src/http/ngx_http_upstream.c:542: error: Integer Overflow L2
  ([0, `r->uri_changes`] - 1):unsigned32 by call to `ngx_http_upstream_connect`.

src/http/ngx_http_upstream.c:422:1: Parameter `r->uri_changes`
420. 
421. 
422. static void
     ^
423. ngx_http_upstream_init_request(ngx_http_request_t *r)
424. {

src/http/ngx_http_upstream.c:542:13: Call
540.             }
541. 
542.             ngx_http_upstream_connect(r, u);
                 ^
543. 
544.             return;

src/http/ngx_http_upstream.c:1028:1: Parameter `r->uri_changes`
  1026. 
  1027. 
  1028. static void
        ^
  1029. ngx_http_upstream_connect(ngx_http_request_t *r, ngx_http_upstream_t *u)
  1030. {

src/http/ngx_http_upstream.c:1073:9: Call
  1071.     if (rc == NGX_BUSY) {
  1072.         ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "no live upstreams");
  1073.         ngx_http_upstream_next(r, u, NGX_HTTP_UPSTREAM_FT_NOLIVE);
                ^
  1074.         return;
  1075.     }

src/http/ngx_http_upstream.c:2703:1: Parameter `r->uri_changes`
    2701. 
    2702. 
    2703. static void
          ^
    2704. ngx_http_upstream_next(ngx_http_request_t *r, ngx_http_upstream_t *u,
    2705.     ngx_uint_t ft_type)

src/http/ngx_http_upstream.c:2760:9: Call
    2758. 
    2759.     if (r->connection->error) {
    2760.         ngx_http_upstream_finalize_request(r, u,
                  ^
    2761.                                            NGX_HTTP_CLIENT_CLOSED_REQUEST);
    2762.         return;

src/http/ngx_http_upstream.c:2843:1: Parameter `r->uri_changes`
      2841. 
      2842. 
      2843. static void
            ^
      2844. ngx_http_upstream_finalize_request(ngx_http_request_t *r,
      2845.     ngx_http_upstream_t *u, ngx_int_t rc)

src/http/ngx_http_upstream.c:2952:5: Call
      2950.     }
      2951. 
      2952.     ngx_http_finalize_request(r, rc);
                ^
      2953. }
      2954. 

src/http/ngx_http_request.c:1847:1: Parameter `r->uri_changes`
        1845. 
        1846. 
        1847. void
              ^
        1848. ngx_http_finalize_request(ngx_http_request_t *r, ngx_int_t rc)
        1849. {

src/http/ngx_http_request.c:2017:9: Call
        2015.     }
        2016. 
        2017.     if (ngx_http_post_action(r) == NGX_OK) {
                      ^
        2018.         return;
        2019.     }

src/http/ngx_http_request.c:2846:1: Parameter `r->uri_changes`
          2844. 
          2845. 
          2846. static ngx_int_t
                ^
          2847. ngx_http_post_action(ngx_http_request_t *r)
          2848. {

src/http/ngx_http_request.c:2869:9: Call
          2867. 
          2868.     if (clcf->post_action.data[0] == '/') {
          2869.         ngx_http_internal_redirect(r, &clcf->post_action, NULL);
                        ^
          2870. 
          2871.     } else {

src/http/ngx_http_core_module.c:2172:1: <LHS trace>
2170. 
2171. 
2172. ngx_int_t
      ^
2173. ngx_http_internal_redirect(ngx_http_request_t *r,
2174.     ngx_str_t *uri, ngx_str_t *args)

src/http/ngx_http_core_module.c:2172:1: Parameter `r->uri_changes`
            2170. 
            2171. 
            2172. ngx_int_t
                  ^
            2173. ngx_http_internal_redirect(ngx_http_request_t *r,
            2174.     ngx_str_t *uri, ngx_str_t *args)

src/http/ngx_http_core_module.c:2178:5: Binary operation: ([0, r->uri_changes] - 1):unsigned32 by call to `ngx_http_upstream_connect` 
            2176.     ngx_http_core_srv_conf_t  *cscf;
            2177. 
            2178.     r->uri_changes--;
                      ^
            2179. 
            2180.     if (r->uri_changes == 0) {
