Adding book via ISBN search: Preserve inputs

[ChristianGruen]

When I add a book via the ISBN, a form is shown in which the obtained data can be completed. When I edit something, when I open a dialog (e.g. for editing the description or for adding new authors), and when I return to the form, my intermediate edits get lost.

The problem does not occur when I save the entry and edit it in a second step, or when I create a new book via the menu item “Add Manually”.