From 8bf91b8dcafef8e29e76e39851f5cc50bee59937 Mon Sep 17 00:00:00 2001
From: Sam <sam.saffron@gmail.com>
Date: Fri, 19 Jan 2018 17:51:04 +1100
Subject: [PATCH] correct tracking of x runtime

---
 lib/middleware/request_tracker.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/middleware/request_tracker.rb b/lib/middleware/request_tracker.rb
index e544e55516b..2df14da6b04 100644
--- a/lib/middleware/request_tracker.rb
+++ b/lib/middleware/request_tracker.rb
@@ -138,8 +138,8 @@ class Middleware::RequestTracker
     result = @app.call(env)
     info = MethodProfiler.stop
     # possibly transferred?
-    if info
-      env["X-Runtime"] = "%0.6f" % info[:total_duration]
+    if info && (headers = result[1])
+      headers["X-Runtime"] = "%0.6f" % info[:total_duration]
     end
     result
   ensure