From bd55096bbadafbd17a1c2c035345096cea93d8e5 Mon Sep 17 00:00:00 2001
From: joshuaruesweg <ruesweg@woltlab.com>
Date: Thu, 4 Mar 2021 17:03:41 +0100
Subject: [PATCH] Propper handle libxml errors

---
 .../message/unfurl/UnfurlResponse.class.php     | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/wcfsetup/install/files/lib/system/message/unfurl/UnfurlResponse.class.php b/wcfsetup/install/files/lib/system/message/unfurl/UnfurlResponse.class.php
index d26bbe21b5..7fdaa5908f 100644
--- a/wcfsetup/install/files/lib/system/message/unfurl/UnfurlResponse.class.php
+++ b/wcfsetup/install/files/lib/system/message/unfurl/UnfurlResponse.class.php
@@ -187,10 +187,19 @@ final class UnfurlResponse
      */
     private function readDomDocument(): void
     {
-        \libxml_use_internal_errors(true);
-        $this->domDocument = new \DOMDocument();
-        if (!$this->domDocument->loadHTML('<?xml version="1.0" encoding="UTF-8"?>' . $this->body)) {
-            throw new ParsingFailed("Could not parse body.");
+        $useInternalErrors = \libxml_use_internal_errors(true);
+        \libxml_clear_errors();
+        try {
+            $this->domDocument = new \DOMDocument();
+            if (!$this->domDocument->loadHTML('<?xml version="1.0" encoding="UTF-8"?>' . $this->body)) {
+                throw new ParsingFailed("DOMDocument::loadHTML() failed");
+            }
+            foreach (\libxml_get_errors() as $error) {
+                throw new ParsingFailed("libxml error: {$error->message}.", $error->code);
+            }
+        } finally {
+            \libxml_use_internal_errors($useInternalErrors);
+            \libxml_clear_errors();
         }
     }
 
-- 
2.20.1