Merge remote-tracking branch 'upstream/main' into tkinter-photoimage-tk9-options

# Conflicts:
#	Doc/whatsnew/3.16.rst

Author: serhiy-storchaka

Doc/library/tkinter.rst

@@ -6076,6 +6076,14 @@ Image classes
       it is displayed as transparent and the background of whatever window it
       is displayed in shows through.
 
+   .. method:: redither()
+
+      Recalculate the dithered image in each window where it is displayed.
+      This is useful when the image data was supplied in pieces, in which case
+      the dithered image may not be exactly correct.
+
+      .. versionadded:: next
+
    .. method:: cget(option)
 
       Return the current value of the configuration option *option*.

Doc/whatsnew/3.16.rst

@@ -201,6 +201,10 @@ tkinter
   the *withalpha* parameter of :meth:`~tkinter.PhotoImage.get`.
   (Contributed by Serhiy Storchaka in :gh:`151890`.)
 
+* Added the :meth:`~tkinter.PhotoImage.redither` method which recalculates the
+  dithered image when its data was supplied in pieces.
+  (Contributed by Serhiy Storchaka in :gh:`151888`.)
+
 
 xml
 ---

Lib/sysconfig/__init__.py

@@ -182,6 +182,8 @@ def joinuser(*args):
 _CONFIG_VARS = None
 # True iff _CONFIG_VARS has been fully initialized.
 _CONFIG_VARS_INITIALIZED = False
+_config_vars_cached_prefix = None
+_config_vars_cached_exec_prefix = None
 _USER_BASE = None
 
 
@@ -600,16 +602,20 @@ def get_config_vars(*args):
     each argument in the configuration variable dictionary.
     """
     global _CONFIG_VARS_INITIALIZED
+    global _config_vars_cached_prefix
+    global _config_vars_cached_exec_prefix
 
     # Avoid claiming the lock once initialization is complete.
+    prefix = os.path.normpath(sys.prefix)
+    exec_prefix = os.path.normpath(sys.exec_prefix)
     if _CONFIG_VARS_INITIALIZED:
         # GH-126789: If sys.prefix or sys.exec_prefix were updated, invalidate the cache.
-        prefix = os.path.normpath(sys.prefix)
-        exec_prefix = os.path.normpath(sys.exec_prefix)
-        if _CONFIG_VARS['prefix'] != prefix or _CONFIG_VARS['exec_prefix'] != exec_prefix:
+        if _config_vars_cached_prefix != prefix or _config_vars_cached_exec_prefix != exec_prefix:
             with _CONFIG_VARS_LOCK:
                 _CONFIG_VARS_INITIALIZED = False
                 _init_config_vars()
+                _config_vars_cached_prefix = prefix
+                _config_vars_cached_exec_prefix = exec_prefix
     else:
         # Initialize the config_vars cache.
         with _CONFIG_VARS_LOCK:
@@ -619,6 +625,8 @@ def get_config_vars(*args):
             # don't re-enter init_config_vars().
             if _CONFIG_VARS is None:
                 _init_config_vars()
+            _config_vars_cached_prefix = prefix
+            _config_vars_cached_exec_prefix = exec_prefix
 
     if args:
         vals = []

Lib/test/test_tkinter/test_images.py

@@ -311,6 +311,12 @@ def test_blank(self):
         self.assertEqual(image.height(), 16)
         self.assertEqual(image.get(4, 6), self.colorlist(0, 0, 0))
 
+    def test_redither(self):
+        image = self.create()
+        pixel = image.get(4, 6)
+        image.redither()  # Recalculates the dithering; the data is unchanged.
+        self.assertEqual(image.get(4, 6), pixel)
+
     def test_copy(self):
         image = self.create()
         image2 = image.copy()

Lib/test/test_venv.py

@@ -773,6 +773,46 @@ def test_special_chars_csh(self):
         self.assertTrue(env_name.encode() in lines[0])
         self.assertEndsWith(lines[1], env_name.encode())
 
