[3.14] gh-138804: Check type in shlex.quote (GH-138809) (#138846)

Co-authored-by: Christoph Walcher <[email protected]>

Author: miss-islington

Lib/shlex.py

@@ -322,6 +322,9 @@ def quote(s):
     if not s:
         return "''"
 
+    if not isinstance(s, str):
+        raise TypeError(f"expected string object, got {type(s).__name__!r}")
+
     # Use bytes.translate() for performance
     safe_chars = (b'%+,-./0123456789:=@'
                   b'ABCDEFGHIJKLMNOPQRSTUVWXYZ_'

Lib/test/test_shlex.py

@@ -330,6 +330,7 @@ def testQuote(self):
         unsafe = '"`$\\!' + unicode_sample
 
         self.assertEqual(shlex.quote(''), "''")
+        self.assertEqual(shlex.quote(None), "''")
         self.assertEqual(shlex.quote(safeunquoted), safeunquoted)
         self.assertEqual(shlex.quote('test file name'), "'test file name'")
         for u in unsafe:
@@ -338,6 +339,8 @@ def testQuote(self):
         for u in unsafe:
             self.assertEqual(shlex.quote("test%s'name'" % u),
                              "'test%s'\"'\"'name'\"'\"''" % u)
+        self.assertRaises(TypeError, shlex.quote, 42)
+        self.assertRaises(TypeError, shlex.quote, b"abc")
 
     def testJoin(self):
         for split_command, command in [

Misc/NEWS.d/next/Library/2025-09-12-01-01-05.gh-issue-138804.46ZukT.rst

@@ -0,0 +1,3 @@
+Raise :exc:`TypeError` instead of :exc:`AttributeError` when an argument of
+incorrect type is passed to :func:`shlex.quote`. This restores the behavior of
+the function prior to 3.14.