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<<'

     1

PROG=		pop3d

     2

MAN=		pop3d.8

     3

CFLAGS+=	-Wall -Wstrict-prototypes -Wmissing-prototypes

     4

CFLAGS+=	-Wmissing-declarations -Wshadow -Wpointer-arith

     5

CFLAGS+=	-Wcast-qual -Wsign-compare

     6

CFLAGS+=	-DIO_SSL

     7

DEBUG=		-g

     8

SRCS=		pop3d.c pop3e.c session.c maildrop.c maildir.c mbox.c util.c

     9

SRCS+=		imsgev.c iobuf.c ioev.c

    10

SRCS+=		ssl.c ssl_privsep.c

    11

LDADD+=		-levent -lssl -lcrypto -lutil

    12

DPADD=		${LIBEVENT} ${LIBSSL} ${LIBCRYPTO} ${LIBUTIL}

    13

    14

.include <bsd.prog.mk>