There are a lot of calls like this:
this->dispatcher->raise_event(this->dispatcher, "...", 0,
b->finalize(b));
However, if finalize() fails, e.g. because a previous call to add()
failed due to the size limit, it returns NULL. This then caused a
segmentation fault in raise_event() when it interacted with that value.
Closesstrongswan/strongswan#1278