bugfix: wrong pipelined request body length when request body is parent's request body. (#1814)

Author: zhuizhuhaomeng

src/ngx_http_lua_subrequest.c

@@ -1637,6 +1637,7 @@ ngx_http_lua_copy_request_headers(ngx_http_request_t *sr,
 {
     ngx_table_elt_t                 *clh, *header;
     ngx_list_part_t                 *part;
+    ngx_chain_t                     *in;
     ngx_uint_t                       i;
     u_char                          *p;
     off_t                            len;
@@ -1653,8 +1654,11 @@ ngx_http_lua_copy_request_headers(ngx_http_request_t *sr,
     if (sr->request_body && !pr_not_chunked) {
 
         /* craft our own Content-Length */
+        len = 0;
 
-        len = sr->request_body->buf ? ngx_buf_size(sr->request_body->buf) : 0;
+        for (in = sr->request_body->bufs; in; in = in->next) {
+            len += ngx_buf_size(in->buf);
+        }
 
         clh = ngx_list_push(&sr->headers_in.headers);
         if (clh == NULL) {