利用tcpcopy(离线加速功能)压力测试，发现bug一处

[wangbin579]

Program terminated with signal 6, Aborted.
#0 0x000000356a4328a5 in raise () from /lib64/libc.so.6

Missing separate debuginfos, use: debuginfo-install glibc-2.12-1.107.el6.x86_64 nss-softokn-freebl-3.12.9-11.el6.x86_64 openssl-1.0.0-27.el6_4.2.x86_64 pcre-7.8-6.el6.x86_64 zlib-1.2.3-29.el6.x86_64
(gdb) bt
#0 0x000000356a4328a5 in raise () from /lib64/libc.so.6
#1 0x000000356a434085 in abort () from /lib64/libc.so.6
#2 0x000000000042eeab in ngx_debug_point () at src/os/unix/ngx_process.c:603
#3 0x0000000000409922 in ngx_output_chain (ctx=0xfe8978, in=0xfe8718)

at src/core/ngx_output_chain.c:114

#4 0x000000000045c918 in ngx_http_upstream_send_request (r=0x1027880, u=0xfe88f8)

at src/http/ngx_http_upstream.c:1433

#5 0x000000000045cb94 in ngx_http_upstream_send_request_handler (r=0x1027880, u=0xfe88f8)

at src/http/ngx_http_upstream.c:1534

#6 0x000000000045bcc9 in ngx_http_upstream_handler (ev=0x7f2ffa5220a8)

at src/http/ngx_http_upstream.c:966

#7 0x0000000000432f17 in ngx_epoll_process_events (cycle=0xf8cf00, timer=38028, flags=1)

at src/event/modules/ngx_epoll_module.c:714

#8 0x000000000042606e in ngx_process_events_and_timers (cycle=0xf8cf00) at src/event/ngx_event.c:249
#9 0x000000000043125d in ngx_worker_process_cycle (cycle=0xf8cf00, data=0x1)

at src/os/unix/ngx_process_cycle.c:807

#10 0x000000000042e1f2 in ngx_spawn_process (cycle=0xf8cf00, proc=0x4310f2 <ngx_worker_process_cycle>,

data=0x1, name=0x4a9c68 "worker process", respawn=-3) at src/os/unix/ngx_process.c:198

#11 0x000000000043048e in ngx_start_worker_processes (cycle=0xf8cf00, n=2, type=-3)

at src/os/unix/ngx_process_cycle.c:362

#12 0x000000000042fc26 in ngx_master_process_cycle (cycle=0xf8cf00)

at src/os/unix/ngx_process_cycle.c:136

#13 0x000000000040364a in main (argc=1, argv=0x7fff991e4168) at src/core/nginx.c:41

-rw------- 1 wangbin wangbin 5259264 Jul 1 12:22 core.18294

2013/07/01 12:22:59 [alert] 18294#0: *17417 zero size buf in output t:1 r:0 f:0 0000000001050941 0000000001050948-0000000001050948 0000000000000000 0-0 while sending request to upstream, client: 123.120.8.27, server: test.163.com,
request: "POST /jetspeed/portal/media-type/html/user/admin/page/default.psml HTTP/1.1",
upstream: "hmux://xxx.xxx.xxx.217:7802", host: "test.163.com:18081",
referrer: "http://test.163.com:18081/jetspeed/portal/media-type/html/user/admin/page/default.psml/js_pane/338"

2013/07/01 12:22:59 [notice] 18292#0: signal 17 (SIGCHLD) received
2013/07/01 12:22:59 [alert] 18292#0: worker process 18294 exited on signal 6 (core dumped)
2013/07/01 12:22:59 [notice] 18292#0: start worker process 19526
2013/07/01 12:22:59 [notice] 18292#0: signal 29 (SIGIO) received

[wangbin579]

Fixed