From a925bb10cd49bec4949a6f9575d83148513ef0f5 Mon Sep 17 00:00:00 2001
From: Ammarpad <ammarpad@yahoo.com>
Date: Fri, 1 Nov 2024 12:31:12 +0100
Subject: [PATCH] Fix handling of self-closing tag

self closing tag <categorytree/> is invalid, but where encountered
the content of the tag is null.

Convert the null to empty string since CategoryTree::getTag require one

Bug: T378765
Change-Id: Iede4499952295b75a19bd05a5963caab00a9cadd
---
 includes/Hooks.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/includes/Hooks.php b/includes/Hooks.php
index 805ccf4a..242bbd2c 100644
--- a/includes/Hooks.php
+++ b/includes/Hooks.php
@@ -231,7 +231,7 @@ class Hooks implements
 		}
 
 		return $message .
-			$ct->getTag( $cat, $hideroot, $attr, $depth );
+			$ct->getTag( $cat ?? '', $hideroot, $attr, $depth );
 	}
 
 	/**