Issue #22236: Tkinter tests now don't reuse default root window. New root

window is created for every test class.

Fixed Tkinter images copying operations in NoDefaultRoot mode.

Tcl command names generated for "after" callbacks now contains a name of
original function.

Lib/test/test_ttk_guionly.py

@@ -6,7 +6,7 @@ from test import support
 support.import_module('_tkinter')
 
 # Make sure tkinter._fix runs to set up the environment
-support.import_fresh_module('tkinter')
+tkinter = support.import_fresh_module('tkinter')
 
 # Skip test if tk cannot be initialized.
 support.requires('gui')
@@ -14,20 +14,24 @@ support.requires('gui')
 from _tkinter import TclError
 from tkinter import ttk
 from tkinter.test import runtktests
-from tkinter.test.support import get_tk_root
 
+root = None
 try:
-    ttk.Button()
+    root = tkinter.Tk()
+    button = ttk.Button(root)
+    button.destroy()
+    del button
 except TclError as msg:
     # assuming ttk is not available
     raise unittest.SkipTest("ttk not available: %s" % msg)
+finally:
+    if root is not None:
+        root.destroy()
+    del root
 
 def test_main():
-    try:
-        support.run_unittest(
-                *runtktests.get_tests(text=False, packages=['test_ttk']))
-    finally:
-        get_tk_root().destroy()
+    support.run_unittest(
+            *runtktests.get_tests(text=False, packages=['test_ttk']))
 
 if __name__ == '__main__':
     test_main()

Lib/tkinter/__init__.py

@@ -562,6 +562,7 @@ class Misc:
                         self.deletecommand(name)
                     except TclError:
                         pass
+            callit.__name__ = func.__name__
             name = self._register(callit)
             return self.tk.call('after', ms, name)
     def after_idle(self, func, *args):
@@ -3351,7 +3352,7 @@ class Image:
             master = _default_root
             if not master:
                 raise RuntimeError('Too early to create image')
-        self.tk = master.tk
+        self.tk = getattr(master, 'tk', master)
         if not name:
             Image._last_id += 1
             name = "pyimage%r" % (Image._last_id,) # tk itself would use image<x>
@@ -3422,20 +3423,20 @@ class PhotoImage(Image):
     # XXX copy -from, -to, ...?
     def copy(self):
         """Return a new PhotoImage with the same image as this widget."""
-        destImage = PhotoImage()
+        destImage = PhotoImage(master=self.tk)
         self.tk.call(destImage, 'copy', self.name)
         return destImage
     def zoom(self,x,y=''):
         """Return a new PhotoImage with the same image as this widget
         but zoom it with X and Y."""
-        destImage = PhotoImage()
+        destImage = PhotoImage(master=self.tk)
         if y=='': y=x
         self.tk.call(destImage, 'copy', self.name, '-zoom',x,y)
         return destImage
     def subsample(self,x,y=''):
         """Return a new PhotoImage based on the same image as this widget
         but use only every Xth or Yth pixel."""
-        destImage = PhotoImage()
+        destImage = PhotoImage(master=self.tk)
         if y=='': y=x
         self.tk.call(destImage, 'copy', self.name, '-subsample',x,y)
         return destImage

Lib/tkinter/test/support.py

@@ -3,30 +3,43 @@ import tkinter
 import unittest
 from test.support import requires
 
-def get_tk_root():
-    requires('gui')             # raise exception if tk unavailable
-    try:
-        root = tkinter._default_root
-    except AttributeError:
-        # it is possible to disable default root in Tkinter, although
-        # I haven't seen people doing it (but apparently someone did it
-        # here).
-        root = None
+class AbstractTkTest:
 
-    if root is None:
-        # create a new master only if there isn't one already
-        root = tkinter.Tk()
+    @classmethod
+    def setUpClass(cls):
+        cls._old_support_default_root = tkinter._support_default_root
+        destroy_default_root()
+        tkinter.NoDefaultRoot()
+        cls.root = tkinter.Tk()
+        cls.wantobjects = cls.root.wantobjects()
+        # De-maximize main window.
+        # Some window managers can maximize new windows.
+        cls.root.wm_state('normal')
+        try:
+            cls.root.wm_attributes('-zoomed', False)
+        except tkinter.TclError:
+            pass
 
