FIX Apply raw2xml before extension hook

src/ORM/Hierarchy/Hierarchy.php

@@ -808,8 +808,9 @@ public function getTreeTitle(): string
     {
         $owner = $this->getOwner();
         $title = $owner->MenuTitle ?: $owner->Title;
+        $title = Convert::raw2xml($title ?? '');
         $owner->extend('updateTreeTitle', $title);
-        return Convert::raw2xml($title ?? '');
+        return $title;
     }
 
     /**

tests/php/ORM/HierarchyTest.php

@@ -9,6 +9,8 @@
 use SilverStripe\Versioned\Versioned;
 use SilverStripe\Dev\SapphireTest;
 use SilverStripe\ORM\Hierarchy\Hierarchy;
+use SilverStripe\Security\Group;
+use SilverStripe\ORM\Tests\HierarchyTest\TestTreeTitleExtension;
 
 class HierarchyTest extends SapphireTest
 {
@@ -682,4 +684,15 @@ public function testDefaultParent(string $class, ?string $defaultParentConfig, ?
 
         $this->assertSame($expected, $obj->defaultParent());
     }
+
+    /**
+     * Tests that HTML added by an extension is not escaped
+     */
+    public function testGetTreeTitleExtension()
+    {
+        Group::add_extension(TestTreeTitleExtension::class);
+        $group = new Group();
+        $group->Title = 'My group';
+        $this->assertSame('<i>My group</i>', $group->getTreeTitle());
+    }
 }

tests/php/ORM/HierarchyTest/TestTreeTitleExtension.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace SilverStripe\ORM\Tests\HierarchyTest;
+
+use SilverStripe\Dev\TestOnly;
+use SilverStripe\Core\Extension;
+
+class TestTreeTitleExtension extends Extension implements TestOnly
+{
+    protected function updateTreeTitle(string &$title)
+    {
+        $title = "<i>$title</i>";
+    }
+}