commit fb5db7ec58624cab0797b4050735be865d380823
author Serhiy Storchaka <storchaka@gmail.com> Mon Oct 26 08:43:39 2020 +0200
committer GitHub <noreply@github.com> Mon Oct 26 08:43:39 2020 +0200
tree 7b0421bb759ba01f0d735296738472faa4ce11b8
parent 96a9eed2457c05af6953890d89463704c9d99c57

bpo-42006: Stop using PyDict_GetItem, PyDict_GetItemString and _PyDict_GetItemId. (GH-22648)

These functions are considered not safe because they suppress all internal errors
and can return wrong result.  PyDict_GetItemString and _PyDict_GetItemId can
also silence current exception in rare cases.

Remove no longer used _PyDict_GetItemId.
Add _PyDict_ContainsId and rename _PyDict_Contains into
_PyDict_Contains_KnownHash.

Objects/moduleobject.c

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index ee4ed97..c3ceb78 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -477,10 +477,12 @@ PyModule_GetNameObject(PyObject *m)
     }
     d = ((PyModuleObject *)m)->md_dict;
     if (d == NULL ||
-        (name = _PyDict_GetItemId(d, &PyId___name__)) == NULL ||
+        (name = _PyDict_GetItemIdWithError(d, &PyId___name__)) == NULL ||
         !PyUnicode_Check(name))
     {
-        PyErr_SetString(PyExc_SystemError, "nameless module");
+        if (!PyErr_Occurred()) {
+            PyErr_SetString(PyExc_SystemError, "nameless module");
+        }
         return NULL;
     }
     Py_INCREF(name);
@@ -509,10 +511,12 @@ PyModule_GetFilenameObject(PyObject *m)
     }
     d = ((PyModuleObject *)m)->md_dict;
     if (d == NULL ||
-        (fileobj = _PyDict_GetItemId(d, &PyId___file__)) == NULL ||
+        (fileobj = _PyDict_GetItemIdWithError(d, &PyId___file__)) == NULL ||
         !PyUnicode_Check(fileobj))
     {
-        PyErr_SetString(PyExc_SystemError, "module filename missing");
+        if (!PyErr_Occurred()) {
+            PyErr_SetString(PyExc_SystemError, "module filename missing");
+        }
         return NULL;
     }
     Py_INCREF(fileobj);
@@ -721,14 +725,21 @@ module_getattro(PyModuleObject *m, PyObject *name)
     PyErr_Clear();
     if (m->md_dict) {
         _Py_IDENTIFIER(__getattr__);
-        getattr = _PyDict_GetItemId(m->md_dict, &PyId___getattr__);
+        getattr = _PyDict_GetItemIdWithError(m->md_dict, &PyId___getattr__);
         if (getattr) {
             return PyObject_CallOneArg(getattr, name);
         }
-        mod_name = _PyDict_GetItemId(m->md_dict, &PyId___name__);
+        if (PyErr_Occurred()) {
+            return NULL;
+        }
+        mod_name = _PyDict_GetItemIdWithError(m->md_dict, &PyId___name__);
         if (mod_name && PyUnicode_Check(mod_name)) {
             Py_INCREF(mod_name);
-            PyObject *spec = _PyDict_GetItemId(m->md_dict, &PyId___spec__);
+            PyObject *spec = _PyDict_GetItemIdWithError(m->md_dict, &PyId___spec__);
+            if (spec == NULL && PyErr_Occurred()) {
+                Py_DECREF(mod_name);
+                return NULL;
+            }
             Py_XINCREF(spec);
             if (_PyModuleSpec_IsInitializing(spec)) {
                 PyErr_Format(PyExc_AttributeError,
@@ -746,6 +757,9 @@ module_getattro(PyModuleObject *m, PyObject *name)
             Py_DECREF(mod_name);
             return NULL;
         }
+        else if (PyErr_Occurred()) {
+            return NULL;
+        }
     }
     PyErr_Format(PyExc_AttributeError,
                 "module has no attribute '%U'", name);