src/http/ngx_http_upstream.c:2453: error: Integer Overflow L2
  ([0, `r->uri_changes`] - 1):unsigned32 by call to `ngx_http_upstream_process_upgraded`.

src/http/ngx_http_upstream.c:2384:1: Parameter `r->uri_changes`
2382. 
2383. 
2384. static void
      ^
2385. ngx_http_upstream_upgrade(ngx_http_request_t *r, ngx_http_upstream_t *u)
2386. {

src/http/ngx_http_upstream.c:2453:9: Call
2451.         || r->header_in->pos != r->header_in->last)
2452.     {
2453.         ngx_http_upstream_process_upgraded(r, 0, 1);
              ^
2454.     }
2455. }

src/http/ngx_http_upstream.c:2488:1: Parameter `r->uri_changes`
  2486. 
  2487. 
  2488. static void
        ^
  2489. ngx_http_upstream_process_upgraded(ngx_http_request_t *r,
  2490.     ngx_uint_t from_upstream, ngx_uint_t do_write)

src/http/ngx_http_upstream.c:2511:9: Call
  2509.         c->timedout = 1;
  2510.         ngx_connection_error(c, NGX_ETIMEDOUT, "client timed out");
  2511.         ngx_http_upstream_finalize_request(r, u, NGX_HTTP_REQUEST_TIME_OUT);
                ^
  2512.         return;
  2513.     }

src/http/ngx_http_upstream.c:3296:1: Parameter `r->uri_changes`
    3294. 
    3295. 
    3296. static void
          ^
    3297. ngx_http_upstream_finalize_request(ngx_http_request_t *r,
    3298.     ngx_http_upstream_t *u, ngx_int_t rc)

src/http/ngx_http_upstream.c:3425:9: Call
    3423. 
    3424.     if (r->header_only) {
    3425.         ngx_http_finalize_request(r, rc);
                  ^
    3426.         return;
    3427.     }

src/http/ngx_http_request.c:2198:1: Parameter `r->uri_changes`
      2196. 
      2197. 
      2198. void
            ^
      2199. ngx_http_finalize_request(ngx_http_request_t *r, ngx_int_t rc)
      2200. {

src/http/ngx_http_request.c:2236:13: Call
      2234.         || c->error)
      2235.     {
      2236.         if (ngx_http_post_action(r) == NGX_OK) {
                        ^
      2237.             return;
      2238.         }

src/http/ngx_http_request.c:3256:1: Parameter `r->uri_changes`
        3254. 
        3255. 
        3256. static ngx_int_t
              ^
        3257. ngx_http_post_action(ngx_http_request_t *r)
        3258. {

src/http/ngx_http_request.c:3283:9: Call
        3281. 
        3282.     if (clcf->post_action.data[0] == '/') {
        3283.         ngx_http_internal_redirect(r, &clcf->post_action, NULL);
                      ^
        3284. 
        3285.     } else {

src/http/ngx_http_core_module.c:2551:1: <LHS trace>
2549. 
2550. 
2551. ngx_int_t
      ^
2552. ngx_http_internal_redirect(ngx_http_request_t *r,
2553.     ngx_str_t *uri, ngx_str_t *args)

src/http/ngx_http_core_module.c:2551:1: Parameter `r->uri_changes`
          2549. 
          2550. 
          2551. ngx_int_t
                ^
          2552. ngx_http_internal_redirect(ngx_http_request_t *r,
          2553.     ngx_str_t *uri, ngx_str_t *args)

src/http/ngx_http_core_module.c:2557:5: Binary operation: ([0, r->uri_changes] - 1):unsigned32 by call to `ngx_http_upstream_process_upgraded` 
          2555.     ngx_http_core_srv_conf_t  *cscf;
          2556. 
          2557.     r->uri_changes--;
                    ^
          2558. 
          2559.     if (r->uri_changes == 0) {
