Sync pre-release CPython main branch from GitHub (2026-06-06)

Summary:
Imported python/cpython `3.16.0a0` from upstream rev [`ab93017`](https://www.github.com/python/cpython/commit/ab930175e7e909aaa3ec7e761bfdbb886677bebb) (committed 2026-06-06 21:38:15+00:00).

# Commit Info

- Base: (`3.16.0a0`) - [`785b6dc`](https://www.github.com/python/cpython/commit/785b6dcf71b08c34a1d0a1cff9dc4afe997ad283) (commit date: 2026-06-06 02:27:41+00:00)
- Imported: (`3.16.0a0`) - [`ab93017`](https://www.github.com/python/cpython/commit/ab930175e7e909aaa3ec7e761bfdbb886677bebb) (commit date: 2026-06-06 21:38:15+00:00)

# Noteworthy file changes

- Low-signal files (7 added) (NEWS.d, docs, .github)

Complete list of added/removed files: https://www.internalfb.com/intern/everpaste/?color=0&handle=GKwr5yLiVo9oNAAQAGJYMwUHxRYNbr0LAAAz

Differential Revision: D107786331

fbshipit-source-id: 55c4a150e52201baed8d4e3d7256de6d2f336e42

Author: generatedunixname1734921407115435

Doc/c-api/long.rst

@@ -71,6 +71,12 @@ distinguished from a number.  Use :c:func:`PyErr_Occurred` to disambiguate.
    on failure.
 
 
+.. c:function:: PyObject* PyLong_FromUnsignedLongLong(unsigned long long v)
+
+   Return a new :c:type:`PyLongObject` object from a C :c:expr:`unsigned long long`,
+   or ``NULL`` on failure.
+
+
 .. c:function:: PyObject* PyLong_FromInt32(int32_t value)
                 PyObject* PyLong_FromInt64(int64_t value)
 
@@ -81,12 +87,6 @@ distinguished from a number.  Use :c:func:`PyErr_Occurred` to disambiguate.
    .. versionadded:: 3.14
 
 
-.. c:function:: PyObject* PyLong_FromUnsignedLongLong(unsigned long long v)
-
-   Return a new :c:type:`PyLongObject` object from a C :c:expr:`unsigned long long`,
-   or ``NULL`` on failure.
-
-
 .. c:function:: PyObject* PyLong_FromUInt32(uint32_t value)
                 PyObject* PyLong_FromUInt64(uint64_t value)
 

Doc/library/importlib.resources.rst

@@ -240,7 +240,6 @@ For all the following functions:
 
     .. versionchanged:: 3.13
         Multiple *path_names* are accepted.
-        *encoding* and *errors* must be given as keyword arguments.
 
 
 .. function:: is_resource(anchor, *path_names)

Doc/library/logging.handlers.rst

@@ -402,7 +402,8 @@ timed intervals.
    rollover interval.
 
    When computing the next rollover time for the first time (when the handler
-   is created), the last modification time of an existing log file, or else
+   is created), the creation time (if supported by the OS and file system)
+   or the last modification of an existing log file, or else
    the current time, is used to compute when the next rotation will occur.
 
    If the *utc* argument is true, times in UTC will be used; otherwise
@@ -449,6 +450,10 @@ timed intervals.
    .. versionchanged:: 3.9
       The *errors* parameter was added.
 
+   .. versionchanged:: next
+      Use the creation time instead of the last modification time, if supported by the OS and file system.
+
+
    .. method:: doRollover()
 
       Does a rollover, as described above.

Doc/library/math.rst

@@ -83,13 +83,20 @@ noted otherwise, all return values are floats.
 
 **Trigonometric functions**
 --------------------------------------------------------------------------------------------------
-:func:`acos(x) <acos>`                                Arc cosine of *x*
-:func:`asin(x) <asin>`                                Arc sine of *x*
-:func:`atan(x) <atan>`                                Arc tangent of *x*
-:func:`atan2(y, x) <atan2>`                           ``atan(y / x)``
-:func:`cos(x) <cos>`                                  Cosine of *x*
-:func:`sin(x) <sin>`                                  Sine of *x*
-:func:`tan(x) <tan>`                                  Tangent of *x*
+:func:`acos(x) <acos>`                                Arc cosine of *x*, in radians
+:func:`acospi(x) <acospi>`                            Arc cosine of *x*, in half-turns
+:func:`asin(x) <asin>`                                Arc sine of *x*, in radians
+:func:`asinpi(x) <asinpi>`                            Arc sine of *x*, in half-turns
+:func:`atan(x) <atan>`                                Arc tangent of *x*, in radians
+:func:`atanpi(x) <atanpi>`                            Arc tangent of *x*, in half-turns
+:func:`atan2(y, x) <atan2>`                           ``atan(y / x)``, in radians
+:func:`atan2pi(y, x) <atan2pi>`                       ``atan(y / x)``, in half-turns
+:func:`cos(x) <cos>`                                  Cosine of *x* radians
+:func:`cospi(x) <cospi>`                              Cosine of *x⋅π* radians
+:func:`sin(x) <sin>`                                  Sine of *x* radians
+:func:`sinpi(x) <sinpi>`                              Sine of *x⋅π* radians
+:func:`tan(x) <tan>`                                  Tangent of *x* radians
+:func:`tanpi(x) <tanpi>`                              Tangent of *x⋅π* radians
 
