X-Git-Url: http://aleph1.co.uk/gitweb/?a=blobdiff_plain;f=web%2Fcore%2Flib%2FDrupal%2FCore%2FAsset%2FLibraryDependencyResolver.php;h=b84b8fac9ef739d167b0d2ea5fe51cebadd44f7a;hb=refs%2Fheads%2Fd864;hp=95fca186614fc944976b059e7083913acafb73ec;hpb=a2bd1bf0c2c1f1a17d188f4dc0726a45494cefae;p=yaffs-website

diff --git a/web/core/lib/Drupal/Core/Asset/LibraryDependencyResolver.php b/web/core/lib/Drupal/Core/Asset/LibraryDependencyResolver.php
index 95fca1866..b84b8fac9 100644
--- a/web/core/lib/Drupal/Core/Asset/LibraryDependencyResolver.php
+++ b/web/core/lib/Drupal/Core/Asset/LibraryDependencyResolver.php
@@ -65,6 +65,8 @@ class LibraryDependencyResolver implements LibraryDependencyResolverInterface {
    * {@inheritdoc}
    */
   public function getMinimalRepresentativeSubset(array $libraries) {
+    assert(count($libraries) === count(array_unique($libraries)), '$libraries can\'t contain duplicate items.');
+
     $minimal = [];
 
     // Determine each library's dependencies.