diff --git a/Doc/library/textwrap.rst b/Doc/library/textwrap.rst
index a58b460fef409c..3c96c0e9cc0a38 100644
--- a/Doc/library/textwrap.rst
+++ b/Doc/library/textwrap.rst
@@ -102,6 +102,10 @@ functions should be good enough; otherwise, you should use an instance of
           print(repr(s))          # prints '    hello\n      world\n    '
           print(repr(dedent(s)))  # prints 'hello\n  world\n'
 
+   .. versionchanged:: 3.14
+      The :func:`!dedent` function now correctly normalizes blank lines containing
+      only whitespace characters. Previously, the implementation only normalized
+      blank lines containing tabs and spaces.
 
 .. function:: indent(text, prefix, predicate=None)
 
diff --git a/Doc/requirements.txt b/Doc/requirements.txt
index 716772b7f28d99..d0107744ecbe85 100644
--- a/Doc/requirements.txt
+++ b/Doc/requirements.txt
@@ -7,7 +7,7 @@
 # won't suddenly cause build failures. Updating the version is fine as long
 # as no warnings are raised by doing so.
 # Keep this version in sync with ``Doc/conf.py``.
-sphinx~=9.0.0
+sphinx<9.0.0
 
 blurb
 
diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
index 9459b73bcb502f..c12a1920b10722 100644
--- a/Doc/whatsnew/3.14.rst
+++ b/Doc/whatsnew/3.14.rst
@@ -2265,6 +2265,15 @@ pdb
   (Contributed by Tian Gao in :gh:`124533`.)
 
 
+textwrap
+--------
+
+* Optimize the :func:`~textwrap.dedent` function, improving performance by
+  an average of 2.4x, with larger improvements for bigger inputs,
+  and fix a bug with incomplete normalization of blank lines with whitespace
+  characters other than space and tab.
+
+
 uuid
 ----
 
diff --git a/Lib/logging/handlers.py b/Lib/logging/handlers.py
index 2748b5941eade2..4a07258f8d6d07 100644
--- a/Lib/logging/handlers.py
+++ b/Lib/logging/handlers.py
@@ -196,7 +196,11 @@ def shouldRollover(self, record):
         if self.stream is None:                 # delay was set...
             self.stream = self._open()
         if self.maxBytes > 0:                   # are we rolling over?
-            pos = self.stream.tell()
+            try:
+                pos = self.stream.tell()
+            except io.UnsupportedOperation:
+                # gh-143237: Never rollover a named pipe.
+                return False
             if not pos:
                 # gh-116263: Never rollover an empty file
                 return False
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index 8815426fc99c39..848084e6e36878 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -25,6 +25,7 @@
 
 import codecs
 import configparser
+import contextlib
 import copy
 import datetime
 import pathlib
@@ -6369,6 +6370,32 @@ def test_should_not_rollover_non_file(self):
         self.assertFalse(rh.shouldRollover(self.next_rec()))
         rh.close()
 
+    @unittest.skipUnless(hasattr(os, "mkfifo"), 'requires os.mkfifo()')
+    def test_should_not_rollover_named_pipe(self):
+        # gh-143237 - test with non-seekable special file (named pipe)
+        filename = os_helper.TESTFN
+        self.addCleanup(os_helper.unlink, filename)
+        try:
+            os.mkfifo(filename)
+        except PermissionError as e:
+            self.skipTest('os.mkfifo(): %s' % e)
+
+        data = 'not read'
+        def other_side():
+            nonlocal data
+            with open(filename, 'rb') as f:
+                data = f.read()
+
+        thread = threading.Thread(target=other_side)
+        with threading_helper.start_threads([thread]):
+            rh = logging.handlers.RotatingFileHandler(
+                    filename, encoding="utf-8", maxBytes=1)
+            with contextlib.closing(rh):
+                m = self.next_rec()
+                self.assertFalse(rh.shouldRollover(m))
+                rh.emit(m)
+        self.assertEqual(data.decode(), m.msg + os.linesep)
+
     def test_should_rollover(self):
         with open(self.fn, 'wb') as f:
             f.write(b'\n')
diff --git a/Misc/NEWS.d/next/Library/2025-12-28-20-28-05.gh-issue-143237.q1ymuA.rst b/Misc/NEWS.d/next/Library/2025-12-28-20-28-05.gh-issue-143237.q1ymuA.rst
new file mode 100644
index 00000000000000..131bebcd984ac2
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-12-28-20-28-05.gh-issue-143237.q1ymuA.rst
@@ -0,0 +1 @@
+Fix support of named pipes in the rotating :mod:`logging` handlers.