Issue #25449: Iterating OrderedDict with keys with unstable hash now raises

KeyError in C implementations as well as in Python implementation.

Added tests for OrderedDict subclasses.

Misc/NEWS

@@ -10,6 +10,9 @@ Release date: XXXX-XX-XX
 Core and Builtins
 -----------------
 
+- Issue #25449: Iterating OrderedDict with keys with unstable hash now raises
+  KeyError in C implementations as well as in Python implementation.
+
 - Issue #25395: Fixed crash when highly nested OrderedDict structures were
   garbage collected.
 
@@ -298,6 +301,8 @@ Documentation
 Tests
 -----
 
+- Issue #25449: Added tests for OrderedDict subclasses.
+
 - Issue #25188: Add -P/--pgo to test.regrtest to suppress error output when
   running the test suite for the purposes of a PGO build. Initial patch by
   Alecsandru Patrascu.

Objects/odictobject.c

@@ -1789,6 +1789,8 @@ odictiter_nextkey(odictiterobject *di)
     /* Get the key. */
     node = _odict_find_node(di->di_odict, di->di_current);
     if (node == NULL) {
+        if (!PyErr_Occurred())
+            PyErr_SetObject(PyExc_KeyError, di->di_current);
         /* Must have been deleted. */
         Py_CLEAR(di->di_current);
         return NULL;