Fixed bug #1620: New @spam.getter property syntax modifies the property in place.
I added also the feature that a @prop.getter decorator does not overwrite the doc string of the property if it was given as an argument to property().
diff --git a/Misc/NEWS b/Misc/NEWS
index 0d420d0..3c95ca5 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
 Core and builtins
 -----------------
 
+- Issue #1620: New property decorator syntax was modifying the decorator
+  in place instead of creating a new decorator object.
+
 - Issue #1580: New free format floating point representation based on
   "Floating-Point Printer Sample Code", by Robert G. Burger. For example
   repr(11./5) now returns '2.2' instead of '2.2000000000000002'.