From 99ee09023682ee014e3846b759917c16528ff997 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A1s=20Marczink=C3=B3?=
 <andris155@users.noreply.github.com>
Date: Sun, 6 Sep 2026 21:32:48 +0200
Subject: [PATCH] Fix PHP Warning: Cannot modify header information headers
 already sent (#9267)

Closes #9229

I restored my accidently deleted patches with @Inverle fixes. This fix is still works perfectly. Sorry. (https://github.com/FreshRSS/FreshRSS/pull/9230)

How to test the feature manually:

With this change:
1. Go to FreshRSS UserCSS extension config
2. Enable the UserCSS and set the CSS code in it.
3. Go to FreshRSS feeds page.
4. Hit the ctrl + F5 button and see no errors in the nginx log.
---
 app/Controllers/extensionController.php | 3 ++-
 app/views/extension/serve.phtml         | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/app/Controllers/extensionController.php b/app/Controllers/extensionController.php
index 599babf7c..547fe80bc 100644
--- a/app/Controllers/extensionController.php
+++ b/app/Controllers/extensionController.php
@@ -362,7 +362,8 @@ class FreshRSS_extension_Controller extends FreshRSS_ActionController {
 		header("Content-Disposition: inline; filename='{$filename}'");
 		header('Referrer-Policy: same-origin');
 		if (file_exists(DATA_PATH . '/no-cache.txt') || !httpConditional($mtime, cacheSeconds: 604800, cachePrivacy: 2)) {
-			echo $extension->getFile($filename);
+			$contents = $extension->getFile($filename);
+			$this->view->content = is_string($contents) ? $contents : '';
 		}
 	}
 }
diff --git a/app/views/extension/serve.phtml b/app/views/extension/serve.phtml
index e69de29bb..af0b21ea1 100644
--- a/app/views/extension/serve.phtml
+++ b/app/views/extension/serve.phtml
@@ -0,0 +1,4 @@
+<?php
+declare(strict_types=1);
+/** @var FreshRSS_View $this */
+echo $this->content;