Landscape printing using Qt print dialog does not correctly re-orient page contents

Hi - several forms of issue with landscape printing have cropped up in KDE applications, each of which seems to result from the content to be printed not being oriented and scaled correctly for landscape page dimensions. Examples include:

"Selecting "landscape" mode in the printer properties (in the "Print" dialog") does nothing except print the image in portrait mode with a third of the image missing." https://bugs.kde.org/show_bug.cgi?id=475937#c0

"Job is printed in portrait orientation, but still cropped for landscape printing, with blank space at the top and bottom of the page(s). If job filled width of a landscape page, sides of job are off the edge of the paper." https://bugs.kde.org/show_bug.cgi?id=503407#c0

These have been reported across multiple distribution bases (Arch, Gentoo, Fedora), and only seem to impact the Qt-provided printing functionality exposed in KDE applications.

Please let me know if this isn't the appropriate component or form to use for reporting - thanks!