-    return root
+    @classmethod
+    def tearDownClass(cls):
+        cls.root.destroy()
+        cls.root = None
+        tkinter._default_root = None
+        tkinter._support_default_root = cls._old_support_default_root
 
-def root_deiconify():
-    root = get_tk_root()
-    root.deiconify()
+    def setUp(self):
+        self.root.deiconify()
 
-def root_withdraw():
-    root = get_tk_root()
-    root.withdraw()
+    def tearDown(self):
+        for w in self.root.winfo_children():
+            w.destroy()
+        self.root.withdraw()
 
+def destroy_default_root():
+    if getattr(tkinter, '_default_root', None):
+        tkinter._default_root.update_idletasks()
+        tkinter._default_root.destroy()
+        tkinter._default_root = None
 
 def simulate_mouse_click(widget, x, y):
     """Generate proper events to click at the x, y position (tries to act

Lib/tkinter/test/test_tkinter/test_font.py

@@ -2,26 +2,20 @@ import unittest
 import tkinter
 from tkinter import font
 from test.support import requires, run_unittest
-import tkinter.test.support as support
+from tkinter.test.support import AbstractTkTest
 
 requires('gui')
 
-class FontTest(unittest.TestCase):
-
-    def setUp(self):
-        support.root_deiconify()
-
-    def tearDown(self):
-        support.root_withdraw()
+class FontTest(AbstractTkTest, unittest.TestCase):
 
     def test_font_eq(self):
         fontname = "TkDefaultFont"
         try:
-            f = font.Font(name=fontname, exists=True)
+            f = font.Font(root=self.root, name=fontname, exists=True)
         except tkinter._tkinter.TclError:
-            f = font.Font(name=fontname, exists=False)
-        font1 = font.nametofont(fontname)
-        font2 = font.nametofont(fontname)
+            f = font.Font(root=self.root, name=fontname, exists=False)
+        font1 = font.Font(root=self.root, name=fontname, exists=True)
+        font2 = font.Font(root=self.root, name=fontname, exists=True)
         self.assertIsNot(font1, font2)
         self.assertEqual(font1, font2)
         self.assertNotEqual(font1, font1.copy())

Lib/tkinter/test/test_tkinter/test_geometry_managers.py

@@ -278,7 +278,7 @@ class PlaceTest(AbstractWidgetTest, unittest.TestCase):
 
     def create2(self):
         t = tkinter.Toplevel(self.root, width=300, height=200, bd=0)
-        t.wm_geometry('+0+0')
+        t.wm_geometry('300x200+0+0')
         f = tkinter.Frame(t, width=154, height=84, bd=2, relief='raised')
         f.place_configure(x=48, y=38)
         f2 = tkinter.Frame(t, width=30, height=60, bd=2, relief='raised')
@@ -479,7 +479,6 @@ class PlaceTest(AbstractWidgetTest, unittest.TestCase):
 class GridTest(AbstractWidgetTest, unittest.TestCase):
 
     def tearDown(self):
-        super().tearDown()
         cols, rows = self.root.grid_size()
         for i in range(cols + 1):
             self.root.grid_columnconfigure(i, weight=0, minsize=0, pad=0, uniform='')
@@ -488,10 +487,10 @@ class GridTest(AbstractWidgetTest, unittest.TestCase):
         self.root.grid_propagate(1)
         if tcl_version >= (8, 5):
             self.root.grid_anchor('nw')
+        super().tearDown()
 
     def test_grid_configure(self):
         b = tkinter.Button(self.root)
-        self.addCleanup(b.destroy)
         self.assertEqual(b.grid_info(), {})
         b.grid_configure()
         self.assertEqual(b.grid_info()['in'], self.root)
@@ -578,7 +577,6 @@ class GridTest(AbstractWidgetTest, unittest.TestCase):
 
