Bug 468634

SUMMARY
Okular defaults to printing on letter sized paper.
PDF pages are A4
$LC_ALL is de_DE.UTF-8 (and DIN A4 is literally a German industry standard size)
$LC_PAPER is de_DE.UTF-8 (dito)
CUPS printer default is A4
Last document was printed in A4
Actual paper size in the printer is A4
And yet okular still defaults to letter size. every. single. time.


STEPS TO REPRODUCE
1. Open PDF
2. Ctrl P
3. Check printer settings
4. Be annoyed about "Letter" being chosen as default paper size, change it to A4

OBSERVED RESULT
Printing A4 documents as letter on A4 paper yields strange page margins, so these steps are necessary for each and every printed document

EXPECTED RESULT
Steps 3+4 become obsolete since A4 (or any other format you'd prefer) can be set as default or is even chosen as default by using other means such as CUPS default paper settings of the printer used or PDF page size

SOFTWARE/OS VERSIONS
Betriebssystem: Kubuntu 22.04
KDE-Plasma-Version: 5.24.7
KDE-Frameworks-Version: 5.92.0
Qt-Version: 5.15.3
Kernel-Version: 5.15.0-56-generic (64-bit)
Grafik-Plattform: X11

ADDITIONAL INFORMATION
Maybe a regression of #174354 - maybe not. Other non-KDE applications default to A4 as they should (e.g. Firefox, Thunderbird, Chrome, Opera)