From 48605be12883a486942e65bad07214ee6efe407e Mon Sep 17 00:00:00 2001
From: "R. David Murray" <rdmurray@bitdance.com>
Date: Wed, 24 Feb 2010 02:31:27 +0000
Subject: [PATCH] Issue 7975: in python 2.6 bsddb.dbshelve switched from
 DictMixin to MutableMapping, and thereby lost functionality because the
 replacement functionality was implemented incorrectly or incompletely). 
 Since bsddb isn't in py3k, this patch just goes back to using DictMixin in
 order to correct the regression.

---
 Lib/bsddb/dbshelve.py | 21 ++++++---------------
 Misc/NEWS             |  2 ++
 2 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/Lib/bsddb/dbshelve.py b/Lib/bsddb/dbshelve.py
index 1706ca86f40..7c875b47380 100644
--- a/Lib/bsddb/dbshelve.py
+++ b/Lib/bsddb/dbshelve.py
@@ -59,16 +59,11 @@ else:
         return cPickle.dumps(object, bin=protocol)
 
 
-if sys.version_info[0:2] <= (2, 5) :
-    try:
-        from UserDict import DictMixin
-    except ImportError:
-        # DictMixin is new in Python 2.3
-        class DictMixin: pass
-    MutableMapping = DictMixin
-else :
-    import collections
-    MutableMapping = collections.MutableMapping
+try:
+    from UserDict import DictMixin
+except ImportError:
+    # DictMixin is new in Python 2.3
+    class DictMixin: pass
 
 #------------------------------------------------------------------------
 
@@ -111,7 +106,7 @@ def open(filename, flags=db.DB_CREATE, mode=0660, filetype=db.DB_HASH,
 class DBShelveError(db.DBError): pass
 
 
-class DBShelf(MutableMapping):
+class DBShelf(DictMixin):
     """A shelf to hold pickled objects, built upon a bsddb DB object.  It
     automatically pickles/unpickles data objects going to/from the DB.
     """
@@ -162,10 +157,6 @@ class DBShelf(MutableMapping):
         else:
             return self.db.keys()
 
-    if sys.version_info[0:2] >= (2, 6) :
-        def __iter__(self) :
-            return self.db.__iter__()
-
 
     def open(self, *args, **kwargs):
         self.db.open(*args, **kwargs)
diff --git a/Misc/NEWS b/Misc/NEWS
index 5dc3a7b610b..ee77d5dd13d 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -30,6 +30,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #7975: correct regression in dict methods supported by bsddb.dbshelve.
+
 - Issue #7959: ctypes callback functions are now registered correctly
   with the cylce garbage collector.