bpo-42328: Fix tkinter.ttk.Style.map(). (GH-23300)

The function accepts now the representation of the default state as
empty sequence (as returned by Style.map()).
The structure of the result is now the same on all platform
and does not depend on the value of wantobjects.

Lib/tkinter/test/test_ttk/test_functions.py

@@ -137,6 +137,9 @@ class InternalFunctionsTest(unittest.TestCase):
         result = ttk._format_mapdict(opts)
         self.assertEqual(result, ('-üñíćódè', 'á vãl'))
 
+        self.assertEqual(ttk._format_mapdict({'opt': [('value',)]}),
+                         ('-opt', '{} value'))
+
         # empty states
         valid = {'opt': [('', '', 'hi')]}
         self.assertEqual(ttk._format_mapdict(valid), ('-opt', '{ } hi'))
@@ -159,10 +162,6 @@ class InternalFunctionsTest(unittest.TestCase):
         opts = {'a': None}
         self.assertRaises(TypeError, ttk._format_mapdict, opts)
 
-        # items in the value must have size >= 2
-        self.assertRaises(IndexError, ttk._format_mapdict,
-            {'a': [('invalid', )]})
-
 
     def test_format_elemcreate(self):
         self.assertTrue(ttk._format_elemcreate(None), (None, ()))

Lib/tkinter/test/test_ttk/test_style.py

@@ -1,11 +1,22 @@
 import unittest
 import tkinter
 from tkinter import ttk
+from test import support
 from test.support import requires, run_unittest
 from tkinter.test.support import AbstractTkTest
 
 requires('gui')
 
+CLASS_NAMES = [
+    '.', 'ComboboxPopdownFrame', 'Heading',
+    'Horizontal.TProgressbar', 'Horizontal.TScale', 'Item', 'Sash',
+    'TButton', 'TCheckbutton', 'TCombobox', 'TEntry',
+    'TLabelframe', 'TLabelframe.Label', 'TMenubutton',
+    'TNotebook', 'TNotebook.Tab', 'Toolbutton', 'TProgressbar',
+    'TRadiobutton', 'Treeview', 'TScale', 'TScrollbar', 'TSpinbox',
+    'Vertical.TProgressbar', 'Vertical.TScale'
+]
+
 class StyleTest(AbstractTkTest, unittest.TestCase):
 
     def setUp(self):
@@ -23,11 +34,36 @@ class StyleTest(AbstractTkTest, unittest.TestCase):
 
     def test_map(self):
         style = self.style
-        style.map('TButton', background=[('active', 'background', 'blue')])
-        self.assertEqual(style.map('TButton', 'background'),
-            [('active', 'background', 'blue')] if self.wantobjects else
-            [('active background', 'blue')])
-        self.assertIsInstance(style.map('TButton'), dict)
+
+        # Single state
+        for states in ['active'], [('active',)]:
+            with self.subTest(states=states):
+                style.map('TButton', background=[(*states, 'white')])
+                expected = [('active', 'white')]
+                self.assertEqual(style.map('TButton', 'background'), expected)
+                m = style.map('TButton')
+                self.assertIsInstance(m, dict)
+                self.assertEqual(m['background'], expected)
+
+        # Multiple states
+        for states in ['pressed', '!disabled'], ['pressed !disabled'], [('pressed', '!disabled')]:
+            with self.subTest(states=states):
+                style.map('TButton', background=[(*states, 'black')])
+                expected = [('pressed', '!disabled', 'black')]
+                self.assertEqual(style.map('TButton', 'background'), expected)
+                m = style.map('TButton')
+                self.assertIsInstance(m, dict)
+                self.assertEqual(m['background'], expected)
+
+        # Default state
+        for states in [], [''], [()]:
+            with self.subTest(states=states):
+                style.map('TButton', background=[(*states, 'grey')])
+                expected = [('grey',)]
+                self.assertEqual(style.map('TButton', 'background'), expected)
+                m = style.map('TButton')
+                self.assertIsInstance(m, dict)
+                self.assertEqual(m['background'], expected)
 
 
     def test_lookup(self):
@@ -86,6 +122,50 @@ class StyleTest(AbstractTkTest, unittest.TestCase):
         self.style.theme_use(curr_theme)
 
 
+    def test_configure_custom_copy(self):
+        style = self.style
+
+        curr_theme = self.style.theme_use()
+        self.addCleanup(self.style.theme_use, curr_theme)
+        for theme in self.style.theme_names():
+            self.style.theme_use(theme)
+            for name in CLASS_NAMES:
+                default = style.configure(name)
+                if not default:
+                    continue
+                with self.subTest(theme=theme, name=name):
+                    if support.verbose >= 2:
+                        print('configure', theme, name, default)
+                    newname = f'C.{name}'
+                    self.assertEqual(style.configure(newname), None)
+                    style.configure(newname, **default)
+                    self.assertEqual(style.configure(newname), default)
+                    for key, value in default.items():
+                        self.assertEqual(style.configure(newname, key), value)
+
+
+    def test_map_custom_copy(self):
+        style = self.style
+
+        curr_theme = self.style.theme_use()
+        self.addCleanup(self.style.theme_use, curr_theme)
+        for theme in self.style.theme_names():
+            self.style.theme_use(theme)
+            for name in CLASS_NAMES:
+                default = style.map(name)
+                if not default:
+                    continue
+                with self.subTest(theme=theme, name=name):
+                    if support.verbose >= 2:
+                        print('map', theme, name, default)
+                    newname = f'C.{name}'
+                    self.assertEqual(style.map(newname), {})
+                    style.map(newname, **default)
+                    self.assertEqual(style.map(newname), default)
+                    for key, value in default.items():
+                        self.assertEqual(style.map(newname, key), value)
+
+
 tests_gui = (StyleTest, )
 
 if __name__ == "__main__":