From 848244ad0449a1906004ee0d7ccda3162d07e929 Mon Sep 17 00:00:00 2001
From: Luca Wehrstedt <lerks@users.sourceforge.net>
Date: Sun, 30 Oct 2011 17:37:29 +0100
Subject: [PATCH] Add Etag header on HEAD requests for StaticFileHandler.

---
 tornado/web.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tornado/web.py b/tornado/web.py
index 78267b3ae..86447bdc4 100644
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -1485,6 +1485,10 @@ class StaticFileHandler(RequestHandler):
 
         if not include_body:
             self.set_header("Content-Length", os.path.getsize(abspath))
+            with open(abspath, "rb") as file:
+                hasher = hashlib.sha1()
+                hasher.update(file.read())
+                self.set_header("Etag", '"%s"' % hasher.hexdigest())
             return
         file = open(abspath, "rb")
         try:
-- 
2.47.2