From 9b87b079b47bb688752fd99b6bd5280d69354a02 Mon Sep 17 00:00:00 2001
From: frmdstryr <frmdstryr@protonmail.com>
Date: Fri, 8 May 2026 14:49:05 -0400
Subject: [PATCH] Update atomset

---
 atom/src/atomset.cpp  | 14 ++++++++------
 tests/test_atomset.py | 27 +++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/atom/src/atomset.cpp b/atom/src/atomset.cpp
index 58f3721d..fb09bf45 100644
--- a/atom/src/atomset.cpp
+++ b/atom/src/atomset.cpp
@@ -67,6 +67,8 @@ PyObject* validate_value( AtomSet* set, PyObject* value )
 PyObject* validate_set( AtomSet* set, PyObject* value )
 {
     cppy::ptr val_set( PySet_New( 0 ) );
+	if ( !val_set )
+		return 0;  // LCOV_EXCL_LINE set new failed
 	cppy::ptr value_iter = PyObject_GetIter(value);
 	if( !value_iter ) {
 		return 0;
@@ -85,6 +87,8 @@ PyObject* validate_set( AtomSet* set, PyObject* value )
             return 0;
         }
 	}
+	if ( PyErr_Occurred() )
+		return 0;
 	return val_set.release();
 }
 
@@ -111,11 +115,7 @@ int AtomSet_clear( AtomSet* self )
 int AtomSet_traverse( AtomSet* self, visitproc visit, void* arg )
 {
 	Py_VISIT( self->m_value_validator );
-#if PY_VERSION_HEX >= 0x03090000
-    // This was not needed before Python 3.9 (Python issue 35810 and 40217)
     Py_VISIT(Py_TYPE(self));
-#endif
-    // PySet_type is not heap allocated so it does visit the type
 	return PySet_Type.tp_traverse( pyobject_cast( self ), visit, arg );
 }
 
@@ -346,7 +346,8 @@ int AtomSet::Update( AtomSet* set, PyObject* value )
 	{
 		// Method call return Py_None or 0. We make sure to decref Py_None and
 		// return -1 in case of error.
-		r_temp = PyObject_CallFunctionObjArgs( SetMethods::update, pyobject_cast( set ), value, NULL );
+		PyObject* args[] = { pyobject_cast( set ), value };
+		r_temp = PyObject_Vectorcall( SetMethods::update, args, 2 | PY_VECTORCALL_ARGUMENTS_OFFSET, 0 );
 		return !r_temp ? -1 : 0;
 	}
 	cppy::ptr temp( cppy::incref( value ) );
@@ -361,7 +362,8 @@ int AtomSet::Update( AtomSet* set, PyObject* value )
 	}
 	// Method call return Py_None or 0. We make sure to decref Py_None and
 	// return -1 in case of error.
-	r_temp = PyObject_CallFunctionObjArgs( SetMethods::update, pyobject_cast( set ), temp.get(), NULL );
+	PyObject* args[] = { pyobject_cast( set ), temp.get() };
+	r_temp = PyObject_Vectorcall( SetMethods::update, args, 2 | PY_VECTORCALL_ARGUMENTS_OFFSET, 0 );
 	return !r_temp ? -1 : 0;
 }
 
diff --git a/tests/test_atomset.py b/tests/test_atomset.py
index 75fb011f..e169969e 100644
--- a/tests/test_atomset.py
+++ b/tests/test_atomset.py
@@ -124,3 +124,30 @@ def test_operations(atom_set, member, op, valid, result, invalid):
     if invalid is not None:
         with pytest.raises(TypeError):
             op(getattr(atom_set, member), invalid)
+
+
+def test_set_errors():
+    """Test extremely unlikely cases"""
+
+    class NonIterableSet(set):
+        def __iter__(self):
+            raise ValueError("Cannot iter")
+
+    class IterableErrorSet(set):
+        def __iter__(self):
+            def gen():
+                yield from set(self)
+                raise ValueError("Bad iter")
+
+            return gen()
+
+    class Obj(Atom):
+        items = Set(str)
+
+    obj = Obj()
+    with pytest.raises(ValueError) as excinfo:
+        obj.items.update(NonIterableSet("a"))
+    assert "Cannot iter" in excinfo.exconly()
+    with pytest.raises(ValueError) as excinfo:
+        obj.items.update(IterableErrorSet("a"))
+    assert "Bad iter" in excinfo.exconly()