deleting thumbnails

[Jens Finke]

Olivier wrote:
> <title>Re-creating a thumbnail</title>
> 
> <para>
> If a program re-creates a thumbnail because the existing thumbnail does
> not have the correct size, it should keep the original thumbnail, and
> add the new thumbnail to the correct directory for its configured size.
> </para>
> 
> <para>
> If the user requests the thumbnail to be re-created, there is no way for
> the program to find out why it has to re-create it. The program should, 
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^
What does this mean? A program has all information at hand to decide if a 
thumbnail is valid or not and if it exists in the desired size. Or do I overlook 
a special case?

> therefore, delete all sizes of thumbnails for that image, and create
> only the thumbnail for its configured size.
> </para>

Regards,

  Jens