[okular] [Bug 497746] New: Okular overrides CUPS printer settings making it impossible to print in B/W

[Sergio]

https://bugs.kde.org/show_bug.cgi?id=497746

            Bug ID: 497746
           Summary: Okular overrides CUPS printer settings making it
                    impossible to print in B/W
    Classification: Applications
           Product: okular
           Version: 24.08.3
          Platform: Manjaro
                OS: Linux
            Status: REPORTED
          Severity: normal
          Priority: NOR
         Component: printing
          Assignee: okular-devel at kde.org
          Reporter: sergio.callegari at gmail.com
  Target Milestone: ---

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SUMMARY

Okular appears to *override* the CUPS printer settings, forcing the printer to
print in color even if it is configured to print in black and white.

I have an HP printer and I am using the HPLIP printer driver for it. The driver
has an option "Print color as Gray". I set it by default to YES. When I open a
PDF document using color in Okular and I try to print it, I see no okular
option to select Grayscale or Color printing (there used to be one under
"options" long time ago). However, I can go to the advanced printer settings
and verify there that "Print Color as Gray is ticked". However, Okular appears
to override it and prints in color.

The issue appears to be with Okular, not with CUPS or the printer drivers. If I
print from other applications, then I can print in grayscale. Most notably, If
I open the same PDF document with another PDF viewer (e.g., the last free
version of masterpdfeditor), and I print, the printout comes in grayscale (note
that masterpdfeditor has a tick to force the grayscale printing, but if the
"advanced printer options" are ste to "Print Color as Gray", then this
application prints in grayscale even when the tick to force grayscale printing
from the application is not selected).

This issue is very bad. I have left priority as normal, but please consider
raising it. On many printers the cost of color printing is 4-12 times the cost
of printing in black and white.

STEPS TO REPRODUCE
1. Open a PDF document including colored elements
2. Open the print dialog
3. Assure that in the advanced printer options everything is configured to
print in grayscale

OBSERVED RESULT

Okular still prints in color

EXPECTED RESULT

Okular should print in grayscale when the printer is configured to print in
grayscale

SOFTWARE/OS VERSIONS

Operating System: Manjaro Linux 
KDE Plasma Version: 6.2.4
KDE Frameworks Version: 6.8.0
Qt Version: 6.8.1
Kernel Version: 6.6.65-1-MANJARO (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-4750HQ CPU @ 2.00GHz
Memory: 15.5 GiB of RAM
Graphics Processor: Mesa Intel® Iris® Pro Graphics P5200
Manufacturer: Notebook
Product Name: W740SU


ADDITIONAL INFORMATION

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