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.

1 files changed, 11 insertions, 13 deletions

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 42d71e5..00d6ab3 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -3434,7 +3434,7 @@ PyDict_Contains(PyObject *op, PyObject *key)
 
 /* Internal version of PyDict_Contains used when the hash value is already known */
 int
-_PyDict_Contains(PyObject *op, PyObject *key, Py_hash_t hash)
+_PyDict_Contains_KnownHash(PyObject *op, PyObject *key, Py_hash_t hash)
 {
     PyDictObject *mp = (PyDictObject *)op;
     PyObject *value;
@@ -3446,6 +3446,16 @@ _PyDict_Contains(PyObject *op, PyObject *key, Py_hash_t hash)
     return (ix != DKIX_EMPTY && value != NULL);
 }
 
+int
+_PyDict_ContainsId(PyObject *op, struct _Py_Identifier *key)
+{
+    PyObject *kv = _PyUnicode_FromId(key); /* borrowed */
+    if (kv == NULL) {
+        return -1;
+    }
+    return PyDict_Contains(op, kv);
+}
+
 /* Hack to implement "key in dict" */
 static PySequenceMethods dict_as_sequence = {
     0,                          /* sq_length */
@@ -3590,18 +3600,6 @@ PyTypeObject PyDict_Type = {
     .tp_vectorcall = dict_vectorcall,
 };
 
-PyObject *
-_PyDict_GetItemId(PyObject *dp, struct _Py_Identifier *key)
-{
-    PyObject *kv;
-    kv = _PyUnicode_FromId(key); /* borrowed */
-    if (kv == NULL) {
-        PyErr_Clear();
-        return NULL;
-    }
-    return PyDict_GetItem(dp, kv);
-}
-
 /* For backward compatibility with old dictionary interface */
 
 PyObject *