cups ppi parameter should be a string

[Kenneth Fazzone]

cups encode.c treats parameter ppi as an integer, but it should be a string.

the image filter drivers expect the form ppi=300x600
to specify source image dpi for images where it is asymmetric.

I encountered this issue trying to print full-sized images without scaling on a dymo 450 label printer.
This bug causes images to print across 2 labels when trying to use the 300x600dpi graphics mode.

This should print a single label:
lpr -o ppi=300x600 -o scaling=0 -o PageSize=w167h288 -o PageRegion=w167h288 -o Resolution=300x600dpi -o DymoHalftoning=Default -o DymoPrintDensity=Medium -o DymoPrintQuality=Graphics -o MediaDimensions=w167h288 ~/Desktop/test_Graphics_portrait.png

where the png is a 664*2224 image without any dpi metadata.
Instead the ppi option gets sanitized to 300, and the image gets printed across 2 labels.

Description: Ubuntu 20.04.2 LTS
Release: 20.04

cups:
  Installed: 2.3.1-9ubuntu1.1
  Candidate: 2.3.1-9ubuntu1.1
  Version table:
 *** 2.3.1-9ubuntu1.1 500
        500 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
        500 http://archive.ubuntu.com/ubuntu focal-security/main amd64 Packages
        100 /var/lib/dpkg/status
     2.3.1-9ubuntu1 500
        500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages

[Kenneth Fazzone (kfazz01)]

this patch lets the ppi setting be a string

[Till Kamppeter (till-kamppeter)]

Please report this upstream on

https://github.com/OpenPrinting/cups

as this is not only concerning Ubuntu, but any OS which uses CUPS.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "cups_ppi_patch" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

[Kenneth Fazzone (kfazz01)]

i've reported this upstream, the github issue is:
https://github.com/OpenPrinting/cups/issues/115

[Till Kamppeter (till-kamppeter)]

Thank you very much.

[Kenneth Fazzone (kfazz01)]

Status in upstream github is closed wontfix.
The reason is that ppi is defined as an integer, and the cups-filters usage is broken.

Reported the issue to cups-filters at https://github.com/OpenPrinting/cups-filters/issues/347

[Till Kamppeter (till-kamppeter)]

Fix in cups-filters should already be in Ubuntu. Closing ...