Test cases from Cowlishaw, v2.57. All are pased cleanly.
diff --git a/Lib/test/decimaltestdata/ddEncode.decTest b/Lib/test/decimaltestdata/ddEncode.decTest
index 16264fc..3fa434c 100644
--- a/Lib/test/decimaltestdata/ddEncode.decTest
+++ b/Lib/test/decimaltestdata/ddEncode.decTest
@@ -18,7 +18,7 @@
-- mfc@uk.ibm.com --
------------------------------------------------------------------------
-- [Previously called decimal64.decTest]
-version: 2.56
+version: 2.57
-- This set of tests is for the eight-byte concrete representation.
-- Its characteristics are:
@@ -485,3 +485,6 @@
decd829 apply #2238000115afb55b -> 4294967295
decd830 apply #2238000115afb57a -> 4294967296
decd831 apply #2238000115afb57b -> 4294967297
+
+-- for narrowing
+decd840 apply #2870000000000000 -> 2.000000000000000E-99