     def test_grid_configure_row(self):
         b = tkinter.Button(self.root)
-        self.addCleanup(b.destroy)
         with self.assertRaisesRegex(TclError, 'bad (row|grid) value "-1": '
                                     'must be a non-negative integer'):
             b.grid_configure(row=-1)
@@ -795,7 +793,7 @@ class GridTest(AbstractWidgetTest, unittest.TestCase):
             self.root.grid_bbox(0, 0, 0, 'x')
         with self.assertRaises(TypeError):
             self.root.grid_bbox(0, 0, 0, 0, 0)
-        t = tkinter.Toplevel(self.root)
+        t = self.root
         # de-maximize
         t.wm_geometry('1x1+0+0')
         t.wm_geometry('')
@@ -823,7 +821,7 @@ class GridTest(AbstractWidgetTest, unittest.TestCase):
             self.root.grid_location('x', 'y')
         with self.assertRaisesRegex(TclError, 'bad screen distance "y"'):
             self.root.grid_location('1c', 'y')
-        t = tkinter.Toplevel(self.root)
+        t = self.root
         # de-maximize
         t.wm_geometry('1x1+0+0')
         t.wm_geometry('')

Lib/tkinter/test/test_tkinter/test_images.py

 import unittest
 import tkinter
-from tkinter import ttk
 from test import support
-from tkinter.test.support import requires_tcl
+from tkinter.test.support import AbstractTkTest, requires_tcl
 
 support.requires('gui')
 
 
-class MiscTest(unittest.TestCase):
-
-    def setUp(self):
-        self.root = ttk.setup_master()
+class MiscTest(AbstractTkTest, unittest.TestCase):
 
     def test_image_types(self):
         image_types = self.root.image_types()
@@ -23,15 +19,13 @@ class MiscTest(unittest.TestCase):
         self.assertIsInstance(image_names, tuple)
 
 
-class BitmapImageTest(unittest.TestCase):
+class BitmapImageTest(AbstractTkTest, unittest.TestCase):
 
     @classmethod
     def setUpClass(cls):
+        AbstractTkTest.setUpClass.__func__(cls)
         cls.testfile = support.findfile('python.xbm', subdir='imghdrdata')
 
-    def setUp(self):
-        self.root = ttk.setup_master()
-
     def test_create_from_file(self):
         image = tkinter.BitmapImage('::img::test', master=self.root,
                                     foreground='yellow', background='blue',
@@ -107,16 +101,13 @@ class BitmapImageTest(unittest.TestCase):
                          '-foreground {} {} #000000 yellow')
 
 
-class PhotoImageTest(unittest.TestCase):
+class PhotoImageTest(AbstractTkTest, unittest.TestCase):
 
     @classmethod
     def setUpClass(cls):
+        AbstractTkTest.setUpClass.__func__(cls)
         cls.testfile = support.findfile('python.gif', subdir='imghdrdata')
 
-    def setUp(self):
-        self.root = ttk.setup_master()
-        self.wantobjects = self.root.wantobjects()
-
     def create(self):
         return tkinter.PhotoImage('::img::test', master=self.root,
                                   file=self.testfile)

Lib/tkinter/test/test_tkinter/test_misc.py

 import unittest
 import tkinter
-from tkinter import ttk
 from test import support
+from tkinter.test.support import AbstractTkTest
 
 support.requires('gui')
 
-class MiscTest(unittest.TestCase):
-
-    def setUp(self):
-        self.root = ttk.setup_master()
+class MiscTest(AbstractTkTest, unittest.TestCase):
 
     def test_tk_setPalette(self):
         root = self.root

Lib/tkinter/test/test_tkinter/test_text.py

 import unittest
 import tkinter
 from test.support import requires, run_unittest
-from tkinter.ttk import setup_master
+from tkinter.test.support import AbstractTkTest
 
 requires('gui')
 
-class TextTest(unittest.TestCase):
+class TextTest(AbstractTkTest, unittest.TestCase):
 
     def setUp(self):
-        self.root = setup_master()
+        super().setUp()
         self.text = tkinter.Text(self.root)
 
-    def tearDown(self):
-        self.text.destroy()
-
     def test_debug(self):
         text = self.text
         olddebug = text.debug()

