Merged revisions 78139 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/branches/py3k

................
  r78139 | r.david.murray | 2010-02-10 19:15:05 -0500 (Wed, 10 Feb 2010) | 15 lines

  Merged revisions 78137 via svnmerge from
  svn+ssh://pythondev@svn.python.org/python/trunk

  ........
    r78137 | r.david.murray | 2010-02-10 17:42:04 -0500 (Wed, 10 Feb 2010) | 8 lines

    Issue 7835:  Shelve's __del__ method calls its close method, and its
    close method refers to an identifier in the global module namespace.
    This means that when __del__ is called during interpreter shutdown (if,
    for example, the calling program still has a pointer to the shelf),
    sometimes that global identifier would wind up being None, causing
    mysterious 'ignored' exceptions.  This patch checks for the possible None
    value first before using the global, thus avoiding the error messages.
  ........
................

2 files changed, 8 insertions, 1 deletions

diff --git a/Lib/shelve.py b/Lib/shelve.py
index fb2fa93..8271dfe 100644
--- a/Lib/shelve.py
+++ b/Lib/shelve.py
@@ -136,7 +136,11 @@ class Shelf(collections.MutableMapping):
             self.dict.close()
         except AttributeError:
             pass
-        self.dict = _ClosedDict()
+        # _ClosedDict can be None when close is called from __del__ during shutdown
+        if _ClosedDict is None:
+            self.dict = None
+        else:
+            self.dict = _ClosedDict()
 
     def __del__(self):
         if not hasattr(self, 'writeback'):
diff --git a/Misc/NEWS b/Misc/NEWS
index c5b971d..054bb3d 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -79,6 +79,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #7835: shelve should no longer produce mysterious warnings during
+  interpreter shutdown.
+
 - Issue #6233: ElementTree failed converting unicode characters to XML
   entities when they could't be represented in the requested output
   encoding.  Patch by Jerry Chen.