[cups] MacOS clients using n-up printing to CUPS server doubles up the n-up option

[Jeff Dyck]

Hopefully someone has some ideas here,

Mostly Apple shop here (education) and we print via IPP Everything / AirPrint through CUPS servers that are advertised via DNS-SD records.  I’ve recently received complaints about the number-up printer option when printing from MacOS…

Basically after some investigation, when a user on MacOS chooses to print say 4 pages per physical piece of paper (number-up=4), MacOS automatically generates a PDF that is already set to 4 pages per page, but then it sends that to the CUPS server with the number-up=4 attribute, so CUPS takes the PDF that already has 4 pages per page and manipulates that to be 4 pages of 4 pages per page, so 16 pages per page total.

Is there some way to configure CUPS to ignore that option?  Or other ideas to make this so it doesn’t stack these options and prints correctly?

I do see in the IPP capabilities that the CUPS queue advertises number-up support, perhaps it’s possible to tweak that?
- number-up-default = 1
- number-up-supported = 1, 2, 4, 6, 9, 16

Thanks in advance,

Jeff