1 files changed, 29 insertions, 9 deletions

diff --git a/Objects/object.c b/Objects/object.c
index 1223983753a..3ed7d55593d 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -1213,16 +1213,27 @@ PyObject_HasAttrString(PyObject *obj, const char *name)
 int
 PyObject_SetAttrString(PyObject *v, const char *name, PyObject *w)
 {
-    PyObject *s;
-    int res;
+    PyThreadState *tstate = _PyThreadState_GET();
+    if (w == NULL && _PyErr_Occurred(tstate)) {
+        PyObject *exc = _PyErr_GetRaisedException(tstate);
+        _PyErr_SetString(tstate, PyExc_SystemError,
+            "PyObject_SetAttrString() must not be called with NULL value "
+            "and an exception set");
+        _PyErr_ChainExceptions1Tstate(tstate, exc);
+        return -1;
+    }
 
-    if (Py_TYPE(v)->tp_setattr != NULL)
+    if (Py_TYPE(v)->tp_setattr != NULL) {
         return (*Py_TYPE(v)->tp_setattr)(v, (char*)name, w);
-    s = PyUnicode_InternFromString(name);
-    if (s == NULL)
+    }
+
+    PyObject *s = PyUnicode_InternFromString(name);
+    if (s == NULL) {
         return -1;
-    res = PyObject_SetAttr(v, s, w);
-    Py_XDECREF(s);
+    }
+
+    int res = PyObject_SetAttr(v, s, w);
+    Py_DECREF(s);
     return res;
 }
 
@@ -1440,6 +1451,16 @@ PyObject_HasAttr(PyObject *obj, PyObject *name)
 int
 PyObject_SetAttr(PyObject *v, PyObject *name, PyObject *value)
 {
+    PyThreadState *tstate = _PyThreadState_GET();
+    if (value == NULL && _PyErr_Occurred(tstate)) {
+        PyObject *exc = _PyErr_GetRaisedException(tstate);
+        _PyErr_SetString(tstate, PyExc_SystemError,
+            "PyObject_SetAttr() must not be called with NULL value "
+            "and an exception set");
+        _PyErr_ChainExceptions1Tstate(tstate, exc);
+        return -1;
+    }
+
     PyTypeObject *tp = Py_TYPE(v);
     int err;
 
@@ -1451,8 +1472,7 @@ PyObject_SetAttr(PyObject *v, PyObject *name, PyObject *value)
     }
     Py_INCREF(name);
 
-    PyInterpreterState *interp = _PyInterpreterState_GET();
-    _PyUnicode_InternMortal(interp, &name);
+    _PyUnicode_InternMortal(tstate->interp, &name);
     if (tp->tp_setattro != NULL) {
         err = (*tp->tp_setattro)(v, name, value);
         Py_DECREF(name);