bugfix: upstream_truncation.patch: 1. 504 error code in ngx_http_upstream_finalize_request resulted in calling special response handler even when the response header has been sent; 2. use 502 status code in ngx_http_upstream_finalize_request when upstream data truncation happens.

patches/nginx-1.2.7-upstream_truncation.patch

@@ -1,5 +1,5 @@
 --- nginx-1.2.7/src/http/ngx_http_upstream.c	2013-02-11 06:39:49.000000000 -0800
-+++ nginx-1.2.7-patched/src/http/ngx_http_upstream.c	2013-04-05 12:24:34.108742922 -0700
++++ nginx-1.2.7-patched/src/http/ngx_http_upstream.c	2013-04-06 17:16:54.444520038 -0700
 @@ -2399,7 +2399,7 @@ ngx_http_upstream_process_non_buffered_u
  
      if (c->read->timedout) {
@@ -25,7 +25,7 @@
                  }
  
 +                if (upstream->read->eof || upstream->read->error) {
-+                    ngx_http_upstream_finalize_request(r, u, NGX_ERROR);
++                    ngx_http_upstream_finalize_request(r, u, NGX_HTTP_BAD_GATEWAY);
 +                    return;
 +                }
 +
@@ -52,19 +52,21 @@
 +            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
 +                           "http upstream exit: %p", p->out);
 +
-+            ngx_http_upstream_finalize_request(r, u, NGX_ERROR);
++            ngx_http_upstream_finalize_request(r, u, NGX_HTTP_BAD_GATEWAY);
 +            return;
 +       }
      }
  
      if (p->downstream_error) {
-@@ -3087,7 +3104,8 @@ ngx_http_upstream_finalize_request(ngx_h
+@@ -3087,9 +3104,9 @@ ngx_http_upstream_finalize_request(ngx_h
  
      if (u->header_sent
          && rc != NGX_HTTP_REQUEST_TIME_OUT
 -        && (rc == NGX_ERROR || rc >= NGX_HTTP_SPECIAL_RESPONSE))
-+        && rc != NGX_HTTP_GATEWAY_TIME_OUT
 +        && rc >= NGX_HTTP_SPECIAL_RESPONSE)
      {
-         rc = 0;
+-        rc = 0;
++        rc = NGX_ERROR;
      }
+ 
+     if (rc == NGX_DECLINED) {