Merge branch '3.14' of https://github.com/python/cpython into 3.14

Author: hugovk

Doc/c-api/weakref.rst

@@ -42,8 +42,8 @@ as much as it can.
    callable object that receives notification when *ob* is garbage collected; it
    should accept a single parameter, which will be the weak reference object
    itself. *callback* may also be ``None`` or ``NULL``.  If *ob* is not a
-   weakly referenceable object, or if *callback* is not callable, ``None``, or
-   ``NULL``, this will return ``NULL`` and raise :exc:`TypeError`.
+   weakly referenceable object, this will raise :exc:`TypeError` and return
+   ``NULL``.
 
    .. seealso::
       :c:func:`PyType_SUPPORTS_WEAKREFS` for checking if *ob* is weakly
@@ -58,8 +58,8 @@ as much as it can.
    be a callable object that receives notification when *ob* is garbage
    collected; it should accept a single parameter, which will be the weak
    reference object itself. *callback* may also be ``None`` or ``NULL``.  If *ob*
-   is not a weakly referenceable object, or if *callback* is not callable,
-   ``None``, or ``NULL``, this will return ``NULL`` and raise :exc:`TypeError`.
+   weakly referenceable object, this will raise :exc:`TypeError` and return
+   ``NULL``.
 
    .. seealso::
       :c:func:`PyType_SUPPORTS_WEAKREFS` for checking if *ob* is weakly

Lib/test/test_exceptions.py

@@ -1706,6 +1706,20 @@ def inner():
         gc_collect()  # For PyPy or other GCs.
         self.assertEqual(wr(), None)
 
+    def test_oserror_reinit_leak(self):
+        # gh-150988: Check for memory leak when re-initializing OSError.
+        # Previously, setting OSError attributes in a subclass
+        # before calling super().__init__() leaked memory.
+        class LeakingOSError(OSError):
+            def __init__(self, code, message, filename, filename2):
+                self.strerror = message
+                self.filename = filename
+                self.filename2 = filename2
+                super().__init__(code, message, filename, None, filename2)
+
+        exc = LeakingOSError(1, "some message", "filename.py", "filename2.py")
+        exc.__init__(2, "another message", "filename3.py", "filename4.py")
+
     def test_errno_ENOTDIR(self):
         # Issue #12802: "not a directory" errors are ENOTDIR even on Windows
         with self.assertRaises(OSError) as cm:

Misc/NEWS.d/next/Core_and_Builtins/2026-06-05-22-52-41.gh-issue-150988.fDKfMJ.rst

@@ -0,0 +1,2 @@
+Fix a reference leak in :exc:`OSError` when attributes are set before
+``super().__init__()``.

Objects/exceptions.c

@@ -2074,10 +2074,10 @@ oserror_init(PyOSErrorObject *self, PyObject **p_args,
                 return -1;
         }
         else {
-            self->filename = Py_NewRef(filename);
+            Py_XSETREF(self->filename, Py_NewRef(filename));
 
             if (filename2 && filename2 != Py_None) {
-                self->filename2 = Py_NewRef(filename2);
+                Py_XSETREF(self->filename2, Py_NewRef(filename2));
             }
 
             if (nargs >= 2 && nargs <= 5) {
@@ -2092,10 +2092,10 @@ oserror_init(PyOSErrorObject *self, PyObject **p_args,
             }
         }
     }
-    self->myerrno = Py_XNewRef(myerrno);
-    self->strerror = Py_XNewRef(strerror);
+    Py_XSETREF(self->myerrno, Py_XNewRef(myerrno));
+    Py_XSETREF(self->strerror, Py_XNewRef(strerror));
 #ifdef MS_WINDOWS
-    self->winerror = Py_XNewRef(winerror);
+    Py_XSETREF(self->winerror, Py_XNewRef(winerror));
 #endif
 
     /* Steals the reference to args */