Bug fixed

---------

- Database connections didn't invalidate cache entries when conflict
  errors were raised in response to checkCurrentSerialInTransaction
  errors. Normally, this shouldn't be a problem, since there should be
  pending invalidations for these oids which will cause the object to
  be invalidated. There have been issues with ZEO persistent cache
  management that have caused out of date data to remain in the cache.
  (It's possible that the last of these were addressed in the
  3.10.0b5.) Invalidating read data when there is a conflict error
  provides some extra insurance.

src/CHANGES.txt

@@ -2,6 +2,23 @@
  Change History
 ================
 
+3.10.0b6 (2010-09-??)
+=====================
+
+Bugs fixed
+----------
+
+- Database connections didn't invalidate cache entries when conflict
+  errors were raised in response to checkCurrentSerialInTransaction
+  errors. Normally, this shouldn't be a problem, since there should be
+  pending invalidations for these oids which will cause the object to
+  be invalidated. There have been issues with ZEO persistent cache
+  management that have caused out of date data to remain in the cache.
+  (It's possible that the last of these were addressed in the
+  3.10.0b5.) Invalidating read data when there is a conflict error
+  provides some extra insurance.
+
+
 3.10.0b5 (2010-09-02)
 =====================
 

src/ZODB/Connection.py

@@ -557,8 +557,12 @@ class Connection(ExportImport, object):
             self._commit(transaction)
 
         for oid, serial in self._readCurrent.iteritems():
-            self._storage.checkCurrentSerialInTransaction(
-                oid, serial, transaction)
+            try:
+                self._storage.checkCurrentSerialInTransaction(
+                    oid, serial, transaction)
+            except ConflictError:
+                self._cache.invalidate(oid)
+                raise
 
     def _commit(self, transaction):
         """Commit changes to an object"""
@@ -754,7 +758,13 @@ class Connection(ExportImport, object):
             vote = self._storage.tpc_vote
         except AttributeError:
             return
-        s = vote(transaction)
+        try:
+            s = vote(transaction)
+        except ReadConflictError, v:
+            if v.oid:
+                self._cache.invalidate(v.oid)
+            raise
+
         if s:
             for oid, serial in s:
                 self._handle_serial(oid, serial)

src/ZODB/tests/testConnection.py

@@ -680,6 +680,7 @@ Or if the object it was called on is modified:
 
 If the storage raises a conflict error, it'll be propigated:
 
+    >>> _ = str(conn.root.a) # do read
     >>> bad.add(conn.root.a._p_oid)
     >>> conn.readCurrent(conn.root.a)
     >>> conn.root.b.x += 1
@@ -690,6 +691,10 @@ If the storage raises a conflict error, it'll be propigated:
 
     >>> transaction.abort()
 
+The conflict error will cause the affected object to be invalidated:
+
+    >>> conn.root.a._p_changed
+
 The storage may raise it later:
 
     >>> def checkCurrentSerialInTransaction(oid, serial, trans):
@@ -709,6 +714,7 @@ The storage may raise it later:
 
 It will still be propigated:
 
+    >>> _ = str(conn.root.a) # do read
     >>> conn.readCurrent(conn.root.a)
     >>> conn.root.b.x = +1
     >>> transaction.commit()
@@ -718,6 +724,10 @@ It will still be propigated:
 
     >>> transaction.abort()
 
+The conflict error will cause the affected object to be invalidated:
+
+    >>> conn.root.a._p_changed
+
 Read checks don't leak accross transactions:
 
     >>> conn.readCurrent(conn.root.a)