src/http/ngx_http_upstream.c:1556: error: Integer Overflow L2
  ([0, `r->uri_changes`] - 1):unsigned32 by call to `ngx_http_upstream_intercept_errors`.

src/http/ngx_http_upstream.c:1421:1: Parameter `r->uri_changes`
1419. 
1420. 
1421. static void
      ^
1422. ngx_http_upstream_process_header(ngx_http_request_t *r, ngx_http_upstream_t *u)
1423. {

src/http/ngx_http_upstream.c:1552:13: Call
1550.         }
1551. 
1552.         if (ngx_http_upstream_test_next(r, u) == NGX_OK) {
                  ^
1553.             return;
1554.         }

src/http/ngx_http_upstream.c:1608:1: Parameter `r->uri_changes`
  1606. 
  1607. 
  1608. static ngx_int_t
        ^
  1609. ngx_http_upstream_test_next(ngx_http_request_t *r, ngx_http_upstream_t *u)
  1610. {

src/http/ngx_http_upstream.c:1556:13: Call
1554.         }
1555. 
1556.         if (ngx_http_upstream_intercept_errors(r, u) == NGX_OK) {
                  ^
1557.             return;
1558.         }

src/http/ngx_http_upstream.c:1652:1: Parameter `r->uri_changes`
  1650. 
  1651. 
  1652. static ngx_int_t
        ^
  1653. ngx_http_upstream_intercept_errors(ngx_http_request_t *r,
  1654.     ngx_http_upstream_t *u)

src/http/ngx_http_upstream.c:1690:21: Call
  1688. 
  1689.                 if (h == NULL) {
  1690.                     ngx_http_upstream_finalize_request(r, u,
                            ^
  1691.                                                NGX_HTTP_INTERNAL_SERVER_ERROR);
  1692.                     return NGX_OK;

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:1886:13: Call
      1884.         || c->error)
      1885.     {
      1886.         if (ngx_http_post_action(r) == NGX_OK) {
                        ^
      1887.             return;
      1888.         }

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_intercept_errors` 
          2176.     ngx_http_core_srv_conf_t  *cscf;
          2177. 
          2178.     r->uri_changes--;
                    ^
          2179. 
          2180.     if (r->uri_changes == 0) {
