src/http/ngx_http_variables.c:788: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned64 by call to `ngx_http_arg`.

src/http/ngx_http_variables.c:785:5: Assignment
783.     ngx_str_t   value;
784. 
785.     len = name->len - (sizeof("arg_") - 1);
         ^
786.     arg = name->data + sizeof("arg_") - 1;
787. 

src/http/ngx_http_variables.c:788:9: Call
786.     arg = name->data + sizeof("arg_") - 1;
787. 
788.     if (ngx_http_arg(r, arg, len, &value) != NGX_OK) {
             ^
789.         v->not_found = 1;
790.         return NGX_OK;

src/http/ngx_http_parse.c:1486:1: <LHS trace>
1484. 
1485. 
1486. ngx_int_t
      ^
1487. ngx_http_arg(ngx_http_request_t *r, u_char *name, size_t len, ngx_str_t *value)
1488. {

src/http/ngx_http_parse.c:1486:1: Parameter `len`
  1484. 
  1485. 
  1486. ngx_int_t
        ^
  1487. ngx_http_arg(ngx_http_request_t *r, u_char *name, size_t len, ngx_str_t *value)
  1488. {

src/http/ngx_http_parse.c:1502:13: Binary operation: ([0, +oo] - 1):unsigned64 by call to `ngx_http_arg` 
  1500.         /* we need '=' after name, so drop one char from last */
  1501. 
  1502.         p = ngx_strlcasestrn(p, last - 1, name, len - 1);
                    ^
  1503. 
  1504.         if (p == NULL) {
