Issue #1869: Fix a couple of minor round() issues.
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index 6671f2c..19ce9ec 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -1224,6 +1224,9 @@
         self.assertEqual(round(-5.5), -6)
         self.assertEqual(round(-6.5), -7)
 
+        # Issue #1869: integral floats should remain unchanged
+        self.assertEqual(round(5e15+1), 5e15+1)
+
         # Check behavior on ints
         self.assertEqual(round(0), 0)
         self.assertEqual(round(8), 8)