Cleanup

src/endpoints/permissions/set.rs

@@ -26,6 +26,14 @@ pub async fn set(
         .handle_internal()?
         .can_manage_guard()?;
 
+    let folder_info = db::folder::get_by_id(params.folder_id, &pool)
+        .await
+        .handle_internal()?
+        .ok_or(StatusCode::NOT_FOUND)?;
+    if folder_info.owner_id == params.user_id {
+        return Err(StatusCode::BAD_REQUEST);
+    }
+
     db::permissions::insert(
         params.user_id,
         params.folder_id,