LP #142667: update _reader to use new cache in _resetCache.

NEWS.txt

+What's new in ZODB3 3.4.5?
+==========================
+Release date: 09-Oct-2008 (internal release for Zope 2.8.10)
+
+Connection
+----------
+
+- (3.4.5) Reset ``_cache`` on a connection's ``_reader`` object when
+  resetting the cache, to prevent reads from the old cache object, e.g.
+  during Zope2's auto-refresh of products.
+  (https://bugs.launchpad.net/zodb/+bug/142667).
+
 What's new in ZODB3 3.4.4?
 ==========================
 Release date: 14-Jul-2006 (internal release for Zope 2.8.8)

src/ZODB/Connection.py

@@ -928,6 +928,8 @@ class Connection(ExportImport, object):
         self._invalidated.clear()
         cache_size = self._cache.cache_size
         self._cache = cache = PickleCache(self, cache_size)
+        if getattr(self, '_reader', None) is not None:
+            self._reader._cache = cache
 
     ##########################################################################
     # Python protocol

src/ZODB/tests/testConnection.py

@@ -140,6 +140,14 @@ class ConnectionDotAdd(unittest.TestCase):
         self.datamgr.tpc_finish(self.transaction)
         self.assert_(obj._p_oid not in self.datamgr._storage._stored)
 
+    def check__resetCacheResetsReader(self):
+        # https://bugs.launchpad.net/zodb/+bug/142667
+        old_cache = self.datamgr._cache
+        self.datamgr._resetCache()
+        new_cache = self.datamgr._cache
+        self.failIf(new_cache is old_cache)
+        self.failUnless(self.datamgr._reader._cache is new_cache)
+
 class UserMethodTests(unittest.TestCase):
 
     # add isn't tested here, because there are a bunch of traditional