🚑 Item: set id to null in clone function

This is done to set the id to null BEFORE resetting the updated fields.
The purpose of this is to avoid explicitly adding a NULL id into the DB,
which provokes an error in some DBMS (like postgres).

Fixes #1375

lib/Db/Item.php

@@ -99,6 +99,13 @@ public function __construct()
 
     public function __clone()
     {
+        $this->setId(null);
+
+        /**
+         * Removes 'id' from updatedFields; this will avoid explicitly
+         * inserting the value NULL into the DB, and will instead allow a new
+         * id to be generated.
+         * */
         $this->resetUpdatedFields();
         $this->markFieldUpdated('contentHash');
         $this->markFieldUpdated('guidHash');

lib/Service/ShareService.php

@@ -110,7 +110,6 @@ public function shareItemWithUser(string $userId, int $itemId, string $shareReci
 
         // Duplicate item & initialize fields
         $sharedItem = clone $item;
-        $sharedItem->setId(null);
         $sharedItem->setUnread(true);
         $sharedItem->setStarred(false);
         $sharedItem->setSharedBy($userId);