Fix deleting last element from saved folder + Fix displaying empty saved folder

src/Model/FileTag.php

@@ -290,7 +290,7 @@ class FileTag
             return false;
         }
 
-        $fields = ['file' => str_replace($pattern, '', $item['file'])];
+        $fields = ['file' => str_replace($pattern, null, $item['file'])];
         Item::update($fields, ['id' => $item_id]);
 
         $r = q("SELECT `oid` FROM `term` WHERE `term` = '%s' AND `otype` = %d AND `type` = %d AND `uid` = %d",

src/Model/Item.php

@@ -911,7 +911,7 @@ class Item extends BaseObject
 				}
 			}
 
-			if (!empty($files)) {
+			if (!is_null($files)) {
 				Term::insertFromFileFieldByItemId($item['id'], $files);
 				if (!empty($item['file'])) {
 					DBA::update('item', ['file' => ''], ['id' => $item['id']]);