From 930c7cb94c7957a8572bdbdef2ad5d113d99da9e Mon Sep 17 00:00:00 2001
From: Daniel Jagszent <daniel@jagszent.de>
Date: Tue, 14 Dec 2021 17:00:44 +0100
Subject: [PATCH] Update matomo.js check

Only HTTP/2 server use lowercase HTTP headers. Use capitalised header names for HTTP/1 support

Content Types like `application/javascript; charset=utf-8` should not trigger a warning.

Matomo's HTTP::sendHttpRequest does not send the required `Accept-Encoding` header. Standards compliant HTTP servers cannot send compressed output in this case. This change does the compression check by checking for the existence of the correct `Vary` header. Standards-compliant HTTP servers should send it when compression is possible.
---
 Diagnostic/MatomoJsCheck.php | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/Diagnostic/MatomoJsCheck.php b/Diagnostic/MatomoJsCheck.php
index 0630467..ff42f24 100644
--- a/Diagnostic/MatomoJsCheck.php
+++ b/Diagnostic/MatomoJsCheck.php
@@ -68,8 +68,8 @@ class MatomoJsCheck implements Diagnostic
             if (
                 $status != 200
                 || strpos($data, "c80d50af7d3db9be66a4d0a86db0286e4fd33292") === false
-                || empty($headers["content-type"])
-                || empty($headers["content-encoding"])
+                || empty($headers["Content-Type"])
+                || empty($headers["Vary"])
             ) {
                 $result = new DiagnosticResult($this->label);
                 $result->addItem(new DiagnosticResultItem(
@@ -82,8 +82,8 @@ class MatomoJsCheck implements Diagnostic
                 return [$result];
             }
             $results = new DiagnosticResult($this->label);
-            $contentType = $headers["content-type"];
-            if ($contentType !== "application/javascript") {
+            $contentType = $headers["Content-Type"];
+            if (strpos($contentType, "application/javascript") !== 0) {
                 $results->addItem(new DiagnosticResultItem(
                     DiagnosticResult::STATUS_WARNING,
                     Piwik::translate("DiagnosticsExtended_MatomoJSCheckMIMEError",
@@ -91,8 +91,8 @@ class MatomoJsCheck implements Diagnostic
                 ));
 
             }
-            $contentEncoding = $headers["content-encoding"];
-            if ($contentEncoding === "gzip" || $contentEncoding === "br") {
+            $vary = strtolower($headers["Vary"]);
+            if (strpos($vary, 'accept-encoding') !== false) {
                 $results->addItem(new DiagnosticResultItem(
                     DiagnosticResult::STATUS_OK,
                     Piwik::translate("DiagnosticsExtended_MatomoJSCheckGzipped")