For KF5-based builds this is resolved because the improved heuristic for detecting light high-contrast themes (like "Desert") is used for VSD 3.3 and Gpg4win 4.4.

For simplicity (and because I think entering tab characters isn't really essential for the notepad) I decided to go with the first solution.

Can't you just use file descriptors everywhere and use _get_osfhandle once you need a HANDLE. That is what I am used to seeing in Windows code in Gnulib (although I do not touch it much).

Regarding 64bit handles https://learn.microsoft.com/en-us/windows/win32/winprog64/interprocess-communication
tells us:

Ready for testing.

and for certification revocation (and some other places): https://invent.kde.org/pim/libkleo/-/merge_requests/197

For card stuff: https://invent.kde.org/pim/kleopatra/-/merge_requests/400

For the tooltips: https://invent.kde.org/pim/libkleo/-/merge_requests/196

This seems to be a good opportunity to replace paperkey with a new tool to take advantage of the smaller ECC keys which allow us to re-generate most stuff.

Ok, it was a missing update (although windows claimed to be up-to-date).
After installing 2025-06 [...] KB5060829 the Microsoft Print to PDF feature is available again and printing also works in Kleopatra/Okular.

A second patch fixes the problem with the button in the smart card view.

I have added a patch to disable recoloring of the status icons in Gpg4win. This ensures that the status icons in the selected rows don't get all-white.

Upstream bug report for invisible status icons: https://bugs.kde.org/show_bug.cgi?id=506434 (Icon coloring is inherently incompatible with colored Breeze status icons)

It's also the same error in Okular, when a pdf is printed.

Same on gpg4win-4.4.1 @ win11 (here a bit more debugview context)

3	3.503991	8584	kleopatra.exe	org.kde.pim.kleopatra: Paperkey export finished:  0 status:  QProcess::NormalExit
4	3.691599	8584	kleopatra.exe	QPrintDialog: Cannot be used on non-native printers
5	3.691981	8584	kleopatra.exe	QPrintDialog: Cannot be used on non-native printers
6	3.692752	8584	kleopatra.exe	org.kde.pim.kleopatra: Printing aborted.

Works fine here.

version

C:\Users\g10\Desktop\tmp\scdecrypt>gpg --version
gpg (GnuPG) 2.5.8
libgcrypt 1.11.1
Copyright (C) 2025 g10 Code GmbH
License GNU GPL-3.0-or-later <https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

gpg --version?
gpg -K?

You're right, it also errors on gpg directly:

I can't reproduce. Please check whether this works if you use gpg directly; it's a bit unlikely that this is kleopatra-specific, since kleopatra doesn't really care whether the key is on a smartcard or not.

a: expired certificate