gh-94352: shlex.split() no longer accepts None (#94353)

shlex.split(): Passing None for s argument now raises an exception,
rather than reading sys.stdin. The feature was deprecated in Python
3.9.

Doc/library/shlex.rst

@@ -36,9 +36,9 @@ The :mod:`shlex` module defines the following functions:
       instance, passing ``None`` for *s* will read the string to split from
       standard input.
 
-   .. deprecated:: 3.9
-      Passing ``None`` for *s* will raise an exception in future Python
-      versions.
+   .. versionchanged:: 3.12
+      Passing ``None`` for *s* argument now raises an exception, rather than
+      reading :data:`sys.stdin`.
 
 .. function:: join(split_command)
 

Doc/whatsnew/3.12.rst

@@ -324,6 +324,11 @@ Changes in the Python API
   to :term:`filesystem encoding and error handler`.
   Argument files should be encoded in UTF-8 instead of ANSI Codepage on Windows.
 
+* :func:`shlex.split`: Passing ``None`` for *s* argument now raises an
+  exception, rather than reading :data:`sys.stdin`. The feature was deprecated
+  in Python 3.9.
+  (Contributed by Victor Stinner in :gh:`94352`.)
+
 
 Build Changes
 =============

Lib/shlex.py

@@ -305,9 +305,7 @@ class shlex:
 def split(s, comments=False, posix=True):
     """Split the string *s* using shell-like syntax."""
     if s is None:
-        import warnings
-        warnings.warn("Passing None for 's' to shlex.split() is deprecated.",
-                      DeprecationWarning, stacklevel=2)
+        raise ValueError("s argument must not be None")
     lex = shlex(s, posix=posix)
     lex.whitespace_split = True
     if not comments:

Lib/test/test_shlex.py

@@ -162,9 +162,8 @@ class ShlexTest(unittest.TestCase):
             tok = lex.get_token()
         return ret
 
-    @mock.patch('sys.stdin', io.StringIO())
-    def testSplitNoneDeprecation(self):
-        with self.assertWarns(DeprecationWarning):
+    def testSplitNone(self):
+        with self.assertRaises(ValueError):
             shlex.split(None)
 
     def testSplitPosix(self):

Misc/NEWS.d/next/Library/2022-06-28-00-24-48.gh-issue-94352.JY1Ayt.rst

@@ -0,0 +1,3 @@
+:func:`shlex.split`: Passing ``None`` for *s* argument now raises an exception,
+rather than reading :data:`sys.stdin`. The feature was deprecated in Python
+3.9. Patch by Victor Stinner.