+    # gh-140006: the fish prompt override must keep working when a user
+    # function shadows a builtin it relies on.
+    @unittest.skipIf(os.name == 'nt', 'fish is not available on Windows')
+    def test_fish_activate_shadowed_builtins(self):
+        """
+        The fish prompt override restores the exit status through `source` and
+        prints through `printf`/`echo`/`set_color`.  A user function that
+        shadows one of those builtins (a common pattern for `.`-style directory
+        navigators) must not hijack the prompt or break status restoration.
+        """
+        fish = shutil.which('fish')
+        if fish is None:
+            self.skipTest('fish required for this test')
+        rmtree(self.env_dir)
+        builder = venv.EnvBuilder(clear=True)
+        builder.create(self.env_dir)
+        activate = os.path.join(self.env_dir, self.bindir, 'activate.fish')
+        test_script = os.path.join(self.env_dir, 'test_shadowed_builtins.fish')
+        with open(test_script, "w") as f:
+            f.write(
+                # The pre-existing prompt reports the status it receives;
+                # activation copies it to _old_fish_prompt.
+                'function fish_prompt; builtin echo "OLDSTATUS=$status"; end\n'
+                f'source {shlex.quote(activate)}\n'
+                # Shadow every builtin the override uses.  A dot-navigator that
+                # lists the directory is the reported failure.
+                'function .; builtin echo DOT_LEAK; end\n'
+                'function source; builtin echo SOURCE_LEAK; end\n'
+                'function echo; command echo ECHO_LEAK; end\n'
+                'function printf; command printf PRINTF_LEAK; end\n'
+                'function set_color; command true; end\n'
+                'function _exit7; return 7; end\n'
+                '_exit7\n'
+                'fish_prompt\n'
+            )
+        out, err = check_output([fish, '--no-config', test_script])
+        text = out.decode()
+        self.assertNotIn('LEAK', text)
+        self.assertIn('OLDSTATUS=7', text)
+
     # gh-124651: test quoted strings on Windows
     @unittest.skipUnless(os.name == 'nt', 'only relevant on Windows')
     def test_special_chars_windows(self):

Lib/tkinter/__init__.py

@@ -4571,6 +4571,13 @@ def blank(self):
         """Display a transparent image."""
         self.tk.call(self.name, 'blank')
 
+    def redither(self):
+        """Recalculate the dithered image in each window where it is displayed.
+
+        Useful when the image data was supplied in pieces, in which case the
+        dithered image may not be exactly correct."""
+        self.tk.call(self.name, 'redither')
+
     def cget(self, option):
         """Return the value of OPTION."""
         return self.tk.call(self.name, 'cget', '-' + option)

Lib/venv/scripts/common/activate.fish

@@ -15,18 +15,18 @@ function deactivate  -d "Exit virtual environment and return to normal shell env
     if test -n "$_OLD_FISH_PROMPT_OVERRIDE"
         set -e _OLD_FISH_PROMPT_OVERRIDE
         # prevents error when using nested fish instances (Issue #93858)
-        if functions -q _old_fish_prompt
-            functions -e fish_prompt
-            functions -c _old_fish_prompt fish_prompt
-            functions -e _old_fish_prompt
+        if builtin functions -q _old_fish_prompt
+            builtin functions -e fish_prompt
+            builtin functions -c _old_fish_prompt fish_prompt
+            builtin functions -e _old_fish_prompt
         end
     end
 
     set -e VIRTUAL_ENV
     set -e VIRTUAL_ENV_PROMPT
     if test "$argv[1]" != "nondestructive"
         # Self-destruct!
-        functions -e deactivate
+        builtin functions -e deactivate
     end
 end
 
@@ -52,18 +52,21 @@ if test -z "$VIRTUAL_ENV_DISABLE_PROMPT"
     # fish uses a function instead of an env var to generate the prompt.
 
     # Save the current fish_prompt function as the function _old_fish_prompt.
-    functions -c fish_prompt _old_fish_prompt
+    builtin functions -c fish_prompt _old_fish_prompt
 
     # With the original prompt function renamed, we can override with our own.
+    # Call every builtin through `builtin` so a user function that shadows
+    # `printf`, `set_color`, `echo`, or `source`/`.` cannot hijack the prompt
+    # (Issue #140006).
     function fish_prompt
         # Save the return status of the last command.
         set -l old_status $status
 
         # Output the venv prompt; color taken from the blue of the Python logo.
-        printf "%s(%s)%s " (set_color 4B8BBE) __VENV_PROMPT__ (set_color normal)
+        builtin printf "%s(%s)%s " (builtin set_color 4B8BBE) __VENV_PROMPT__ (builtin set_color normal)
 
         # Restore the return status of the previous command.
-        echo "exit $old_status" | .
+        builtin echo "exit $old_status" | builtin source -
         # Output the original/"old" prompt.
         _old_fish_prompt
     end

Misc/NEWS.d/next/Library/2026-06-04-19-24-13.gh-issue-140006.TD8HKl.rst

@@ -0,0 +1,4 @@
+The :mod:`venv` ``activate.fish`` script now calls fish builtins through
+``builtin`` so a user function that shadows ``.``/``source``, ``echo``,
+``printf``, ``set_color``, or ``functions`` can no longer hijack the virtual
+environment prompt or break exit-status reporting.

Misc/NEWS.d/next/Library/2026-06-22-01-57-55.gh-issue-151888.hO7mxi.rst

@@ -0,0 +1,2 @@
+Add the :meth:`!tkinter.PhotoImage.redither` method, wrapping the photo image
+``redither`` Tk command.