[pull] main from python:main

Doc/c-api/conversion.rst

@@ -41,7 +41,7 @@ The return value (*rv*) for these functions should be interpreted as follows:
   ``rv + 1`` bytes would have been needed to succeed. ``str[size-1]`` is ``'\0'``
   in this case.
 
-* When ``rv < 0``, "something bad happened." ``str[size-1]`` is ``'\0'`` in
+* When ``rv < 0``, the output conversion failed and ``str[size-1]`` is ``'\0'`` in
   this case too, but the rest of *str* is undefined. The exact cause of the error
   depends on the underlying platform.
 

Doc/c-api/typeobj.rst

@@ -1260,7 +1260,7 @@ and :c:data:`PyType_Type` effectively act as defaults.)
       This bit indicates that instances of the class have a :attr:`~object.__dict__`
       attribute, and that the space for the dictionary is managed by the VM.
 
-      If this flag is set, :c:macro:`Py_TPFLAGS_HAVE_GC` should also be set.
+      If this flag is set, :c:macro:`Py_TPFLAGS_HAVE_GC` must also be set.
 
       The type traverse function must call :c:func:`PyObject_VisitManagedDict`
       and its clear function must call :c:func:`PyObject_ClearManagedDict`.
@@ -1278,6 +1278,8 @@ and :c:data:`PyType_Type` effectively act as defaults.)
       This bit indicates that instances of the class should be weakly
       referenceable.
 
+      If this flag is set, :c:macro:`Py_TPFLAGS_HAVE_GC` must also be set.
+
       .. versionadded:: 3.12
 
       **Inheritance:**

Doc/extending/newtypes.rst

@@ -560,6 +560,8 @@ For an object to be weakly referenceable, the extension type must set the
 field. The legacy :c:member:`~PyTypeObject.tp_weaklistoffset` field should
 be left as zero.
 
+If this flag is set, :c:macro:`Py_TPFLAGS_HAVE_GC` should also be set.
+
 Concretely, here is how the statically declared type object would look::
 
    static PyTypeObject TrivialType = {

Doc/whatsnew/3.15.rst

@@ -951,6 +951,14 @@ New features
   (Contributed by Victor Stinner in :gh:`111489`.)
 
 
+Changed C APIs
+--------------
+
+* If the :c:macro:`Py_TPFLAGS_MANAGED_DICT` or :c:macro:`Py_TPFLAGS_MANAGED_WEAKREF`
+  flag is set then :c:macro:`Py_TPFLAGS_HAVE_GC` must be set too.
+  (Contributed by Sergey Miryanov in :gh:`134786`)
+
+
 Porting to Python 3.15
 ----------------------
 

Include/object.h

@@ -529,7 +529,7 @@ given type object has a specified feature.
 #define Py_TPFLAGS_INLINE_VALUES (1 << 2)
 
 /* Placement of weakref pointers are managed by the VM, not by the type.
- * The VM will automatically set tp_weaklistoffset.
+ * The VM will automatically set tp_weaklistoffset. Implies Py_TPFLAGS_HAVE_GC.
  */
 #define Py_TPFLAGS_MANAGED_WEAKREF (1 << 3)
 

Lib/email/contentmanager.py

@@ -2,6 +2,7 @@
 import email.charset
 import email.message
 import email.errors
+import sys
 from email import quoprimime
 
 class ContentManager:
@@ -142,22 +143,23 @@ def _encode_base64(data, max_line_length):
 
