Issue #27792: force int return type for modulo operations involving bools.

Lib/test/test_bool.py

@@ -96,6 +96,13 @@ class BoolTest(unittest.TestCase):
         self.assertEqual(False/1, 0)
         self.assertIsNot(False/1, False)
 
+        self.assertEqual(True%1, 0)
+        self.assertIsNot(True%1, False)
+        self.assertEqual(True%2, 1)
+        self.assertIsNot(True%2, True)
+        self.assertEqual(False%1, 0)
+        self.assertIsNot(False%1, False)
+
         for b in False, True:
             for i in 0, 1, 2:
                 self.assertEqual(b**i, int(b)**i)

Misc/NEWS

@@ -10,6 +10,10 @@ What's New in Python 3.6.0 beta 1
 Core and Builtins
 -----------------
 
+- Issue #27792: The modulo operation applied to ``bool`` and other
+  ``int`` subclasses now always returns an ``int``. Previously
+  the return type depended on the input values. Patch by Xiang Zhang.
+
 - Issue #26984: int() now always returns an instance of exact int.
 
 - Issue #25604: Fix a minor bug in integer true division; this bug could

Objects/longobject.c

@@ -2458,8 +2458,11 @@ long_divrem(PyLongObject *a, PyLongObject *b,
         *pdiv = (PyLongObject*)PyLong_FromLong(0);
         if (*pdiv == NULL)
             return -1;
-        Py_INCREF(a);
-        *prem = (PyLongObject *) a;
+        *prem = (PyLongObject *)long_long((PyObject *)a);
+        if (*prem == NULL) {
+            Py_CLEAR(*pdiv);
+            return -1;
+        }
         return 0;
     }
     if (size_b == 1) {