Keepalive support in memcached.

src/http/modules/ngx_http_memcached_module.c

diff --git a/src/http/modules/ngx_http_memcached_module.c b/src/http/modules/ngx_http_memcached_module.c
index cdc5869..dbe0fe8 100644
--- a/src/http/modules/ngx_http_memcached_module.c
+++ b/src/http/modules/ngx_http_memcached_module.c
@@ -366,6 +366,7 @@
 
         u->headers_in.status_n = 404;
         u->state->status = 404;
+        u->keepalive = 1;
 
         return NGX_OK;
     }
@@ -426,6 +427,10 @@
         u->length -= bytes;
         ctx->rest -= bytes;
 
+        if (u->length == 0) {
+            u->keepalive = 1;
+        }
+
         return NGX_OK;
     }
 
@@ -463,6 +468,13 @@
     if (ngx_strncmp(last, ngx_http_memcached_end, b->last - last) != 0) {
         ngx_log_error(NGX_LOG_ERR, ctx->request->connection->log, 0,
                       "memcached sent invalid trailer");
+
+        b->last = last;
+        cl->buf->last = last;
+        u->length = 0;
+        ctx->rest = 0;
+
+        return NGX_OK;
     }
 
     ctx->rest -= b->last - last;
@@ -470,6 +482,10 @@
     cl->buf->last = last;
     u->length = ctx->rest;
 
+    if (u->length == 0) {
+        u->keepalive = 1;
+    }
+
     return NGX_OK;
 }