Merge branch 'master' into revert-23107-revert-13893-fix-issue-37193revert-23107-revert-13893-fix-issue-37193

1 files changed, 16 insertions, 6 deletions

diff --git a/Objects/unionobject.c b/Objects/unionobject.c
index 1b7f8ab51a..32aa5078af 100644
--- a/Objects/unionobject.c
+++ b/Objects/unionobject.c
@@ -237,9 +237,19 @@ dedup_and_flatten_args(PyObject* args)
         PyObject* i_element = PyTuple_GET_ITEM(args, i);
         for (Py_ssize_t j = i + 1; j < arg_length; j++) {
             PyObject* j_element = PyTuple_GET_ITEM(args, j);
-            if (i_element == j_element) {
-                is_duplicate = 1;
+            int is_ga = PyObject_TypeCheck(i_element, &Py_GenericAliasType) &&
+                        PyObject_TypeCheck(j_element, &Py_GenericAliasType);
+            // RichCompare to also deduplicate GenericAlias types (slower)
+            is_duplicate = is_ga ? PyObject_RichCompareBool(i_element, j_element, Py_EQ)
+                : i_element == j_element;
+            // Should only happen if RichCompare fails
+            if (is_duplicate < 0) {
+                Py_DECREF(args);
+                Py_DECREF(new_args);
+                return NULL;
             }
+            if (is_duplicate)
+                break;
         }
         if (!is_duplicate) {
             Py_INCREF(i_element);
@@ -286,12 +296,12 @@ is_unionable(PyObject *obj)
         is_new_type(obj) ||
         is_special_form(obj) ||
         PyType_Check(obj) ||
-        type == &Py_GenericAliasType ||
+        PyObject_TypeCheck(obj, &Py_GenericAliasType) ||
         type == &_Py_UnionType);
 }
 
-static PyObject *
-type_or(PyTypeObject* self, PyObject* param)
+PyObject *
+_Py_union_type_or(PyObject* self, PyObject* param)
 {
     PyObject *tuple = PyTuple_Pack(2, self, param);
     if (tuple == NULL) {
@@ -404,7 +414,7 @@ static PyMethodDef union_methods[] = {
         {0}};
 
 static PyNumberMethods union_as_number = {
-        .nb_or = (binaryfunc)type_or, // Add __or__ function
+        .nb_or = _Py_union_type_or, // Add __or__ function
 };
 
 PyTypeObject _Py_UnionType = {