TechPenguineer · pull · May 23, 2025 · May 23, 2025 · May 23, 2025 · May 23, 2025
diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
@@ -1788,8 +1788,14 @@ expression support in the :mod:`re` module).
 
    Return centered in a string of length *width*. Padding is done using the
    specified *fillchar* (default is an ASCII space). The original string is
-   returned if *width* is less than or equal to ``len(s)``.
+   returned if *width* is less than or equal to ``len(s)``.  For example::
 
+      >>> 'Python'.center(10)
+      '  Python  '
+      >>> 'Python'.center(10, '-')
+      '--Python--'
+      >>> 'Python'.center(4)
+      'Python'
 
 
 .. method:: str.count(sub[, start[, end]])
@@ -1799,8 +1805,18 @@ expression support in the :mod:`re` module).
    interpreted as in slice notation.
 
    If *sub* is empty, returns the number of empty strings between characters
-   which is the length of the string plus one.
-
+   which is the length of the string plus one. For example::
+
+      >>> 'spam, spam, spam'.count('spam')
+      3
+      >>> 'spam, spam, spam'.count('spam', 5)
+      2
+      >>> 'spam, spam, spam'.count('spam', 5, 10)
+      1
+      >>> 'spam, spam, spam'.count('eggs')
+      0
+      >>> 'spam, spam, spam'.count('')
+      17
 
 .. method:: str.encode(encoding="utf-8", errors="strict")
 

diff --git a/Doc/using/windows.rst b/Doc/using/windows.rst
@@ -504,6 +504,14 @@ configuration option.
    installing and uninstalling.
 
 
+.. _Add-AppxPackage: https://learn.microsoft.com/powershell/module/appx/add-appxpackage
+
+.. _Remove-AppxPackage: https://learn.microsoft.com/powershell/module/appx/remove-appxpackage
+
+.. _Add-AppxProvisionedPackage: https://learn.microsoft.com/powershell/module/dism/add-appxprovisionedpackage
+
+.. _PackageManager: https://learn.microsoft.com/uwp/api/windows.management.deployment.packagemanager
+
 .. _pymanager-advancedinstall:
 
 Advanced Installation
@@ -559,31 +567,44 @@ downloaded MSIX can be installed by launching or using the commands below.
 
 .. code-block:: powershell
 
-   $> winget download 9NQ7512CXL7T -e --skip-license --accept-package-agreements --disable-interactivity
+   $> winget download 9NQ7512CXL7T -e --skip-license --accept-package-agreements --accept-source-agreements
 
 To programmatically install or uninstall an MSIX using only PowerShell, the
-`Add-AppxPackage <https://learn.microsoft.com/powershell/module/appx/add-appxpackage>`_
-and `Remove-AppxPackage <https://learn.microsoft.com/powershell/module/appx/remove-appxpackage>`_
-PowerShell cmdlets are recommended:
+`Add-AppxPackage`_ and `Remove-AppxPackage`_ PowerShell cmdlets are recommended:
 
 .. code-block:: powershell
 
    $> Add-AppxPackage C:\Downloads\python-manager-25.0.msix
    ...
    $> Get-AppxPackage PythonSoftwareFoundation.PythonManager | Remove-AppxPackage
 
-The native APIs for package management may be found on the Windows
-`PackageManager <https://learn.microsoft.com/uwp/api/windows.management.deployment.packagemanager>`_
-class. The :func:`!AddPackageAsync` method installs for the current user, or use
-:func:`!StagePackageAsync` followed by :func:`!ProvisionPackageForAllUsersAsync`
-to install the Python install manager for all users from the MSIX package. Users
-will still need to install their own copies of Python itself, as there is no way
-to trigger those installs without being a logged in user.
+The latest release can be downloaded and installed by Windows by passing the
+AppInstaller file to the Add-AppxPackage command. This installs using the MSIX
+on python.org, and is only recommended for cases where installing via the Store
+(interactively or using WinGet) is not possible.
+
+.. code-block:: powershell
+
+   $> Add-AppxPackage -AppInstallerFile https://www.python.org/ftp/python/pymanager/pymanager.appinstaller
+
+Other tools and APIs may also be used to provision an MSIX package for all users
+on a machine, but Python does not consider this a supported scenario. We suggest
+looking into the PowerShell `Add-AppxProvisionedPackage`_ cmdlet, the native
+Windows `PackageManager`_ class, or the documentation and support for your
+deployment tool.
+
+Regardless of the install method, users will still need to install their own
+copies of Python itself, as there is no way to trigger those installs without
+being a logged in user. When using the MSIX, the latest version of Python will
+be available for all users to install without network access.
 