 
 def _encode_text(string, charset, cte, policy):
+    # If max_line_length is 0 or None, there is no limit.
+    maxlen = policy.max_line_length or sys.maxsize
     lines = string.encode(charset).splitlines()
     linesep = policy.linesep.encode('ascii')
     def embedded_body(lines): return linesep.join(lines) + linesep
     def normal_body(lines): return b'\n'.join(lines) + b'\n'
     if cte is None:
         # Use heuristics to decide on the "best" encoding.
-        if max((len(x) for x in lines), default=0) <= policy.max_line_length:
+        if max(map(len, lines), default=0) <= maxlen:
             try:
                 return '7bit', normal_body(lines).decode('ascii')
             except UnicodeDecodeError:
                 pass
             if policy.cte_type == '8bit':
                 return '8bit', normal_body(lines).decode('ascii', 'surrogateescape')
         sniff = embedded_body(lines[:10])
-        sniff_qp = quoprimime.body_encode(sniff.decode('latin-1'),
-                                          policy.max_line_length)
+        sniff_qp = quoprimime.body_encode(sniff.decode('latin-1'), maxlen)
         sniff_base64 = binascii.b2a_base64(sniff)
         # This is a little unfair to qp; it includes lineseps, base64 doesn't.
         if len(sniff_qp) > len(sniff_base64):
@@ -172,9 +174,9 @@ def normal_body(lines): return b'\n'.join(lines) + b'\n'
         data = normal_body(lines).decode('ascii', 'surrogateescape')
     elif cte == 'quoted-printable':
         data = quoprimime.body_encode(normal_body(lines).decode('latin-1'),
-                                      policy.max_line_length)
+                                      maxlen)
     elif cte == 'base64':
-        data = _encode_base64(embedded_body(lines), policy.max_line_length)
+        data = _encode_base64(embedded_body(lines), maxlen)
     else:
         raise ValueError("Unknown content transfer encoding {}".format(cte))
     return cte, data

Lib/test/test_capi/test_type.py

@@ -274,3 +274,10 @@ def test_extension_managed_dict_type(self):
         obj.__dict__ = {'bar': 3}
         self.assertEqual(obj.__dict__, {'bar': 3})
         self.assertEqual(obj.bar, 3)
+
+    def test_extension_managed_weakref_nogc_type(self):
+        msg = ("type _testcapi.ManagedWeakrefNoGCType "
+               "has the Py_TPFLAGS_MANAGED_WEAKREF "
+               "flag but not Py_TPFLAGS_HAVE_GC flag")
+        with self.assertRaisesRegex(SystemError, msg):
+            _testcapi.create_managed_weakref_nogc_type()

Lib/test/test_email/test_message.py

@@ -1004,6 +1004,32 @@ def test_folding_with_long_nospace_http_policy_1(self):
         parsed_msg = message_from_bytes(m.as_bytes(), policy=policy.default)
         self.assertEqual(parsed_msg['Message-ID'], m['Message-ID'])
 
+    def test_no_wrapping_max_line_length(self):
+        # Test that falsey 'max_line_length' are converted to sys.maxsize.
+        for n in [0, None]:
+            with self.subTest(max_line_length=n):
+                self.do_test_no_wrapping_max_line_length(n)
+
+    def do_test_no_wrapping_max_line_length(self, falsey):
+        self.assertFalse(falsey)
+        pol = policy.default.clone(max_line_length=falsey)
+        subj = "S" * 100
+        body = "B" * 100
+        msg = EmailMessage(policy=pol)
+        msg["From"] = "[email protected]"
+        msg["To"] = "[email protected]"
+        msg["Subject"] = subj
+        msg.set_content(body)
+
+        raw = msg.as_bytes()
+        self.assertNotIn(b"=\n", raw,
+                         "Found fold indicator; wrapping not disabled")
+
+        parsed = message_from_bytes(raw, policy=policy.default)
+        self.assertEqual(parsed["Subject"], subj)
+        parsed_body = parsed.get_body().get_content().rstrip('\n')
+        self.assertEqual(parsed_body, body)
+
     def test_invalid_header_names(self):
         invalid_headers = [
             ('Invalid Header', 'contains space'),

Misc/NEWS.d/next/Core_and_Builtins/2025-06-24-13-12-58.gh-issue-134786.MF0VVk.rst

@@ -0,0 +1,2 @@
+If :c:macro:`Py_TPFLAGS_MANAGED_DICT` and :c:macro:`Py_TPFLAGS_MANAGED_WEAKREF`
+are used, then :c:macro:`Py_TPFLAGS_HAVE_GC` must be used as well.

