Are the changes in the other ticket needed to implement new tests?
Or is it possible to include tests here?
It is not possible to add any tests to this issue before exposing the error code. I will implement new tests when bpo-16379 will be resolved.
Aviv the patch makes in itself.
I think that this issue should be dependent on bpo-16379 as the behavior of the sqlite module will no be changed after this patch until bpo-16379 is resolved. In addition there will be some "rebase" issues that will need to be solved.