Lib/tkinter/test/test_tkinter/test_variables.py

 import unittest
 
-from tkinter import Variable, StringVar, IntVar, DoubleVar, BooleanVar, Tk
+from tkinter import Variable, StringVar, IntVar, DoubleVar, BooleanVar, Tcl
 
 
 class Var(Variable):
@@ -16,10 +16,10 @@ class Var(Variable):
 class TestBase(unittest.TestCase):
 
     def setUp(self):
-        self.root = Tk()
+        self.root = Tcl()
 
     def tearDown(self):
-        self.root.destroy()
+        del self.root
 
 
 class TestVariable(TestBase):
@@ -81,7 +81,7 @@ class TestVariable(TestBase):
             self.root.setvar(b'var\x00name', "value")
 
     def test_initialize(self):
-        v = Var()
+        v = Var(self.root)
         self.assertFalse(v.side_effect)
         v.set("value")
         self.assertTrue(v.side_effect)

Lib/tkinter/test/test_tkinter/test_widgets.py

@@ -66,7 +66,7 @@ class ToplevelTest(AbstractToplevelTest, unittest.TestCase):
         'takefocus', 'use', 'visual', 'width',
     )
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Toplevel(self.root, **kwargs)
 
     def test_menu(self):
@@ -105,7 +105,7 @@ class FrameTest(AbstractToplevelTest, unittest.TestCase):
         'relief', 'takefocus', 'visual', 'width',
     )
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Frame(self.root, **kwargs)
 
 
@@ -120,7 +120,7 @@ class LabelFrameTest(AbstractToplevelTest, unittest.TestCase):
         'takefocus', 'text', 'visual', 'width',
     )
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.LabelFrame(self.root, **kwargs)
 
     def test_labelanchor(self):
@@ -158,7 +158,7 @@ class LabelTest(AbstractLabelTest, unittest.TestCase):
         'underline', 'width', 'wraplength',
     )
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Label(self.root, **kwargs)
 
 
@@ -175,7 +175,7 @@ class ButtonTest(AbstractLabelTest, unittest.TestCase):
         'state', 'takefocus', 'text', 'textvariable',
         'underline', 'width', 'wraplength')
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Button(self.root, **kwargs)
 
     def test_default(self):
@@ -199,7 +199,7 @@ class CheckbuttonTest(AbstractLabelTest, unittest.TestCase):
         'underline', 'variable', 'width', 'wraplength',
     )
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Checkbutton(self.root, **kwargs)
 
 
@@ -227,7 +227,7 @@ class RadiobuttonTest(AbstractLabelTest, unittest.TestCase):
         'underline', 'value', 'variable', 'width', 'wraplength',
     )
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Radiobutton(self.root, **kwargs)
 
     def test_value(self):
@@ -250,7 +250,7 @@ class MenubuttonTest(AbstractLabelTest, unittest.TestCase):
     )
     _conv_pixels = staticmethod(pixels_round)
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Menubutton(self.root, **kwargs)
 
     def test_direction(self):
@@ -268,7 +268,7 @@ class MenubuttonTest(AbstractLabelTest, unittest.TestCase):
                      'crashes with Cocoa Tk (issue19733)')
     def test_image(self):
         widget = self.create()
-        image = tkinter.PhotoImage('image1')
+        image = tkinter.PhotoImage(master=self.root, name='image1')
         self.checkParam(widget, 'image', image, conv=str)
         errmsg = 'image "spam" doesn\'t exist'
         with self.assertRaises(tkinter.TclError) as cm:
@@ -303,7 +303,7 @@ class MenubuttonTest(AbstractLabelTest, unittest.TestCase):
 
 class OptionMenuTest(MenubuttonTest, unittest.TestCase):
 
-    def _create(self, default='b', values=('a', 'b', 'c'), **kwargs):
+    def create(self, default='b', values=('a', 'b', 'c'), **kwargs):
         return tkinter.OptionMenu(self.root, None, default, *values, **kwargs)
 
