The sockaddr_storage returned by accept(2) belongs to session and not the listener. Move it to a place where it belongs: struct session.

Stop leaking sock descriptors in error path.

Whitespace.

Merge refactor branch.

Disengaging imsgev is tricky. First imsgev_clear as we know there isn't anything left to be written. Signal imsgev termination by setting iev->terminate = 1(Mind that we are setting it from with the callback). As imsgev would again callback dispatch with IMSGEV_DONE, we cannot free imsgev yet. So iev_maildrop need to exist beyond lifetime of session until IMSGEV_DONE. Allocating it seperately from session. imsgev_close is avoided as it schedules another EV_WRITE which is not needed in our case. This fixes a crash observed consistently with a little perl script to simulate concurrent sessions. Thanks MALLOC_OPTIONS='SFG<<'

Shorten.

space nit.

No use of iev->data, set it to NULL.

Give session a chance to init its imsgev. Let session initiate the process of MAILDROP_INIT. Maildrop now sets up itself and waits for MAILDROP_INIT from session. This would now eliminate the doubt in the earlier setup when priv process forks and the child gets cpu slice first before parent which sends MAILDROP_INIT to an uninitialized imsgev.

mtype, mpath are accessible to maildrop, simplify setup parameters.