From 784945d6379a5685cde7334732d0579dc1d9fc2d Mon Sep 17 00:00:00 2001
From: Alexander Ebert <ebert@woltlab.com>
Date: Tue, 18 Jul 2023 12:04:30 +0200
Subject: [PATCH] Provide a sane width attribute for attachments

---
 .../files/lib/system/bbcode/AttachmentBBCode.class.php       | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/wcfsetup/install/files/lib/system/bbcode/AttachmentBBCode.class.php b/wcfsetup/install/files/lib/system/bbcode/AttachmentBBCode.class.php
index 149d82c9ef..82188dfb75 100644
--- a/wcfsetup/install/files/lib/system/bbcode/AttachmentBBCode.class.php
+++ b/wcfsetup/install/files/lib/system/bbcode/AttachmentBBCode.class.php
@@ -65,7 +65,10 @@ final class AttachmentBBCode extends AbstractBBCode
     {
         $alignment = $attributes[1] ?? '';
         $thumbnail = $this->renderImageAsThumbnail($attachment, $outputType, $attributes[2] ?? false);
-        $width = $attributes[3] ?? '100%';
+        $width = $attributes[3] ?? '';
+        if (!\preg_match('~^(?:100%|\d{2}(?:\.\d{2})?%)$~', $width)) {
+            $width = '100%';
+        }
 
 
         if ($thumbnail) {
-- 
2.20.1