Issue broken supply level reports in IPP

[tillkamppeter]

See

https://invent.kde.org/plasma/print-manager/-/merge_requests/311

Here a printer reports a broken supply level report in its IPP get-printer-attributes response. The report consists of araays where each array is supposed to have one element for each supply, so if the printer has n supplies each array has n elements. In the example in the linked bug report, there is a black and a color cartridge (cheap inkjet, 2 supplies), but the marker-levels attribute has 8 elements.

[alexpevzner]

I haven't quite understood, how is it related to go-mfp

Looks like CUPS should sanitize marker levels, not just mirror these attributes from the printer...

[tillkamppeter]

And as CUPS passes on supply levels only after having printed one job I recommend to desktop/GUI developers to poll supply levels directly from the printer, so having the simulation reporting supply levels and also issuing broken reports makes all sense. And this does not only test the GUI app whether it can cope with firmware bugs but also any sanitizing done by CUPS.