From be40255e608bb8336b03db2bcfd3a3c64997d316 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nils=20O=2E=20Sel=C3=A5sdal?= <nos@utel.tech>
Date: Mon, 7 Apr 2025 16:25:04 +0200
Subject: [PATCH] Don't send an empty HTTP header.
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This breaks strict middleware..

Signed-off-by: Nils O. Selåsdal <nos@utel.tech>
---
 prometheus_client/exposition.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/prometheus_client/exposition.py b/prometheus_client/exposition.py
index 7427cf93..0bc3632e 100644
--- a/prometheus_client/exposition.py
+++ b/prometheus_client/exposition.py
@@ -132,7 +132,7 @@ def prometheus_app(environ, start_response):
         elif environ['PATH_INFO'] == '/favicon.ico':
             # Serve empty response for browsers
             status = '200 OK'
-            headers = [('', '')]
+            headers = []
             output = b''
         else:
             # Note: For backwards compatibility, the URI path for GET is not