Upgrade to 3.9.0

kirby/src/Cms/PageActions.php

@@ -223,7 +223,7 @@ trait PageActions
 			throw new InvalidArgumentException('Use the changeSlug method to change the slug for the default language');
 		}
 
-		$arguments = ['page' => $this, 'slug' => $slug, 'languageCode' => $languageCode];
+		$arguments = ['page' => $this, 'slug' => $slug, 'languageCode' => $language->code()];
 		return $this->commit('changeSlug', $arguments, function ($page, $slug, $languageCode) {
 			// remove the slug if it's the same as the folder name
 			if ($slug === $page->uid()) {
@@ -620,9 +620,7 @@ trait PageActions
 					->count();
 
 				// default positioning at the end
-				if ($num === null) {
-					$num = $max;
-				}
+				$num ??= $max;
 
 				// avoid zeros or negative numbers
 				if ($num < 1) {