From fcd0b0b544f59d5a4bd9a5132d7a124cca78d4a0 Mon Sep 17 00:00:00 2001
From: Jan Dohl <jan@legxaro.de>
Date: Sat, 3 Feb 2018 23:58:19 +0100
Subject: [PATCH] Fix erroneous 304 of StaticFileHandler

StaticFileHandler would return a 304 despite the client sending
a non-matching Etag header when If-Modified-Since matches
---
 tornado/web.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tornado/web.py b/tornado/web.py
index 5fa3abd8b..7bf5415d0 100644
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -2499,8 +2499,9 @@ class StaticFileHandler(RequestHandler):
 
         .. versionadded:: 3.1
         """
-        if self.check_etag_header():
-            return True
+        # If client sent If-None-Match, use it, ignore If-Modified-Since
+        if self.request.headers.get('If-None-Match'):
+            return self.check_etag_header()
 
         # Check the If-Modified-Since, and don't send the result if the
         # content has not been modified
-- 
2.47.2