 
@@ -322,7 +322,7 @@ class EntryTest(AbstractWidgetTest, unittest.TestCase):
         'validate', 'validatecommand', 'width', 'xscrollcommand',
     )
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Entry(self.root, **kwargs)
 
     def test_disabledbackground(self):
@@ -396,7 +396,7 @@ class SpinboxTest(EntryTest, unittest.TestCase):
         'width', 'wrap', 'xscrollcommand',
     )
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Spinbox(self.root, **kwargs)
 
     test_show = None
@@ -490,9 +490,9 @@ class TextTest(AbstractWidgetTest, unittest.TestCase):
         'xscrollcommand', 'yscrollcommand',
     )
     if tcl_version < (8, 5):
-        wantobjects = False
+        _stringify = True
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Text(self.root, **kwargs)
 
     def test_autoseparators(self):
@@ -644,9 +644,9 @@ class CanvasTest(AbstractWidgetTest, unittest.TestCase):
     )
 
     _conv_pixels = round
-    wantobjects = False
+    _stringify = True
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Canvas(self.root, **kwargs)
 
     def test_closeenough(self):
@@ -699,7 +699,7 @@ class ListboxTest(AbstractWidgetTest, unittest.TestCase):
         'takefocus', 'width', 'xscrollcommand', 'yscrollcommand',
     )
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Listbox(self.root, **kwargs)
 
     def test_activestyle(self):
@@ -709,7 +709,7 @@ class ListboxTest(AbstractWidgetTest, unittest.TestCase):
 
     def test_listvariable(self):
         widget = self.create()
-        var = tkinter.DoubleVar()
+        var = tkinter.DoubleVar(self.root)
         self.checkVariableParam(widget, 'listvariable', var)
 
     def test_selectmode(self):
@@ -831,7 +831,7 @@ class ScaleTest(AbstractWidgetTest, unittest.TestCase):
     )
     default_orient = 'vertical'
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Scale(self.root, **kwargs)
 
     def test_bigincrement(self):
@@ -897,10 +897,10 @@ class ScrollbarTest(AbstractWidgetTest, unittest.TestCase):
         'takefocus', 'troughcolor', 'width',
     )
     _conv_pixels = round
-    wantobjects = False
+    _stringify = True
     default_orient = 'vertical'
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Scrollbar(self.root, **kwargs)
 
     def test_activerelief(self):
@@ -946,7 +946,7 @@ class PanedWindowTest(AbstractWidgetTest, unittest.TestCase):
     )
     default_orient = 'horizontal'
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.PanedWindow(self.root, **kwargs)
 
     def test_handlepad(self):
@@ -1104,7 +1104,7 @@ class MenuTest(AbstractWidgetTest, unittest.TestCase):
     )
     _conv_pixels = noconv
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Menu(self.root, **kwargs)
 
     def test_postcommand(self):
@@ -1173,7 +1173,7 @@ class MessageTest(AbstractWidgetTest, unittest.TestCase):
     )
     _conv_pad_pixels = noconv
 
-    def _create(self, **kwargs):
+    def create(self, **kwargs):
         return tkinter.Message(self.root, **kwargs)
 
     def test_aspect(self):

Lib/tkinter/test/test_ttk/test_style.py

@@ -2,15 +2,15 @@ import unittest
 import tkinter
 from tkinter import ttk
 from test.support import requires, run_unittest
-
-import tkinter.test.support as support
+from tkinter.test.support import AbstractTkTest
 
 requires('gui')
 
-class StyleTest(unittest.TestCase):
+class StyleTest(AbstractTkTest, unittest.TestCase):
 
     def setUp(self):
-        self.style = ttk.Style()
+        super().setUp()
+        self.style = ttk.Style(self.root)
 
 
     def test_configure(self):
@@ -25,7 +25,7 @@ class StyleTest(unittest.TestCase):
         style = self.style
         style.map('TButton', background=[('active', 'background', 'blue')])
         self.assertEqual(style.map('TButton', 'background'),
-            [('active', 'background', 'blue')] if style.tk.wantobjects() else
+            [('active', 'background', 'blue')] if self.wantobjects else
             [('active background', 'blue')])
         self.assertIsInstance(style.map('TButton'), dict)
 

