gh-128198: Add missing error checks for usages of PyIter_Next() (GH-128199)

Author: WolframAlph

Modules/_asynciomodule.c

@@ -3599,6 +3599,13 @@ _asyncio_all_tasks_impl(PyObject *module, PyObject *loop)
         Py_DECREF(item);
     }
     Py_DECREF(eager_iter);
+
+    if (PyErr_Occurred()) {
+        Py_DECREF(tasks);
+        Py_DECREF(loop);
+        return NULL;
+    }
+
     int err = 0;
     ASYNCIO_STATE_LOCK(state);
     struct llist_node *node;
@@ -3636,6 +3643,12 @@ _asyncio_all_tasks_impl(PyObject *module, PyObject *loop)
     }
     Py_DECREF(scheduled_iter);
     Py_DECREF(loop);
+
+    if (PyErr_Occurred()) {
+        Py_DECREF(tasks);
+        return NULL;
+    }
+
     return tasks;
 }
 

Objects/frameobject.c

@@ -264,6 +264,10 @@ framelocalsproxy_merge(PyObject* self, PyObject* other)
 
     Py_DECREF(iter);
 
+    if (PyErr_Occurred()) {
+        return -1;
+    }
+
     return 0;
 }
 

Objects/namespaceobject.c

@@ -141,6 +141,10 @@ namespace_repr(PyObject *ns)
             goto error;
     }
 
+    if (PyErr_Occurred()) {
+        goto error;
+    }
+
     separator = PyUnicode_FromString(", ");
     if (separator == NULL)
         goto error;