Make close() identical to __del__() for a dumbdbm database. Make
closing idempotent (it used to raise a nuisance exception on the 2nd
close attempt).
Bugfix candidate? Probably, but arguable.
diff --git a/Misc/NEWS b/Misc/NEWS
index 0f329df..9b9b567 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -38,6 +38,9 @@
Library
-------
+- Closing a dumbdbm database more than once is now harmless (it used to
+ raise a nuisance exception on the second close).
+
- It's vital that a dumbdbm database be closed properly, else the
on-disk data and directory files can be left in mutually inconsistent
states. dumbdbm.py's _Database.__del__() method attempted to close