gh-145166: Address review comments - deduplicate tests and fix indentation

Author: HELLPUSYY666

Lib/test/datetimetester.py

@@ -5133,16 +5133,17 @@ def test_pickling(self):
             self.assertEqual(derived.tzname(), 'cookie')
         self.assertEqual(orig.__reduce__(), orig.__reduce_ex__(2))
 
-    def test_fromutc_subclass_new_returns_non_datetime(self):
-        call_count = 0
-
+    def _make_evil_datetime_class(self):
         class EvilDatetime(self.theclass):
+            sabotage = False
             def __new__(cls, *args, **kwargs):
-                nonlocal call_count
-                call_count += 1
-                if call_count > 1:
+                if cls.sabotage:
                     return bytearray(b'\x00' * 200)
                 return super().__new__(cls, *args, **kwargs)
+        return EvilDatetime
+
+    def test_fromutc_subclass_new_returns_non_datetime(self):
+        EvilDatetime = self._make_evil_datetime_class()
 
         class SimpleTZ(tzinfo):
             def utcoffset(self, dt): return timedelta(hours=1)
@@ -5151,39 +5152,26 @@ def tzname(self, dt):    return "Test"
 
         tz = SimpleTZ()
         dt = EvilDatetime(2000, 1, 1, 12, 0, 0, tzinfo=tz)
+        EvilDatetime.sabotage = True
         with self.assertRaises(TypeError):
             tz.fromutc(dt)
 
     def test_fromutc_subclass_new_returns_non_datetime_with_delta(self):
-        call_count = 0
+        EvilDatetime = self._make_evil_datetime_class()
 
-        class EvilDatetime(self.theclass):
-            def __new__(cls, *args, **kwargs):
-                nonlocal call_count
-                call_count += 1
-                if call_count > 1:
-                    return bytearray(b'\x00' * 200)
-                return super().__new__(cls, *args, **kwargs)
         class SimpleTZ(tzinfo):
             def utcoffset(self, dt): return timedelta(hours=2)
             def dst(self, dt):       return timedelta(hours=1)
             def tzname(self, dt):    return "Test"
 
         tz = SimpleTZ()
         dt = EvilDatetime(2000, 1, 1, 12, 0, 0, tzinfo=tz)
+        EvilDatetime.sabotage = True
         with self.assertRaises(TypeError):
             tz.fromutc(dt)
 
     def test_utctimetuple_subclass_new_returns_non_datetime(self):
-        call_count = 0
-
-        class EvilDatetime(self.theclass):
-            def __new__(cls, *args, **kwargs):
-                nonlocal call_count
-                call_count += 1
-                if call_count > 1:
-                    return bytearray(b'\x00' * 200)
-                return super().__new__(cls, *args, **kwargs)
+        EvilDatetime = self._make_evil_datetime_class()
 
         class SimpleTZ(tzinfo):
             def utcoffset(self, dt): return timedelta(hours=5)
@@ -5192,6 +5180,7 @@ def tzname(self, dt):    return "Test"
 
         tz = SimpleTZ()
         dt = EvilDatetime(2000, 6, 15, 12, 0, 0, tzinfo=tz)
+        EvilDatetime.sabotage = True
         with self.assertRaises(TypeError):
             dt.utctimetuple()
 

Modules/_datetimemodule.c

@@ -4168,6 +4168,7 @@ tzinfo_fromutc(PyObject *self, PyObject *dt)
     result = add_datetime_timedelta((PyDateTime_DateTime *)dt, delta, 1);
     if (result == NULL)
         goto Fail;
+
     Py_DECREF(dst);
     dst = call_dst(GET_DT_TZINFO(dt), result);
     if (dst == NULL)
@@ -6210,14 +6211,14 @@ add_datetime_timedelta(PyDateTime_DateTime *date, PyDateTime_Delta *delta,
     }
 
     PyObject *result = new_datetime_subclass_ex(year, month, day,
-                                        hour, minute, second, microsecond,
-                                        HASTZINFO(date) ? date->tzinfo : Py_None,
-                                        Py_TYPE(date));
-        if (result != NULL && !PyDateTime_Check(result)) {
-            PyErr_Format(PyExc_TypeError,
-                        "datetime arithmetic on a subclass returned "
-                        "non-datetime (type %.200s)",
-                        Py_TYPE(result)->tp_name);
+                                                hour, minute, second, microsecond,
+                                                HASTZINFO(date) ? date->tzinfo : Py_None,
+                                                Py_TYPE(date));
+    if (result != NULL && !PyDateTime_Check(result)) {
+        PyErr_Format(PyExc_TypeError,
+                     "datetime arithmetic on a subclass returned "
+                     "non-datetime (type %.200s)",
+                     Py_TYPE(result)->tp_name);
             Py_DECREF(result);
             return NULL;
         }