src/http/ngx_http_variables.c:1078: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned64 by call to `ngx_http_arg`.

src/http/ngx_http_variables.c:1075:5: Assignment
1073.     ngx_str_t   value;
1074. 
1075.     len = name->len - (sizeof("arg_") - 1);
          ^
1076.     arg = name->data + sizeof("arg_") - 1;
1077. 

src/http/ngx_http_variables.c:1078:21: Call
1076.     arg = name->data + sizeof("arg_") - 1;
1077. 
1078.     if (len == 0 || ngx_http_arg(r, arg, len, &value) != NGX_OK) {
                          ^
1079.         v->not_found = 1;
1080.         return NGX_OK;

src/http/ngx_http_parse.c:2102:1: <LHS trace>
2100. 
2101. 
2102. ngx_int_t
      ^
2103. ngx_http_arg(ngx_http_request_t *r, u_char *name, size_t len, ngx_str_t *value)
2104. {

src/http/ngx_http_parse.c:2102:1: Parameter `len`
  2100. 
  2101. 
  2102. ngx_int_t
        ^
  2103. ngx_http_arg(ngx_http_request_t *r, u_char *name, size_t len, ngx_str_t *value)
  2104. {

src/http/ngx_http_parse.c:2118:13: Binary operation: ([0, +oo] - 1):unsigned64 by call to `ngx_http_arg` 
  2116.         /* we need '=' after name, so drop one char from last */
  2117. 
  2118.         p = ngx_strlcasestrn(p, last - 1, name, len - 1);
                    ^
  2119. 
  2120.         if (p == NULL) {