Misc/NEWS.d/next/Library/2025-06-10-18-02-29.gh-issue-135307.fXGrcK.rst

@@ -0,0 +1,2 @@
+:mod:`email`: Fix exception in ``set_content()`` when encoding text
+and max_line_length is set to ``0`` or ``None`` (unlimited).

Modules/_testcapimodule.c

@@ -2562,6 +2562,39 @@ toggle_reftrace_printer(PyObject *ob, PyObject *arg)
     Py_RETURN_NONE;
 }
 
+
+typedef struct {
+    PyObject_HEAD
+} ManagedWeakrefNoGCObject;
+
+static void
+ManagedWeakrefNoGC_dealloc(PyObject *self)
+{
+    PyObject_ClearWeakRefs(self);
+    PyTypeObject *tp = Py_TYPE(self);
+    tp->tp_free(self);
+    Py_DECREF(tp);
+}
+
+static PyType_Slot ManagedWeakrefNoGC_slots[] = {
+    {Py_tp_dealloc, ManagedWeakrefNoGC_dealloc},
+    {0, 0}
+};
+
+static PyType_Spec ManagedWeakrefNoGC_spec = {
+    .name = "_testcapi.ManagedWeakrefNoGCType",
+    .basicsize = sizeof(ManagedWeakrefNoGCObject),
+    .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_MANAGED_WEAKREF),
+    .slots = ManagedWeakrefNoGC_slots,
+};
+
+static PyObject *
+create_managed_weakref_nogc_type(PyObject *self, PyObject *Py_UNUSED(args))
+{
+    return PyType_FromSpec(&ManagedWeakrefNoGC_spec);
+}
+
+
 static PyMethodDef TestMethods[] = {
     {"set_errno",               set_errno,                       METH_VARARGS},
     {"test_config",             test_config,                     METH_NOARGS},
@@ -2656,6 +2689,8 @@ static PyMethodDef TestMethods[] = {
     {"test_atexit", test_atexit, METH_NOARGS},
     {"code_offset_to_line", _PyCFunction_CAST(code_offset_to_line), METH_FASTCALL},
     {"toggle_reftrace_printer", toggle_reftrace_printer, METH_O},
+    {"create_managed_weakref_nogc_type",
+        create_managed_weakref_nogc_type, METH_NOARGS},
     {NULL, NULL} /* sentinel */
 };
 

Objects/typeobject.c

@@ -8898,6 +8898,13 @@ type_ready_preheader(PyTypeObject *type)
                         type->tp_name);
             return -1;
         }
+        if (!(type->tp_flags & Py_TPFLAGS_HAVE_GC)) {
+            PyErr_Format(PyExc_SystemError,
+                        "type %s has the Py_TPFLAGS_MANAGED_DICT flag "
+                        "but not Py_TPFLAGS_HAVE_GC flag",
+                        type->tp_name);
+            return -1;
+        }
         type->tp_dictoffset = -1;
     }
     if (type->tp_flags & Py_TPFLAGS_MANAGED_WEAKREF) {
@@ -8910,6 +8917,13 @@ type_ready_preheader(PyTypeObject *type)
                         type->tp_name);
             return -1;
         }
+        if (!(type->tp_flags & Py_TPFLAGS_HAVE_GC)) {
+            PyErr_Format(PyExc_SystemError,
+                        "type %s has the Py_TPFLAGS_MANAGED_WEAKREF flag "
+                        "but not Py_TPFLAGS_HAVE_GC flag",
+                        type->tp_name);
+            return -1;
+        }
         type->tp_weaklistoffset = MANAGED_WEAKREF_OFFSET;
     }
     return 0;