Merge remote-tracking branch 'origin/master' into transactions-and-threading

Conflicts:
	CHANGES.rst

CHANGES.rst

@@ -2,7 +2,7 @@
  Change History
 ================
 
-5.0.1 (2016-09-09)
+5.0.1 (unreleased)
 ==================
 
 - Fix an AttributeError that DemoStorage could raise if it was asked
@@ -12,6 +12,11 @@
 - Call _p_resolveConflict() even if a conflicting change doesn't change the
   state. This reverts to the behaviour of 3.10.3 and older.
 
+- Closing a Connection now reverts its ``transaction_manager`` to
+  None. This helps prevent errors and release resources when the
+  ``transaction_manager`` was the (default) thread-local manager. See
+  `issue 114 <https://github.com/zopefoundation/ZODB/issues/114>`_.
+
 - Many docstrings have been improved.
 
 5.0.0 (2016-09-06)

doc/reference/storages.rst

@@ -8,7 +8,7 @@ Storage interfaces
 ==================
 
 There are various storage implementations that implement standard
-storage interfaces. Thet differ primarily in their constructors.
+storage interfaces. They differ primarily in their constructors.
 
 Application code rarely calls storage methods, and those it calls are
 generally called indirectly through databases.  There are
@@ -144,7 +144,7 @@ Options:
 Noteworthy non-included storages
 ================================
 
-A number of important ZODB storages are distriubuted separately, including:
+A number of important ZODB storages are distributed separately, including:
 
 RelStorage
   `RelStorage <http://relstorage.readthedocs.io/en/latest/>`_
@@ -153,7 +153,7 @@ RelStorage
   storing data in relational databases.  Unlike the included storages,
   multiple processes can share the same database.
 
-  For more imformation, see http://relstorage.readthedocs.io/en/latest/.
+  For more information, see http://relstorage.readthedocs.io/en/latest/.
 
 ZEO
   `ZEO <https://github.com/zopefoundation/ZEO>`_ is a client-server
@@ -161,7 +161,7 @@ ZEO
   and use ZEO clients in your application.  Unlike the included
   storages, multiple processes can share the same database.
 
-  For more imformation, see https://github.com/zopefoundation/ZEO.
+  For more information, see https://github.com/zopefoundation/ZEO.
 
 ZRS
   `ZRS <https://github.com/zc/zrs>`_
@@ -173,14 +173,14 @@ ZRS
   committed on the primary, they're copied asynchronously to
   secondaries.
 
-  For more imformation, see https://github.com/zc/zrs.
+  For more information, see https://github.com/zc/zrs.
 
 zlibstorage
   `zlibstorage <https://pypi.python.org/pypi/zc.zlibstorage>`_
   compresses database records using the compression
   algorithm used by `gzip <http://www.gzip.org/>`_.
 
-  For more imformation, see https://pypi.python.org/pypi/zc.zlibstorage.
+  For more information, see https://pypi.python.org/pypi/zc.zlibstorage.
 
 beforestorage
   `beforestorage <https://pypi.python.org/pypi/zc.beforestorage>`_
@@ -188,12 +188,12 @@ beforestorage
   be changing.  This can be useful to provide a non-changing view of a
   production database for use with a :class:`~ZODB.DemoStorage.DemoStorage`.
 
-  For more imformation, see https://pypi.python.org/pypi/zc.beforestorage.
+  For more information, see https://pypi.python.org/pypi/zc.beforestorage.
 
 cipher.encryptingstorage
   `cipher.encryptingstorage
   <https://pypi.python.org/pypi/cipher.encryptingstorage/>`_ provided
   compression and encryption of database records.
 
-  For more informayion see,
+  For more information, see
   https://pypi.python.org/pypi/cipher.encryptingstorage/.

src/ZODB/Connection.py

@@ -295,7 +295,9 @@ class Connection(ExportImport, object):
 
         self._debug_info = ()
 
-        if self.opened:
+        if self.opened and self.transaction_manager is not None:
+            # transaction_manager could be None if one of the __onCloseCallbacks
+            # closed the DB already, .e.g, ZODB.connection() does this.
             self.transaction_manager.unregisterSynch(self)
 
         if primary:
@@ -318,6 +320,9 @@ class Connection(ExportImport, object):
         if am is not None:
             am.closedConnection(self)
 
+        # Drop transaction manager to release resources and help prevent errors
+        self.transaction_manager = None
+
     def db(self):
         """Returns a handle to the database this connection belongs to."""
         return self._db
@@ -911,6 +916,7 @@ class Connection(ExportImport, object):
                 c._storage.release()
             c._storage = c._normal_storage = None
             c._cache = PickleCache(self, 0, 0)
+            c.transaction_manager = None
 
     ##########################################################################
     # Python protocol

src/ZODB/DB.py

@@ -637,7 +637,8 @@ class DB(object):
 
         @self._connectionMap
         def _(c):
-            c.transaction_manager.abort()
+            if c.transaction_manager is not None:
+                c.transaction_manager.abort()
             c.afterCompletion = c.newTransaction = c.close = noop
             c._release_resources()