When using a database table broker, django-celery-transactions breaks commit_on_success decorator

This is a curious one; I'm only guessing this is the right project to report the bug; I don't see an obvious way to fix it though, and it is a bit of an edge case.

• My function uses @transaction.commit_on_success.
• It saves a model instance that is attached to a search index.
• Via a post_save hook, celery-haystack wants to send the update task to celery.
• django-celery-transactions holds the task back for now.
• My function ends, commit_on_success executes a COMMIT, sets the connection is_dirty flag to False.
• django-celery-transactions, via it's post_commit patching, now triggers the celery task sends.
• Since I'm using the database broker, the database connection is dirtied again in this step.
• Finally, the code of Django's commit_on_success decorator calls leave_transaction_management, which checks the dirty flag and fails with: ```django-celery-transactions`.

This is using Django 1.5 and Haystack 2 Beta.

Start by reproducing the sequence involving Django 1.5's transaction.commit_on_success, the post_save hook, django-celery-transactions' post_commit patching, and a database broker. Trace the connection's is_dirty flag through the final leave_transaction_management call. Done means the Celery task can be sent after commit without the decorator failing.