From e984e74dcc7ee92a89cbd1bffa1640f30557bab8 Mon Sep 17 00:00:00 2001
From: Willem de Groot <willem@byte.nl>
Date: Fri, 21 Aug 2015 14:51:40 +0200
Subject: [PATCH] Allow multi-line headers

---
 tornado/curl_httpclient.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tornado/curl_httpclient.py b/tornado/curl_httpclient.py
index ae6f114a9..9c9481688 100644
--- a/tornado/curl_httpclient.py
+++ b/tornado/curl_httpclient.py
@@ -454,7 +454,8 @@ class CurlAsyncHTTPClient(AsyncHTTPClient):
         if header_callback is not None:
             self.io_loop.add_callback(header_callback, header_line)
         # header_line as returned by curl includes the end-of-line characters.
-        header_line = header_line.strip()
+        # whitespace at the start should be preserved to allow multi-line headers
+        header_line = header_line.rstrip()
         if header_line.startswith("HTTP/"):
             headers.clear()
             try:
-- 
2.47.2