From 3042b853bcf1919cfb295c8353e9009624c8a415 Mon Sep 17 00:00:00 2001
From: Pierre-Olivier Latour <pol@mac.com>
Date: Sun, 17 Apr 2016 20:07:54 -0700
Subject: [PATCH] Fix

---
 GCDWebServer/Core/GCDWebServerResponse.m | 1 +
 1 file changed, 1 insertion(+)

diff --git a/GCDWebServer/Core/GCDWebServerResponse.m b/GCDWebServer/Core/GCDWebServerResponse.m
index 8357ab7..a5dc537 100644
--- a/GCDWebServer/Core/GCDWebServerResponse.m
+++ b/GCDWebServer/Core/GCDWebServerResponse.m
@@ -241,6 +241,7 @@
 }
 
 - (void)performReadDataWithCompletion:(GCDWebServerBodyReaderCompletionBlock)block {
+  GWS_DCHECK(_opened);
   if ([_reader respondsToSelector:@selector(asyncReadDataWithCompletion:)]) {
     [_reader asyncReadDataWithCompletion:[block copy]];
   } else {