long(float('nan')) raises an OverflowError as discussed on the mailing list a week ago

Lib/test/test_long.py

@@ -539,7 +539,7 @@ class LongTest(unittest.TestCase):
 
     def test_nan_inf(self):
         self.assertRaises(OverflowError, int, float('inf'))
-        self.assertEqual(int(float('nan')), 0)
+        self.assertRaises(OverflowError, int, float('nan'))
 
 def test_main():
     test_support.run_unittest(LongTest)

Misc/NEWS

@@ -12,6 +12,9 @@ What's New in Python 3.0a3?
 Core and Builtins
 -----------------
 
+- Object/longobject.c: long(float('nan')) raises an OverflowError instead
+  of returning 0.
+
 - Issue #1762972: __file__ points to the source file instead of the pyc/pyo
   file if the py file exists.
 

Objects/longobject.c

@@ -255,7 +255,9 @@ PyLong_FromDouble(double dval)
 		return NULL;
 	}
 	if (Py_IS_NAN(dval)) {
-		return PyLong_FromLong(0L);
+		PyErr_SetString(PyExc_OverflowError,
+			"cannot convert float NaN to int");
+		return NULL;
 	}
 	if (dval < 0.0) {
 		neg = 1;