nchan_longpoll_multipart_response will crash the worker

[mapledan]

The worker crashed when subscribe is a longpoll response that using "nchan_longpoll_multipart_response raw".
Here is nginx error log:

2018/08/06 12:25:01 [alert] 13463#0: *89 zero size buf in output t:1 r:0 f:1 0000000000002020 0000000000000000-0000000000000000 2E3141473D61675F 0-0, server: localhost
2018/08/06 12:25:01 [alert] 13457#0: worker process 13462 exited on signal 11 (core dumped)
2018/08/06 12:25:02 [alert] 13457#0: worker process 13463 exited on signal 11 (core dumped)

The coredump backtrace:

Core was generated by `nginx: worker process                                                         '.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x0000000100000000 in ?? ()
(gdb) bt
#0  0x0000000100000000 in ?? ()
#1  0x000000000042564f in ngx_log_error_core (level=3, log=0x18fab8c, err=9, fmt=0x5dc4e6 "pread() \"%s\" failed") at src/core/ngx_log.c:149
#2  0x00000000004619d0 in ngx_read_file (file=0x190d030, buf=0x18fc2a0 "\330\022\036\252\260\177", size=18446744073683719248, offset=25832368) at src/os/unix/ngx_files.c:43
#3  0x000000000042b66c in ngx_output_chain_copy_buf (ctx=0x1910d18) at src/core/ngx_output_chain.c:595
#4  0x000000000042ac15 in ngx_output_chain (ctx=0x1910d18, in=0x190dcd0) at src/core/ngx_output_chain.c:173
#5  0x00000000004d3266 in ngx_http_copy_filter (r=0x18f9ed0, in=0x190dcd0) at src/http/ngx_http_copy_filter_module.c:152
#6  0x00000000004c340e in ngx_http_range_body_filter (r=0x18f9ed0, in=0x190dcd0) at src/http/modules/ngx_http_range_filter_module.c:628
#7  0x000000000048003f in ngx_http_output_filter (r=0x18f9ed0, in=0x190dcd0) at src/http/ngx_http_core_module.c:1986
#8  0x0000000000520793 in nchan_output_filter_generic (r=0x18f9ed0, msg=0x0, in=0x190dcd0) at /opt/nchan-1.2.1/src/util/nchan_output.c:261
#9  0x00000000005208c2 in nchan_output_filter (r=0x18f9ed0, in=0x190dcd0) at /opt/nchan-1.2.1/src/util/nchan_output.c:296
#10 0x0000000000530891 in longpoll_multipart_respond (fsub=0x18a2080) at /opt/nchan-1.2.1/src/subscribers/longpoll.c:415
#11 0x000000000053098f in longpoll_respond_status (self=0x18a2080, status_code=204, status_line=0x0, status_body=0x0) at /opt/nchan-1.2.1/src/subscribers/longpoll.c:435
#12 0x000000000053ea26 in spool_respond_general (self=0x189fd68, msg=0x0, code=204, code_data=0x0, notice=0) at /opt/nchan-1.2.1/src/store/spool.c:619
#13 0x000000000053da3a in spool_nextmsg (spool=0x174d6b8, new_last_id=0x7fb0a12c9200) at /opt/nchan-1.2.1/src/store/spool.c:279
#14 0x000000000053dcf0 in spool_fetch_msg_callback (code=5, msg=0x7fb0a12c9200, data=0x1905e30) at /opt/nchan-1.2.1/src/store/spool.c:334
#15 0x0000000000550cc2 in nchan_memstore_handle_get_message_reply (msg=0x7fb0a12c9200, findmsg_status=MSG_FOUND, data=0x18a25e0) at /opt/nchan-1.2.1/src/store/memory/memstore.c:2766
#16 0x0000000000544480 in receive_get_message_reply (sender=4, d=0x7ffcd31fe320) at /opt/nchan-1.2.1/src/store/memory/ipc-handlers.c:609
#17 0x0000000000545fca in memstore_ipc_alert_handler (sender=4, code=10, data=0x7ffcd31fe320) at /opt/nchan-1.2.1/src/store/memory/ipc-handlers.c:1062
#18 0x0000000000541dcd in ipc_read_handler (ev=0x1858f90) at /opt/nchan-1.2.1/src/store/memory/ipc.c:457
#19 0x000000000045c295 in ngx_event_process_posted (cycle=0x1745150, posted=0xb3cb00 <ngx_posted_events>) at src/event/ngx_event_posted.c:33
#20 0x00000000004599a8 in ngx_process_events_and_timers (cycle=0x1745150) at src/event/ngx_event.c:259
#21 0x0000000000468e6e in ngx_worker_process_cycle (cycle=0x1745150, data=0x3) at src/os/unix/ngx_process_cycle.c:749
#22 0x0000000000465539 in ngx_spawn_process (cycle=0x1745150, proc=0x468d87 <ngx_worker_process_cycle>, data=0x3, name=0x5dd35b "worker process", respawn=-3) at src/os/unix/ngx_process.c:198
#23 0x0000000000467c22 in ngx_start_worker_processes (cycle=0x1745150, n=12, type=-3) at src/os/unix/ngx_process_cycle.c:358
#24 0x00000000004671c8 in ngx_master_process_cycle (cycle=0x1745150) at src/os/unix/ngx_process_cycle.c:130
#25 0x0000000000422c91 in main (argc=3, argv=0x7ffcd31fe9d8) at src/core/nginx.c:375

#427

[slact]

Nchan version? Nginx config?

[mapledan]

Nchan: 1.2.1
Nginx: 1.12.2

nginx config:

        location ~ /sub/(\w+)/msg$ {
            nchan_channel_id $1;
            nchan_subscriber;
            nchan_authorize_request /nchan-auth;
            nchan_redis_pass redis_cluster;
            nchan_longpoll_multipart_response raw;
            nchan_subscriber_compound_etag_message_id on;
        }

        location = /nchan-auth {
            internal;
            proxy_pass http://127.0.0.1/;
            proxy_pass_request_body off;
            proxy_set_header Content-Length "";
            proxy_set_header Host 'nchan-auth';
            proxy_set_header X-Original-URI $request_uri;
        }

I have emailed you the core dump file.