Lib/tkinter/test/widget_tests.py

@@ -3,9 +3,9 @@
 import unittest
 import sys
 import tkinter
-from tkinter.ttk import setup_master, Scale
-from tkinter.test.support import (tcl_version, requires_tcl, get_tk_patchlevel,
-                                  pixels_conv, tcl_obj_eq)
+from tkinter.ttk import Scale
+from tkinter.test.support import (AbstractTkTest, tcl_version, requires_tcl,
+                                  get_tk_patchlevel, pixels_conv, tcl_obj_eq)
 import test.support
 
 
@@ -22,33 +22,26 @@ if get_tk_patchlevel()[:3] == (8, 5, 11):
 
 _sentinel = object()
 
-class AbstractWidgetTest:
+class AbstractWidgetTest(AbstractTkTest):
     _conv_pixels = staticmethod(pixels_round)
     _conv_pad_pixels = None
-    wantobjects = True
+    _stringify = False
 
-    def setUp(self):
-        self.root = setup_master()
-        self.scaling = float(self.root.call('tk', 'scaling'))
-        if not self.root.wantobjects():
-            self.wantobjects = False
-
-    def tearDown(self):
-        for w in self.root.winfo_children():
-            w.destroy()
+    @property
+    def scaling(self):
+        try:
+            return self._scaling
+        except AttributeError:
+            self._scaling = float(self.root.call('tk', 'scaling'))
+            return self._scaling
 
     def _str(self, value):
-        if self.wantobjects and tcl_version >= (8, 6):
+        if not self._stringify and self.wantobjects and tcl_version >= (8, 6):
             return value
         if isinstance(value, tuple):
             return ' '.join(map(self._str, value))
         return str(value)
 
-    def create(self, **kwargs):
-        widget = self._create(**kwargs)
-        self.addCleanup(widget.destroy)
-        return widget
-
     def assertEqual2(self, actual, expected, msg=None, eq=object.__eq__):
         if eq(actual, expected):
             return
@@ -61,7 +54,7 @@ class AbstractWidgetTest:
             expected = value
         if conv:
             expected = conv(expected)
-        if not self.wantobjects:
+        if self._stringify or not self.wantobjects:
             if isinstance(expected, tuple):
                 expected = tkinter._join(expected)
             else:
@@ -193,7 +186,7 @@ class AbstractWidgetTest:
                 errmsg=errmsg)
 
     def checkImageParam(self, widget, name):
-        image = tkinter.PhotoImage('image1')
+        image = tkinter.PhotoImage(master=self.root, name='image1')
         self.checkParam(widget, name, image, conv=str)
         self.checkInvalidParam(widget, name, 'spam',
                 errmsg='image "spam" doesn\'t exist')
@@ -414,7 +407,7 @@ class StandardOptionsTests:
 
     def test_textvariable(self):
         widget = self.create()
-        var = tkinter.StringVar()
+        var = tkinter.StringVar(self.root)
         self.checkVariableParam(widget, 'textvariable', var)
 
     def test_troughcolor(self):
@@ -475,7 +468,7 @@ class StandardOptionsTests:
 
     def test_variable(self):
         widget = self.create()
-        var = tkinter.DoubleVar()
+        var = tkinter.DoubleVar(self.root)
         self.checkVariableParam(widget, 'variable', var)
 
 

Misc/NEWS

@@ -27,7 +27,9 @@ Core and Builtins
 Library
 -------
 
--- Issue #22191: Fix warnings.__all__.
+- Issue #22236: Fixed Tkinter images copying operations in NoDefaultRoot mode.
+
+- Issue #22191: Fix warnings.__all__.
 
 - Issue #15696: Add a __sizeof__ implementation for mmap objects on Windows.
 
@@ -279,6 +281,9 @@ IDLE
 Tests
 -----
 
+- Issue #22236: Tkinter tests now don't reuse default root window.  New root
+  window is created for every test class.
+
 - Issue #20746: Fix test_pdb to run in refleak mode (-R).  Patch by Xavier
   de Gaye.