Invalid handling of ISC_R_SHUTTINGDOWN in resquery_response

#0  rctx_respinit (query=query@entry=0x7fab98271600, fctx=fctx@entry=0x7fab98274000, result=result@entry=ISC_R_SHUTTINGDOWN, region=region@entry=0x0, rctx=rctx@entry=0x7fab99ffdf20) at resolver.c:7917
#1  0x00007fabbaf2c74f in resquery_response (eresult=ISC_R_SHUTTINGDOWN, region=0x0, arg=0x7fab98271600) at resolver.c:7498
#2  0x00007fabbae4d610 in udp_dispentry_cancel (resp=0x7fab9820a000, result=result@entry=ISC_R_SHUTTINGDOWN) at dispatch.c:1666
#3  0x00007fabbae50c73 in dispentry_cancel (resp=<optimized out>, result=result@entry=ISC_R_SHUTTINGDOWN) at dispatch.c:1782
#4  0x00007fabbae5179e in send_done (handle=<optimized out>, result=ISC_R_SHUTTINGDOWN, cbarg=<optimized out>) at dispatch.c:2108
#5  0x00007fabbb2207f7 in isc__nm_sendcb_job (arg=<optimized out>) at netmgr/netmgr.c:2058
#6  0x00007fabbb238f49 in isc__job_cb (idle=0x7fabb4925c88) at job.c:75
#7  0x00007fabbb1728a1 in ?? () from /lib/x86_64-linux-gnu/libuv.so.1
#8  0x00007fabbb16b9b9 in uv_run () from /lib/x86_64-linux-gnu/libuv.so.1
#9  0x00007fabbb23f718 in loop_run (loop=loop@entry=0x7fabb76c66f0) at loop.c:273
#10 0x00007fabbb23f7b8 in loop_thread (arg=0x7fabb76c66f0) at loop.c:299
#11 0x00007fabbb254b27 in isc__trampoline_run (arg=0x56329f853810) at trampoline.c:202
#12 0x00007fabba4fbfd4 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#13 0x00007fabba57c66c in ?? () from /lib/x86_64-linux-gnu/libc.so.6

The region is NULL when eresult is ISC_R_SHUTTINGDOWN, but rctx_respinit dereferences region.