defect
(User-visible)
In some cases, when multiple files are uploaded and the ProgressDialog opens, it closes but a gray overlay remains. After reloading the page, the overlay disappears and the upload was successful.
The FolderControl receives a ClientAction that calls ` DragAndDropFile.hideProgressDialog ` on the client side as soon as the upload is complete. However, it appears that the `controlId` changes from time to time. This causes the ` DragAndDropFile.hideProgressDialog ` function to abort because it finds nothing with `document.getElementById(controlId) ` and then throws a `NullPointerException`. Since hideProgressDialog first removes the progressDialog and then the gray background, the latter is no longer executed due to the error, even though it does not depend on the controller.
Improvement
In ` DragAndDropFile.hideProgressDialog `, the code now checks whether `document.getElementById(controlId) ` returns `null`. If so, the function is terminated. To still remove the gray overlay, it is removed before the check instead of after it, as was originally the case.
Test
No test.