Closes #15973: fix a segmentation fault when comparing timezone objects.

Lib/datetime.py

@@ -1854,6 +1854,8 @@ class timezone(tzinfo):
         return (self._offset, self._name)
 
     def __eq__(self, other):
+        if type(other) != timezone:
+            return False
         return self._offset == other._offset
 
     def __hash__(self):

Lib/test/datetimetester.py

@@ -235,6 +235,8 @@ class TestTimeZone(unittest.TestCase):
         self.assertEqual(timezone(-5 * HOUR), timezone(-5 * HOUR, 'EST'))
         with self.assertRaises(TypeError): timezone(ZERO) < timezone(ZERO)
         self.assertIn(timezone(ZERO), {timezone(ZERO)})
+        self.assertTrue(timezone(ZERO) != None)
+        self.assertFalse(timezone(ZERO) ==  None)
 
     def test_aware_datetime(self):
         # test that timezone instances can be used by datetime

Misc/NEWS

@@ -31,6 +31,9 @@ Library
 Extension Modules
 -----------------
 
+- Issue #15973: Fix a segmentation fault when comparing datetime timezone
+  objects.
+
 - Issue #15977: Fix memory leak in Modules/_ssl.c when the function
   _set_npn_protocols() is called multiple times, thanks to Daniel Sommermann.
 

Modules/_datetimemodule.c

@@ -3215,6 +3215,12 @@ timezone_richcompare(PyDateTime_TimeZone *self,
 {
     if (op != Py_EQ && op != Py_NE)
         Py_RETURN_NOTIMPLEMENTED;
+    if (Py_TYPE(other) != &PyDateTime_TimeZoneType) {
+	if (op == Py_EQ)
+	    Py_RETURN_FALSE;
+	else
+	    Py_RETURN_TRUE;
+    }
     return delta_richcompare(self->offset, other->offset, op);
 }