Test cases from Cowlishaw, v2.57. All are pased cleanly.
diff --git a/Lib/test/decimaltestdata/ddAdd.decTest b/Lib/test/decimaltestdata/ddAdd.decTest
index 49d89d4..38d511b 100644
--- a/Lib/test/decimaltestdata/ddAdd.decTest
+++ b/Lib/test/decimaltestdata/ddAdd.decTest
@@ -17,7 +17,7 @@
-- IBM UK, PO Box 31, Birmingham Road, Warwick CV34 5JL, UK --
-- mfc@uk.ibm.com --
------------------------------------------------------------------------
-version: 2.56
+version: 2.57
-- This set of tests are for decDoubles only; all arguments are
-- representable in a decDouble
@@ -1029,6 +1029,16 @@
ddadd71707 add 130E-2 -1E0 -> 0.30
ddadd71708 add 1E2 -1E4 -> -9.9E+3
+-- query from Vincent Kulandaisamy
+rounding: ceiling
+ddadd71801 add 7.8822773805862E+277 -5.1757503820663E-21 -> 7.882277380586200E+277 Inexact Rounded
+ddadd71802 add 7.882277380586200E+277 12.341 -> 7.882277380586201E+277 Inexact Rounded
+ddadd71803 add 7.882277380586201E+277 2.7270545046613E-31 -> 7.882277380586202E+277 Inexact Rounded
+
+ddadd71811 add 12.341 -5.1757503820663E-21 -> 12.34100000000000 Inexact Rounded
+ddadd71812 add 12.34100000000000 2.7270545046613E-31 -> 12.34100000000001 Inexact Rounded
+ddadd71813 add 12.34100000000001 7.8822773805862E+277 -> 7.882277380586201E+277 Inexact Rounded
+
-- Gappy coefficients; check residue handling even with full coefficient gap
rounding: half_even