gh-109700: fix memory error handling in `PyDict_SetDefault` (#136338)

diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-07-06-14-53-19.gh-issue-109700.KVNQQi.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-06-14-53-19.gh-issue-109700.KVNQQi.rst
new file mode 100644 (file)
index 0000000..a37f4a5
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-07-06-14-53-19.gh-issue-109700.KVNQQi.rst
@@ -0,0 +1 @@
+Fix memory error handling in :c:func:`PyDict_SetDefault`.

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 6b7b150f0e2f2cb443acd34af6c4526bfb5e10e3..be62ae5eefd00dd11a3517b9972e158f7edcfc0c 100644 (file)
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -4411,6 +4411,7 @@ dict_setdefault_ref_lock_held(PyObject *d, PyObject *key, PyObject *default_valu
             if (result) {
                 *result = NULL;
             }
+            return -1;
         }
 
         STORE_USED(mp, mp->ma_used + 1);