib/idlelib/idle_test/test_searchbase.py

@@ -32,6 +32,7 @@ class SearchDialogBaseTest(unittest.TestCase):
 
     @classmethod
     def tearDownClass(cls):
+        cls.root.update_idletasks()
         cls.root.destroy()
         del cls.root
 
@@ -149,7 +150,7 @@ class SearchDialogBaseTest(unittest.TestCase):
         # Look for close button command in buttonframe
         closebuttoncommand = ''
         for child in self.dialog.buttonframe.winfo_children():
-            if child['text'] == 'close':
+            if child['text'] == 'Close':
                 closebuttoncommand = child['command']
         self.assertIn('close', closebuttoncommand)
 

Lib/idlelib/searchbase.py

@@ -172,7 +172,7 @@ class SearchDialogBase:
         f = self.buttonframe = Frame(self.top)
         f.grid(row=0,column=2,padx=2,pady=2,ipadx=2,ipady=2)
 
-        b = self.make_button("close", self.close)
+        b = self.make_button("Close", self.close)
         b.lower()