mruby_enable_read_request_body, mruby_set_code and mruby_content_handler_code don't work together

[yyamano]

I get a SIGSEGV with the following configuration.

        location /read-request-in-mruby_set {
          mruby_enable_read_request_body on;
          mruby_set_code $body '
             req = Nginx::Request.new
             rc = req.read_body
             Nginx.log Nginx::LOG_ERR, "rc:#{rc}"
             body = req.get_body
             Nginx.log Nginx::LOG_ERR, "body:#{body}"
             body
          ';
          mruby_content_handler_code '
             Nginx.rputs "OK"
          ';
        }

Program received signal SIGSEGV, Segmentation fault.
0x0000000000553546 in ngx_mrb_rputs_inner (mrb=0xbecf90, self=..., with_lf=0)
    at /home/vagrant/ngx_mruby/src/http/ngx_http_mruby_core.c:154
154	  if (ctx->rputs_chain == NULL) {
Missing separate debuginfos, use: debuginfo-install glibc-2.17-106.el7_2.6.x86_64 nss-softokn-freebl-3.16.2.3-13.el7_1.x86_64 openssl-libs-1.0.1e-51.el7_2.5.x86_64 pcre-8.32-15.el7_2.1.x86_64 zlib-1.2.7-15.el7.x86_64
(gdb) bt
#0  0x0000000000553546 in ngx_mrb_rputs_inner (mrb=0xbecf90, self=..., with_lf=0)
    at /home/vagrant/ngx_mruby/src/http/ngx_http_mruby_core.c:154
#1  0x000000000055383c in ngx_mrb_rputs (mrb=0xbecf90, self=...) at /home/vagrant/ngx_mruby/src/http/ngx_http_mruby_core.c:201
#2  0x000000000058534c in mrb_vm_exec (mrb=mrb@entry=0xbecf90, proc=proc@entry=0xc3e1a8, pc=0xd35468)
    at /home/vagrant/ngx_mruby/mruby/src/vm.c:1414
#3  0x00000000005890f9 in mrb_vm_run (mrb=0xbecf90, proc=0xc3e1a8, self=..., stack_keep=<optimized out>)
    at /home/vagrant/ngx_mruby/mruby/src/vm.c:897
#4  0x000000000058b0ae in mrb_run (mrb=<optimized out>, proc=<optimized out>, self=...)
    at /home/vagrant/ngx_mruby/mruby/src/vm.c:2907
#5  0x000000000054e630 in ngx_mrb_run (r=0xbeb5b0, state=0xbe6328, code=0xd451d8, cached=1, result=0x0)
    at /home/vagrant/ngx_mruby/src/http/ngx_http_mruby_module.c:836
#6  0x0000000000550e46 in ngx_http_mruby_content_inline_handler (r=0xbeb5b0)
    at /home/vagrant/ngx_mruby/src/http/ngx_http_mruby_module.c:1577
#7  0x00000000004aeec4 in ngx_http_core_content_phase (r=0xbeb5b0, ph=0xd61188) at src/http/ngx_http_core_module.c:1169
#8  0x00000000004ae247 in ngx_http_core_run_phases (r=0xbeb5b0) at src/http/ngx_http_core_module.c:851
#9  0x00000000004ae1b5 in ngx_http_handler (r=0xbeb5b0) at src/http/ngx_http_core_module.c:834
#10 0x00000000004bd206 in ngx_http_process_request (r=0xbeb5b0) at src/http/ngx_http_request.c:1948
#11 0x00000000004bbb8f in ngx_http_process_request_headers (rev=0xbd9c10) at src/http/ngx_http_request.c:1375
#12 0x00000000004baf55 in ngx_http_process_request_line (rev=0xbd9c10) at src/http/ngx_http_request.c:1048
#13 0x00000000004b9b15 in ngx_http_wait_request_handler (rev=0xbd9c10) at src/http/ngx_http_request.c:506
#14 0x000000000049d183 in ngx_epoll_process_events (cycle=0xbd5530, timer=60000, flags=1)
    at src/event/modules/ngx_epoll_module.c:902
#15 0x000000000048bf0d in ngx_process_events_and_timers (cycle=0xbd5530) at src/event/ngx_event.c:242
#16 0x0000000000499645 in ngx_single_process_cycle (cycle=0xbd5530) at src/os/unix/ngx_process_cycle.c:309
#17 0x0000000000457c90 in main (argc=1, argv=0x7fffffffe408) at src/core/nginx.c:378
(gdb) l
149	  }
150	  if (ns.len == 0) {
151	    return self;
152	  }
153	
154	  if (ctx->rputs_chain == NULL) {
155	    chain = ngx_pcalloc(r->pool, sizeof(ngx_mrb_rputs_chain_list_t));
156	    if (chain == NULL) {
157	      mrb_raise(mrb, E_RUNTIME_ERROR, "failed to allocate memory");
158	    }
(gdb) p ctx
$1 = (ngx_http_mruby_ctx_t *) 0x0
(gdb) p r
$2 = (ngx_http_request_t *) 0xbeb5b0

Here is the client code. It is almost same as test/t/issue-268-test.rb.

#!/usr/bin/env ruby

require 'socket'

request_body = %({"hello": "ngx_mruby"})
headers = <<HEAD.gsub("\n", "\r\n")
POST /read-request-in-mruby_set HTTP/1.0
Content-Type: application/json
User-Agent: issue-268-test
Content-Length: #{request_body.length}
HEAD

Socket.tcp("localhost", 58080) do |s|
  s.print headers
  s.print "\r\n"
  sleep 0.3 # <==== important!
  s.print request_body
  s.close_write
  puts s.read
end

[matsumotory]

Thank you for you report. I'll investigate later.