 **Hyperbolic functions**
 --------------------------------------------------------------------------------------------------
@@ -599,18 +606,42 @@ Trigonometric functions
    ``pi``.
 
 
+.. function:: acospi(x)
+
+   Return the arc cosine of *x*, in half-turns. The result is between ``0`` and
+   ``1``.
+
+   .. versionadded:: next
+
+
 .. function:: asin(x)
 
    Return the arc sine of *x*, in radians. The result is between ``-pi/2`` and
    ``pi/2``.
 
 
+.. function:: asinpi(x)
+
+   Return the arc sine of *x*, in half-turns. The result is between ``-0.5`` and
+   ``0.5``.
+
+   .. versionadded:: next
+
+
 .. function:: atan(x)
 
    Return the arc tangent of *x*, in radians. The result is between ``-pi/2`` and
    ``pi/2``.
 
 
+.. function:: atanpi(x)
+
+   Return the arc tangent of *x*, in half-turns. The result is between ``-0.5`` and
+   ``0.5``.
+
+   .. versionadded:: next
+
+
 .. function:: atan2(y, x)
 
    Return ``atan(y / x)``, in radians. The result is between ``-pi`` and ``pi``.
@@ -621,21 +652,54 @@ Trigonometric functions
    -1)`` is ``-3*pi/4``.
 
 
+.. function:: atan2pi(y, x)
+
+   Return ``atanpi(y / x)``, in half-turns. The result is between ``-1`` and ``1``.
+   The vector in the plane from the origin to point ``(x, y)`` makes this angle
+   with the positive X axis. The point of :func:`atan2pi` is that the signs of both
+   inputs are known to it, so it can compute the correct quadrant for the angle.
+   For example, ``atanpi(1)`` and ``atan2pi(1, 1)`` are both ``0.25``, but
+   ``atan2pi(-1, -1)`` is ``-0.75``.
+
+   .. versionadded:: next
+
+
 .. function:: cos(x)
 
    Return the cosine of *x* radians.
 
 
+.. function:: cospi(x)
+
+   Return the cosine of *x* half-turns (*x⋅π* radians).
+
+   .. versionadded:: next
+
+
 .. function:: sin(x)
 
    Return the sine of *x* radians.
 
 
+.. function:: sinpi(x)
+
+   Return the sine of *x* half-turns (*x⋅π* radians).
+
+   .. versionadded:: next
+
+
 .. function:: tan(x)
 
    Return the tangent of *x* radians.
 
 
+.. function:: tanpi(x)
+
+   Return the tangent of *x* half-turns (*x⋅π* radians).
+
+   .. versionadded:: next
+
+
 Hyperbolic functions
 --------------------
 

Doc/whatsnew/3.16.rst

@@ -102,6 +102,28 @@ lzma
   requires ``lzma`` 5.4.0 or newer while RISC-V requires 5.6.0 or newer.
   (Contributed by Chien Wong in :gh:`115988`.)
 
+logging
+-------
+
+* :class:`~logging.handlers.TimedRotatingFileHandler` now uses the creation
+  time instead of the last modification time of an existing log file as
+  the basis for the first rotation after handler creation, if supported by
+  the OS and file system.
+  This allows it to be used in short-running programs that start and end
+  before the rotation interval expires.
+  (Contributed by Iván Márton and Serhiy Storchaka in :gh:`84649`.)
+
+math
+----
+
+* Added trigonometric functions that work in units of half turns, rather than
+  radians. The new functions :func:`math.acospi`, :func:`math.asinpi`,
+  :func:`math.atanpi`, and :func:`math.atan2pi` return half-turn angles. The
+  new functions :func:`math.cospi`, :func:`math.sinpi`, and :func:`math.tanpi`
+  take half-turn angle arguments. These functions are recommended by IEEE
+  754-2019 and standardized in C23.
+  (Contributed by Jeff Epler in :gh:`150534`.)
+
 os
 --
 

