From 8934e6ef53771dbc6fb8e04d991976c13b422928 Mon Sep 17 00:00:00 2001
From: Fidget-Spinner <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Tue, 22 Jun 2021 19:09:20 +0800
Subject: [PATCH 1/2] Fix crash in union object with bad __module__

---
 Lib/test/test_types.py                        |  9 ++++++++
 .../2021-06-22-19-08-19.bpo-44483.eq2f7T.rst  |  2 ++
 Objects/unionobject.c                         | 23 ++++++++++++++++---
 3 files changed, 31 insertions(+), 3 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2021-06-22-19-08-19.bpo-44483.eq2f7T.rst

diff --git a/Lib/test/test_types.py b/Lib/test/test_types.py
index 767c3d06a4f583..d3e315a196b514 100644
--- a/Lib/test/test_types.py
+++ b/Lib/test/test_types.py
@@ -747,6 +747,15 @@ def __eq__(self, other):
                 with self.assertRaises(TypeError):
                     issubclass(list, type_)
 
+    def test_or_type_operator_with_bad_module(self):
+        class TypeVar:
+            @property
+            def __module__(self):
+                1 / 0
+        # Crashes in Issue44483
+        with self.assertRaises(ZeroDivisionError):
+            str | TypeVar()
+
     def test_ellipsis_type(self):
         self.assertIsInstance(Ellipsis, types.EllipsisType)
 
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-06-22-19-08-19.bpo-44483.eq2f7T.rst b/Misc/NEWS.d/next/Core and Builtins/2021-06-22-19-08-19.bpo-44483.eq2f7T.rst
new file mode 100644
index 00000000000000..ea54e79acfd9d8
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2021-06-22-19-08-19.bpo-44483.eq2f7T.rst	
@@ -0,0 +1,2 @@
+Fix a crash in ``types.Union`` objects when creating a union of an object
+with bad ``__module__`` field.
diff --git a/Objects/unionobject.c b/Objects/unionobject.c
index 05350363eed63f..79781d2631dee8 100644
--- a/Objects/unionobject.c
+++ b/Objects/unionobject.c
@@ -284,6 +284,19 @@ is_new_type(PyObject *obj)
     return is_typing_module(obj);
 }
 
+// Emulates short-circuiting behavior of the ``||`` operator
+// while also checking negative values.
+#define CHECK_RES(obj, check) { \
+    int result = check(obj); \
+    if (result < 0) { \
+        goto fail; \
+    } \
+    else if (result > 0) { \
+        return 1; \
+    } \
+}
+
+// Returns 1 on true, 0 on false, and -1 on error.
 static int
 is_unionable(PyObject *obj)
 {
@@ -291,13 +304,17 @@ is_unionable(PyObject *obj)
         return 1;
     }
     PyTypeObject *type = Py_TYPE(obj);
+    CHECK_RES(obj, is_typevar);
+    CHECK_RES(obj, is_new_type);
+    CHECK_RES(obj, is_special_form);
     return (
-        is_typevar(obj) ||
-        is_new_type(obj) ||
-        is_special_form(obj) ||
+        // The following checks never fail.
         PyType_Check(obj) ||
         PyObject_TypeCheck(obj, &Py_GenericAliasType) ||
         type == &_Py_UnionType);
+
+fail:
+    return -1;
 }
 
 PyObject *

From 1b8f932e13fc11f2a83a422d4f5312fb01597dec Mon Sep 17 00:00:00 2001
From: Fidget-Spinner <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Tue, 22 Jun 2021 20:21:51 +0800
Subject: [PATCH 2/2] Apply Serhiy's comments

Co-Authored-By: Serhiy Storchaka <3659035+serhiy-storchaka@users.noreply.github.com>
---
 Objects/unionobject.c | 20 +++++++-------------
 1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/Objects/unionobject.c b/Objects/unionobject.c
index 79781d2631dee8..a66d61524dcfc7 100644
--- a/Objects/unionobject.c
+++ b/Objects/unionobject.c
@@ -286,13 +286,10 @@ is_new_type(PyObject *obj)
 
 // Emulates short-circuiting behavior of the ``||`` operator
 // while also checking negative values.
-#define CHECK_RES(obj, check) { \
-    int result = check(obj); \
-    if (result < 0) { \
-        goto fail; \
-    } \
-    else if (result > 0) { \
-        return 1; \
+#define CHECK_RES(res) { \
+    int result = res; \
+    if (result) { \
+       return result; \
     } \
 }
 
@@ -304,17 +301,14 @@ is_unionable(PyObject *obj)
         return 1;
     }
     PyTypeObject *type = Py_TYPE(obj);
-    CHECK_RES(obj, is_typevar);
-    CHECK_RES(obj, is_new_type);
-    CHECK_RES(obj, is_special_form);
+    CHECK_RES(is_typevar(obj));
+    CHECK_RES(is_new_type(obj));
+    CHECK_RES(is_special_form(obj));
     return (
         // The following checks never fail.
         PyType_Check(obj) ||
         PyObject_TypeCheck(obj, &Py_GenericAliasType) ||
         type == &_Py_UnionType);
-
-fail:
-    return -1;
 }
 
 PyObject *