segfault during session close #245

Hard to reproduce but have seen multiple times. Occurs for cases that involve closing session (either due to malformed messages or if other side closes sessions).

(gdb) where
#0 0x00007f50ac945f0c in nc_session_close (session=0x30329a0,
reason=NC_SESSION_TERM_OTHER)
at /home/bhupesh/libnetconf/src/session.c:1354
#1 0x00007f50ac948e80 in nc_session_receive (session=0x30329a0, timeout=100,
msg=0x7fff11c5aa50) at /home/bhupesh/libnetconf/src/session.c:2357
#2 0x00007f50ac94690f in nc_session_recv_msg (session=0x30329a0, timeout=100,
msg=0x7fff11c5aa50) at /home/bhupesh/libnetconf/src/session.c:2366
#3 0x00007f50ac946683 in nc_session_recv_reply (session=0x30329a0,
timeout=10000, reply=0x7fff11c5aaa8)
at /home/bhupesh/libnetconf/src/session.c:2412
#4 0x00007f50ac945fea in announce_nc_session_closing (session=0x30329a0)
at /home/bhupesh/libnetconf/src/session.c:1173
#5 0x00007f50ac945b63 in nc_session_close (session=0x30329a0,
reason=NC_SESSION_TERM_OTHER)
at /home/bhupesh/libnetconf/src/session.c:1231
#6 0x00007f50ac948e80 in nc_session_receive (session=0x30329a0, timeout=100,
msg=0x7fff11c5acd0) at /home/bhupesh/libnetconf/src/session.c:2357
#7 0x00007f50ac94690f in nc_session_recv_msg (session=0x30329a0, timeout=100,
msg=0x7fff11c5acd0) at /home/bhupesh/libnetconf/src/session.c:2366
#8 0x00007f50ac946683 in nc_session_recv_reply (session=0x30329a0,
timeout=-1, reply=0x7fff11c5adc0)
at /home/bhupesh/libnetconf/src/session.c:2412
#9 0x00007f50ac949914 in nc_session_send_recv (session=0x30329a0,
rpc=0x20afc80, reply=0x7fff11c5adc0)
at /home/bhupesh/libnetconf/src/session.c:3039
#10 0x0000000000406570 in ?? ()
#11 0x00007fff11c5ae20 in ?? ()
#12 0x0000000001e958d0 in ?? ()
#13 0x0000000000000000 in ?? ()