--- nginx-1.4.3/src/http/modules/ngx_http_gzip_filter_module.c	2013-10-08 05:07:14.000000000 -0700
+++ nginx-1.4.3-patched/src/http/modules/ngx_http_gzip_filter_module.c	2013-10-26 17:14:22.132109569 -0700
@@ -370,11 +370,12 @@ ngx_http_gzip_body_filter(ngx_http_reque
         }
     }
 
-    if (ctx->nomem) {
+    if (ctx->nomem || in == NULL) {
 
         /* flush busy buffers */
 
-        if (ngx_http_next_body_filter(r, NULL) == NGX_ERROR) {
+        rc = ngx_http_next_body_filter(r, NULL);
+        if (rc == NGX_ERROR) {
             goto failed;
         }
 
@@ -383,6 +384,10 @@ ngx_http_gzip_body_filter(ngx_http_reque
         ngx_chain_update_chains(r->pool, &ctx->free, &ctx->busy, &cl,
                                 (ngx_buf_tag_t) &ngx_http_gzip_filter_module);
         ctx->nomem = 0;
+
+        if (in == NULL) {
+            return rc;
+        }
     }
 
     for ( ;; ) {