From 09ca19208f7c9aa52e71b50cf53cc369612e3fce Mon Sep 17 00:00:00 2001
From: supakeen <39536295+supakeen@users.noreply.github.com>
Date: Sun, 5 Apr 2020 09:02:30 +0200
Subject: [PATCH] Add isNil check to custom Content-Length. (#13867)
 [backport:1.2]

Related to #13866.
---
 lib/pure/asynchttpserver.nim | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/pure/asynchttpserver.nim b/lib/pure/asynchttpserver.nim
index a9ea4780fb..7fbbf38ea3 100644
--- a/lib/pure/asynchttpserver.nim
+++ b/lib/pure/asynchttpserver.nim
@@ -99,8 +99,9 @@ proc respond*(req: Request, code: HttpCode, content: string,
 
   if headers != nil:
     msg.addHeaders(headers)
-    
-  if not headers.hasKey("Content-Length"):
+
+  # If the headers did not contain a Content-Length use our own
+  if headers.isNil() or not headers.hasKey("Content-Length"):
     msg.add("Content-Length: ")
     # this particular way saves allocations:
     msg.addInt content.len