From d46dba32d4cd4ef763a635ab5dca41785364f3f8 Mon Sep 17 00:00:00 2001
From: Brendan Heywood <brendan@catalyst-au.net>
Date: Mon, 21 Oct 2019 19:46:26 +1100
Subject: [PATCH] MDL-65693 files: Honor http HEAD requests for files

---
 lib/filelib.php | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/filelib.php b/lib/filelib.php
index 36a85d87561..3dcebbf5f74 100644
--- a/lib/filelib.php
+++ b/lib/filelib.php
@@ -2229,6 +2229,10 @@ function readfile_accel($file, $mimetype, $accelerate) {
 
     header('Content-Length: '.$filesize);
 
+    if (!empty($_SERVER['REQUEST_METHOD']) and $_SERVER['REQUEST_METHOD'] === 'HEAD') {
+        exit;
+    }
+
     if ($filesize > 10000000) {
         // for large files try to flush and close all buffers to conserve memory
         while(@ob_get_level()) {