[cups] No duplex on Konica C364

[Helge Blischke]

> Am 09.10.2019 um 19:12 schrieb Bob Burton <bobburton at math.arizona.edu>:
> 
> I still don't have this working from any of the system or application GUI
> print menus, but it does work fine from the command line, e.g.:
> 
> lp -d KM-401 -o sides=two-sided-long-edge -o page-ranges=1-2 my_file.pdf
> 
> So it may not be a print driver or cups problem, maybe just something
> squirrelly in system-config-printer?
> 
> Bob
> 

A little bit of research in the cups sources (2.2.1 in this case) revealed:

–	When interpreting the duplex options, CUPS looks for some vendor specific variants
	which do not conform to the Adobe conventions; in case of Konica:
	*KMDuplex 2Sided
	instead of the default
	*Duplex DuplexNoTumble

	These variants are not checked by CUPS (others are, e.g. those used by EFI rips)

–	When using the IPP options, these are translated to the PPD keywords and values
	conforming to the Adobe standard and then used without querying the real PPD file.

	That is why the sides option works.

I do not know what system-config-printer does with those weird options.

Helge