[BUG] "Delete media and file" deletes three items, including the generic thumbnail.

[rosiel]

What steps does it take to reproduce the issue?

• Log in as admin.

• Create a number of non-image media. Note that they have the default thumbnail, generic.png.

• For good measure create an image media too, with an image file.

• Select one non-image media from the Media list, and select the Action "Delete media and files".

• See the message, "Deleted 3 items." (this should read "Deleted 2 items!)

• Note that all the other non-image media that used to display in the media list with a default thumbnail, now have none!

• Delete the image media using "Delete media and files."

• Note that the message also says "Deleted 3 items." (though this is less destructive to other media, this is still what's causing our tests to fail).

• When does this issue occur?

Whenever you use "Delete media and files"

• Which page does it occur on?

The Media view or wherever you can apply actions to media.

• What happens?

The thumbnail is getting deleted and maybe(??) shouldn't.

• To whom does it occur (anonymous visitor, editor, administrator)?

Anyone with permission to delete media via an action.

• What did you expect to happen?

The default thumbnail should not get deleted, and the output should always be "Deleted 2 items" (unless you've added other files to other fields on the media).

Which version of Islandora are you using?

Modern on Drupal 9.5.10.

Any related open or closed issues to this bug report?

Screenshots:

[rosiel]

Addressed by #960