ok, thx

I guess this can be closed then?

This determines if a user can download the original image file (the 
full-size file that was originally uploaded) instead of the resized 
image that is used in the image view. This is different then allowing 
zip downloads. Creating, and then transferring, a zip file that could 
conceivably contain *every* image in the gallery is not a good thing 
to allow the world to do.

i think this is already there, in the gallery settings, You have the setting
'Who should be able to download (original) photos':
- everybody
- logged in users
- users with read permissions
(backtranslated from german :-)
i thought the permission check in download checks then this setting

Changes have been made in Git for this ticket:

MFB: Don't show download as zip link if we can't actually do it.
Bug: 9178

http://git.horde.org/diff.php/ansel/lib/View/GalleryRenderer/Gallery.php?rt=horde-git&r1=a0662bb9e501771ae1fdb966f7331dedd19b5ece&r2=5f3efa958b10d85e88e4395374b3c6ebdf188bc0

Changes have been made in CVS for this ticket:

Don't show the download images as zip link if we can't actually do it.
Bug: 9178
http://cvs.horde.org/diff.php/ansel/lib/Views/GalleryRenderers/Gallery.php?rt=horde&r1=1.29&r2=1.30&ty=u
http://cvs.horde.org/diff.php/ansel/lib/Views/Image.php?rt=horde&r1=1.86&r2=1.87&ty=u

The idea is to prevent downloading of zip files by guests in order to 
prevent potential DOS attacks. Generating and downloading the zip 
files is very resource intensive, and for large galleries, having the 
world be able to do this is probably not a Good Idea.

I'd be willing to make this an additional permission on Ansel, so it 
has to be explicitly allowed. "Allow guests to download zip files" or 
something similar.

when trying to download a gallery or selected Photos as a zip file,
the Access denied message appears when You are not logged in (guest),
even when guests have read permission.

the attached patch corrects that by removing the superfluous
!Auth::getAuth()
from image.php and gallery.php