Fix round function failing on Decimal objects

Author: tpict

src/future/builtins/newround.py

@@ -38,11 +38,14 @@ def newround(number, ndigits=None):
         if 'numpy' in repr(type(number)):
             number = float(number)
 
-    if not PY26:
-        d = Decimal.from_float(number).quantize(exponent,
-                                            rounding=ROUND_HALF_EVEN)
+    if isinstance(d, Decimal):
+        d = number
     else:
-        d = from_float_26(number).quantize(exponent, rounding=ROUND_HALF_EVEN)
+        if not PY26:
+            d = Decimal.from_float(number).quantize(exponent,
+                                                rounding=ROUND_HALF_EVEN)
+        else:
+            d = from_float_26(number).quantize(exponent, rounding=ROUND_HALF_EVEN)
 
     if return_int:
         return int(d)