crash while processing malformed query with 0 question with OPT
(gdb) bt
#0 knot_wire_is_pointer (pos=0x557aac60607c "\300\f") at ./libknot/packet/wire.h:901
#1 knot_wire_get_pointer (pos=0x557aac60607c "\300\f") at libknot/packet/wire.c:122
#2 0x00007f6bee68c105 in knot_wire_seek_label (wire=0x557aac605ff0 "", lp=<optimized out>) at ./libknot/packet/wire.h:910
#3 knot_wire_next_label (wire=0x557aac605ff0 "", lp=<optimized out>) at ./libknot/packet/wire.h:920
#4 knot_dname_labels (name=<optimized out>, pkt=0x557aac605ff0 "") at libknot/dname.c:781
#5 0x00007f6bee68e7e8 in knot_pkt_put (pkt=0x557aac5c9760, compr_hint=<optimized out>, rr=0x557aac5c9868, flags=<optimized out>)
at libknot/packet/pkt.c:563
#6 0x00007f6bee9254e9 in kr_resolve_finish () from /usr/local/lib/libkres.so.6
#7 0x0000557aa81ecb26 in ?? ()
#8 0x0000000000000106 in ?? ()
#9 0x0000557aac5c7eb0 in ?? ()
#10 0x0000000000000106 in ?? ()
#11 0x0000000000000008 in ?? ()
#12 0x00007f6beedad010 in ?? ()
#13 0x0000557aa81edae9 in ?? ()
#14 0x0000000000000000 in ?? ()
(gdb) f 5
#5 0x00007f6bee68e7e8 in knot_pkt_put (pkt=0x557aac5c9760,
compr_hint=<optimized out>, rr=0x557aac5c9868, flags=<optimized out>)
at libknot/packet/pkt.c:563
563 libknot/packet/pkt.c: No such file or directory.
(gdb) print pkt
$4 = (knot_pkt_t *) 0x557aac5c9760
(gdb) print *pkt
$5 = {wire = 0x557aac605ff0 "", size = 12, max_size = 65535, parsed = 0,
reserved = 0, qname_size = 0, rrset_count = 0, flags = 2,
opt_rr = 0x557aac5c9868, tsig_rr = 0x0, tsig_wire = {pos = 0x0, len = 0},
current = KNOT_ADDITIONAL, sections = {{pkt = 0x557aac5c9760, pos = 0,
count = 0}, {pkt = 0x557aac5c9760, pos = 0, count = 0}, {
pkt = 0x557aac5c9760, pos = 0, count = 0}}, rrset_allocd = 16,
rr_info = 0x557aac5c9898, rr = 0x557aac5c9ad8, mm = {ctx = 0x557aac5c7e40,
alloc = 0x557aa81faee0 <mp_alloc>, free = 0x0}, compr = {
wire = 0x557aac605ff0 "", rrinfo = 0x557aac5c9898, suffix = {pos = 12,
labels = 0 '\000'}}}
(gdb) print rr
$6 = (const knot_rrset_t *) 0x557aac5c9868
(gdb) print *rr
$7 = {owner = 0x557aac5c9860 "", type = 41, rclass = 1536, rrs = {
rr_count = 1, data = 0x557aac5c9890 ""}, additional = 0x0}
it shouldnt read qname if it's not there https://github.com/CZ-NIC/knot/blob/master/src/libknot/packet/pkt.c#L522