[Varnish] #1737: Assert error in SES_Close()

[Varnish]

#1737: Assert error in SES_Close()
--------------------------------+----------------------
 Reporter:  llavaud             |       Type:  defect
   Status:  new                 |   Priority:  normal
Milestone:                      |  Component:  varnishd
  Version:  trunk               |   Severity:  major
 Keywords:  panic assert error  |
--------------------------------+----------------------
 {{{
 May 18 15:58:58 webcache12 varnishd[140657]: Child (140676) died signal=6
 May 18 15:58:58 webcache12 varnishd[140657]: Child (140676) Panic message:
 Assert error in SES_Close(), cache/cache_session.c line 274:
   Condition(sp->fd >= 0) not true.
 errno = 32 (Broken pipe)
 thread = (cache-worker)
 version = varnish-trunk revision cbb2f5d
 ident = Linux,3.2.0-4-amd64,x86_64,-sfile,-smalloc,-hcritbit,epoll
 Backtrace:
   0x434564: pan_ic+0x134
   0x43bd46: SES_Close+0x56
   0x41bd9d: ESI_Deliver+0x1cd
   0x41ac45: VDP_DeliverObj+0x135
   0x44dda5: V1D_Deliver+0x275
   0x437fe6: cnt_deliver+0x296
   0x4385c9: CNT_Request+0x119
   0x44f5bb: HTTP1_Session+0x77b
   0x43b9f8: ses_req_pool_task+0x68
   0x43c994: SES_pool_accept_task+0x2b4
 req = 0x7f1105447020 {
   sp = 0x7f110353d920, vxid = 2492739,  step = R_STP_DELIVER,
   req_body = R_BODY_NONE,
   restarts = 0, esi_level = 0
   sp = 0x7f110353d920 {
     fd = -1, vxid = 2492738,
     client = client_ip 50724,
     step = S_STP_WORKING,
   },
   worker = 0x7f1106dcbc30 {
     stack = {0x7f1106dcc000 -> 0x7f1106dc0000}
     ws = 0x7f1106dcbe40 {
       id = "wrk",
       {s,f,r,e} = {0x7f1106dcb420,0x7f1106dcb420,(nil),+2040},
     },
   VCL::method = DELIVER,
   VCL::return = deliver,
   VCL::methods = {RECV, PASS, HASH, PURGE, MISS, HIT, DELIVER, SYNTH,
 BACKEND_FETCH, BACKEND_RESPONSE},
   },
   ws = 0x7f11054471d0 {
     id = "req",
     {s,f,r,e} = {0x7f1105448ff8,+2624,+253984,+253984},
   },
   http[req] = {
     ws = 0x7f11054471d0[req]
       "GET",
       "myuri",
       "HTTP/1.1",
       "Accept: text/html, application/xhtml+xml, */*",
       "Referer: http://www.gulli.fr/Jeux/My-Little-Pony/My-Little-Pony-
 Jeu-Rarity",
       "Accept-Language: fr-FR",
       "User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0;
 rv:11.0) like Gecko",
       "DNT: 1",
       "Connection: Keep-Alive",
       "Host: www.gulli.fr",
       "Surrogate-Capability: abc=ESI/1.0",
       "X-Forwarded-For

-- 
Ticket URL: <https://www.varnish-cache.org/trac/ticket/1737>
Varnish <https://varnish-cache.org/>
The Varnish HTTP Accelerator