 Note that the MSIX downloadable from the Store and from the Python website are
 subtly different and cannot be installed at the same time. Wherever possible,
-we suggest using the above commands to download the package from the Store to
-reduce the risk of setting up conflicting installs.
+we suggest using the above WinGet commands to download the package from the
+Store to reduce the risk of setting up conflicting installs. There are no
+licensing restrictions on the Python install manager that would prevent using
+the Store package in this way.
+
 
 .. _pymanager-admin-config:
 

diff --git a/Misc/NEWS.d/next/Build/2025-05-21-22-13-30.gh-issue-134486.yvdL6f.rst b/Misc/NEWS.d/next/Build/2025-05-21-22-13-30.gh-issue-134486.yvdL6f.rst
@@ -0,0 +1,3 @@
+The :mod:`ctypes` module now performs a more portable test for the
+definition of :manpage:`alloca(3)`, fixing a compilation failure on
+NetBSD.
diff --git a/Modules/_ctypes/callbacks.c b/Modules/_ctypes/callbacks.c
@@ -11,18 +11,9 @@
 #include "pycore_call.h"          // _PyObject_CallNoArgs()
 #include "pycore_runtime.h"       // _Py_ID()
 
-#ifdef MS_WIN32
-#  include <malloc.h>
-#endif
-
 #include <ffi.h>
 #include "ctypes.h"
 
-#ifdef HAVE_ALLOCA_H
-/* AIX needs alloca.h for alloca() */
-#include <alloca.h>
-#endif
-
 /**************************************************************/
 
 static int

diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
@@ -77,16 +77,8 @@ module _ctypes
 #include <mach-o/dyld.h>
 #endif
 
-#ifdef MS_WIN32
-#include <malloc.h>
-#endif
-
 #include <ffi.h>
 #include "ctypes.h"
-#ifdef HAVE_ALLOCA_H
-/* AIX needs alloca.h for alloca() */
-#include <alloca.h>
-#endif
 
 #ifdef _Py_MEMORY_SANITIZER
 #include <sanitizer/msan_interface.h>

diff --git a/Modules/_ctypes/ctypes.h b/Modules/_ctypes/ctypes.h
@@ -1,5 +1,17 @@
-#if defined (__SVR4) && defined (__sun)
+/* Get a definition of alloca(). */
+#if (defined (__SVR4) && defined (__sun)) || defined(HAVE_ALLOCA_H)
 #   include <alloca.h>
+#elif defined(MS_WIN32)
+#   include <malloc.h>
+#endif
+
+/* If the system does not define alloca(), we have to hope for a compiler builtin. */
+#ifndef alloca
+#   if defined __GNUC__ || (__clang_major__ >= 4)
+#      define alloca __builtin_alloca
+#   else
+#     error "Could not define alloca() on your platform."
+#   endif
 #endif
 
 #include <stdbool.h>

diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
@@ -558,6 +558,7 @@ const uint16_t op_without_push[MAX_UOP_ID + 1] = {
 const bool op_skip[MAX_UOP_ID + 1] = {
     [_NOP] = true,
     [_CHECK_VALIDITY] = true,
+    [_CHECK_PERIODIC] = true,
     [_SET_IP] = true,
 };
 
@@ -617,7 +618,7 @@ remove_unneeded_uops(_PyUOpInstruction *buffer, int buffer_size)
                     while (op_skip[last->opcode]) {
                         last--;
                     }
-                    if (op_without_push[last->opcode]) {
+                    if (op_without_push[last->opcode] && op_without_pop[opcode]) {
                         last->opcode = op_without_push[last->opcode];
                         opcode = buffer[pc].opcode = op_without_pop[opcode];
                         if (op_without_pop[last->opcode]) {