Allow multibyte to be configured (fixes #605)

src/Model/BlogCategory.php

@@ -7,7 +7,6 @@
 /**
  * A blog category for generalising blog posts.
  *
-*
  * @method Blog Blog()
  *
  * @property string $Title
@@ -33,6 +32,8 @@ class BlogCategory extends DataObject implements CategorisationObject
      */
     private static $table_name = 'BlogCategory';
 
+    private static bool $allow_urlsegment_multibyte = true;
+
     /**
      * @var array
      */

src/Model/BlogObject.php

@@ -181,12 +181,7 @@ public function generateURLSegment($increment = 0)
     {
         $increment = (int) $increment;
         $filter = URLSegmentFilter::create();
-
-        // Setting this to on. Because of the UI flow, it would be quite a lot of work
-        // to support turning this off. (ie. the add by title flow would not work).
-        // If this becomes a problem we can approach it then.
-        // @see https://github.com/silverstripe/silverstripe-blog/issues/376
-        $filter->setAllowMultibyte(true);
+        $filter->setAllowMultibyte($this->config()->get('allow_urlsegment_multibyte') ?? true);
 
         $this->URLSegment = $filter->filter($this->Title);
 

src/Model/BlogTag.php

@@ -18,6 +18,8 @@ class BlogTag extends DataObject implements CategorisationObject
 {
     use BlogObject;
 
+    private static bool $allow_urlsegment_multibyte = true;
+
     /**
      * Use an exception code so that attempted writes can continue on
      * duplicate errors.