I can confirm that there is no memory leak ;)
Of course, it might still be possible to find out some, but if you have
a lot of them, most probably you missed something.
You can check the eXosip code for a reference implementation
on what's needed.
If you only removed the transaction (I guess with "osip_remove_transaction"?)
then, it's not enough. At some point, you need to call:
In eXosip, I do this once when I'm sure the transaction is not used anymore
and when i don't need it anymore.