bpo-39050: The Help button in IDLE's config menu works again (GH-17611)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

Lib/idlelib/NEWS.txt

@@ -3,6 +3,8 @@ Released on 2020-10-05?
 ======================================
 
 
+bpo-39050: Make Settings dialog Help button work again.
+
 bpo-32989: Add tests for editor newline_and_indent_event method.
 Remove dead code from pyparse find_good_parse_start method.
 

Lib/idlelib/configdialog.py

@@ -210,7 +210,7 @@ class ConfigDialog(Toplevel):
         """
         page = self.note.tab(self.note.select(), option='text').strip()
         view_text(self, title='Help for IDLE preferences',
-                 text=help_common+help_pages.get(page, ''))
+                  contents=help_common+help_pages.get(page, ''))
 
     def deactivate_current_config(self):
         """Remove current key bindings.

Lib/idlelib/idle_test/test_configdialog.py

@@ -47,6 +47,17 @@ def tearDownModule():
     root.destroy()
     root = dialog = None
 
+class ConfigDialogTest(unittest.TestCase):
+
+    def test_help(self):
+        dialog.note.select(dialog.keyspage)
+        saved = configdialog.view_text
+        view = configdialog.view_text = Func()
+        dialog.help()
+        s = view.kwds['contents']
+        self.assertTrue(s.startswith('When you click'))
+        self.assertTrue(s.endswith('a different name.\n'))
+        configdialog.view_text = saved
 
 class FontPageTest(unittest.TestCase):
     """Test that font widgets enable users to make font changes.

Misc/NEWS.d/next/IDLE/2020-01-22-22-28-06.bpo-39050.zkn0FO.rst

@@ -0,0 +1 @@
+Make IDLE Settings dialog Help button work again.