Ticket #15407: 15407.diff

wp-includes/category-template.php

@@ -64 +64 @@
  * @return array
  */
 function get_the_category( $id = false ) {
-        $categories = get_the_terms( $id, 'category' );
+        $categories = (array) get_the_terms( $id, 'category' );
 
-        foreach ( array_keys( (array) $categories ) as $key ) {
-                _make_cat_compat( $categories[$key] );
+        if ( $categories ) {
+                foreach ( array_keys( $categories ) as $key ) {
+                        _make_cat_compat( $categories[$key] );
+                }
         }
+
         // Filter name is plural because we are return alot of categories not just one
         return apply_filters( 'get_the_categories', $categories );
 }