fixed outdated transaction.commit(1) call in ZODBMountPoint.SimpleTrailblazer

doc/CHANGES.txt

@@ -8,6 +8,9 @@ Zope Changes
 
     Bugs fixed
 
+      - fixed outdated transaction.commit(1) call in 
+        ZODBMountPoint.SimpleTrailblazer
+
       - Launchpad #239636:  Ensure that HEAD requests lock an empty body
         for NotFound errors.
 

lib/python/Products/ZODBMountPoint/MountedObject.py

@@ -60,7 +60,7 @@ class SimpleTrailblazer:
         o = context.restrictedTraverse(id)
         # Commit a subtransaction to assign the new object to
         # the correct database.
-        transaction.commit(1)
+        transaction.savepoint(optimistic=True)
         return o
 
     def traverseOrConstruct(self, path, omit_final=0):