Lib/idlelib/iomenu.py

@@ -61,6 +61,7 @@ def set_filename_change_hook(self, hook):
         self.filename_change_hook = hook
 
     filename = None
+    file_timestamp = None
     dirname = None
 
     def set_filename(self, filename):
@@ -127,6 +128,7 @@ def loadfile(self, filename):
                     chars = f.read()
                     fileencoding = f.encoding
                     eol_convention = f.newlines
+                    file_timestamp = self.getmtime(filename)
                     converted = False
             except (UnicodeDecodeError, SyntaxError):
                 # Wait for the editor window to appear
@@ -142,6 +144,7 @@ def loadfile(self, filename):
                     chars = f.read()
                     fileencoding = f.encoding
                     eol_convention = f.newlines
+                    file_timestamp = self.getmtime(filename)
                     converted = True
         except OSError as err:
             messagebox.showerror("I/O Error", str(err), parent=self.text)
@@ -170,6 +173,7 @@ def loadfile(self, filename):
         self.text.insert("1.0", chars)
         self.reset_undo()
         self.set_filename(filename)
+        self.file_timestamp = file_timestamp
         if converted:
             # We need to save the conversion results first
             # before being able to execute the code
@@ -206,7 +210,26 @@ def save(self, event):
         if not self.filename:
             self.save_as(event)
         else:
+            # Check the time of most recent content modification so the
+            # user doesn't accidentally overwrite a newer version of the file.
+            try:
+                file_timestamp = self.getmtime(self.filename)
+            except OSError:
+                pass
+            else:
+                if self.file_timestamp != file_timestamp:
+                    confirm = messagebox.askokcancel(
+                        title="File has changed",
+                        message=(
+                            "The file has changed on disk since reading it!\n\n"
+                            "Do you really want to overwrite it?"),
+                        default=messagebox.CANCEL,
+                        parent=self.text)
+                    if not confirm:
+                        return "break"
+
             if self.writefile(self.filename):
+                self.file_timestamp = self.getmtime(self.filename)
                 self.set_saved(True)
                 try:
                     self.editwin.store_file_breaks()
@@ -219,6 +242,7 @@ def save_as(self, event):
         filename = self.asksavefile()
         if filename:
             if self.writefile(filename):
+                self.file_timestamp = self.getmtime(filename)
                 self.set_filename(filename)
                 self.set_saved(1)
                 try:
@@ -251,6 +275,9 @@ def writefile(self, filename):
                                    parent=self.text)
             return False
 
+    def getmtime(self, filename):
+        return os.stat(filename).st_mtime
+
     def fixnewlines(self):
         """Return text with os eols.
 

Lib/logging/handlers.py

@@ -284,14 +284,28 @@ def __init__(self, filename, when='h', interval=1, backupCount=0,
         if os.path.exists(filename):
             # Use the minimum of file creation and modification time as
             # the base of the rollover calculation
-            stat_result = os.stat(filename)
-            # Use st_birthtime whenever it is available or use st_ctime
-            # instead otherwise
-            try:
-                creation_time = stat_result.st_birthtime
-            except AttributeError:
-                creation_time = stat_result.st_ctime
-            t = int(min(creation_time, stat_result.st_mtime))
+            creation_time = modification_time = None
+            if hasattr(os, 'statx'):
+                statx_result = os.statx(filename,
+                        os.STATX_BTIME|os.STATX_CTIME|os.STATX_MTIME)
+                # Use stx_btime whenever it is available or use stx_ctime
+                # instead otherwise
+                creation_time = statx_result.stx_btime
+                if creation_time is None:
+                    creation_time = statx_result.stx_ctime
+                modification_time = statx_result.stx_mtime
+            if creation_time is None or modification_time is None:
+                stat_result = os.stat(filename)
+                # Use st_birthtime whenever it is available or use st_ctime
+                # instead otherwise
+                if creation_time is None:
+                    try:
+                        creation_time = stat_result.st_birthtime
+                    except AttributeError:
+                        creation_time = stat_result.st_ctime
+                if modification_time is None:
+                    modification_time = stat_result.st_mtime
+            t = int(min(creation_time, modification_time))
         else:
             t = int(time.time())
         self.rolloverAt = self.computeRollover(t)

Lib/shutil.py

@@ -944,8 +944,8 @@ def move(src, dst, copy_function=copy2):
     return real_dst
 
 def _destinsrc(src, dst):
-    src = os.path.abspath(src)
-    dst = os.path.abspath(dst)
+    src = os.path.realpath(src)
+    dst = os.path.realpath(dst)
     if not src.endswith(os.path.sep):
         src += os.path.sep
     if not dst.endswith(os.path.sep):