Merge branch '3.13' of https://github.com/python/cpython into 3.13

Author: Yhg1s

Doc/c-api/memory.rst

@@ -81,7 +81,7 @@ memory footprint as a whole. Consequently, under certain circumstances, the
 Python memory manager may or may not trigger appropriate actions, like garbage
 collection, memory compaction or other preventive procedures. Note that by using
 the C library allocator as shown in the previous example, the allocated memory
-for the I/O buffer escapes completely the Python memory manager.
+for the I/O buffer completely escapes the Python memory manager.
 
 .. seealso::
 
@@ -161,7 +161,7 @@ zero bytes.
 
 .. c:function:: void* PyMem_RawCalloc(size_t nelem, size_t elsize)
 
-   Allocates *nelem* elements each whose size in bytes is *elsize* and returns
+   Allocates *nelem* elements each of size *elsize* bytes and returns
    a pointer of type :c:expr:`void*` to the allocated memory, or ``NULL`` if the
    request fails. The memory is initialized to zeros.
 
@@ -232,7 +232,7 @@ The :ref:`default memory allocator <default-memory-allocators>` uses the
 
 .. c:function:: void* PyMem_Calloc(size_t nelem, size_t elsize)
 
-   Allocates *nelem* elements each whose size in bytes is *elsize* and returns
+   Allocates *nelem* elements each of size *elsize* bytes and returns
    a pointer of type :c:expr:`void*` to the allocated memory, or ``NULL`` if the
    request fails. The memory is initialized to zeros.
 
@@ -364,7 +364,7 @@ The :ref:`default object allocator <default-memory-allocators>` uses the
 
 .. c:function:: void* PyObject_Calloc(size_t nelem, size_t elsize)
 
-   Allocates *nelem* elements each whose size in bytes is *elsize* and returns
+   Allocates *nelem* elements each of size *elsize* bytes and returns
    a pointer of type :c:expr:`void*` to the allocated memory, or ``NULL`` if the
    request fails. The memory is initialized to zeros.
 

Lib/test/test_exceptions.py

@@ -1662,6 +1662,20 @@ 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

@@ -1846,10 +1846,10 @@ 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) {
@@ -1864,10 +1864,10 @@ 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 */