# HG changeset patch
# User Maxim Dounin <mdounin@mdounin.ru>
# Date 1317122231 0
# Node ID 3549db8ceaf203ec5ad725d7bab10daa4b21507d
# Parent  b9ee14871bf1b15f3f1fe0bf69d7ea9ee19e19ec
Cache: fix for sending of stale responses.

For normal cached responses ngx_http_cache_send() sends last buffer and then
request finalized via ngx_http_finalize_request() call, i.e. everything is
ok.

But for stale responses (i.e. when upstream died, but we have something in
cache) the same ngx_http_cache_send() sends last buffer, but then in
ngx_http_upstream_finalize_request() another last buffer is send.  This
causes duplicate final chunk to appear if chunked encoding is used (and
resulting problems with keepalive connections and so on).

Fix this by not sending in ngx_http_upstream_finalize_request()
another last buffer if we know response was from cache.

diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -3072,7 +3072,12 @@ ngx_http_upstream_finalize_request(ngx_h
 
     r->connection->log->action = "sending to client";
 
-    if (rc == 0) {
+    if (rc == 0
+#if (NGX_HTTP_CACHE)
+        && !r->cached
+#endif
+       )
+    {
         rc = ngx_http_send_special(r, NGX_HTTP_LAST);
     }