This change breaks CI, see https://build.kde.org/view/Frameworks%20kf5-qt5/job/kio%20master%20kf5-qt5/351/PLATFORM=Linux,compiler=gcc/testReport/(root)/TestSuite/kiocore_kfileitemtest/

Can't reproduce locally. Could it be that XDG dirs aren't properly setup on CI or something like that?

No XDG is well set up since everything else passes ;)

Actually I have the same error locally. Where does the string "folder-videos" come from?

That's in kioglobal_p.cpp mapped from MoviesLocation, so KIO::fileNameForUrl should return that.

It's also tested for in testIconNameForStandardPath (though here it's just $HOME + /Videos)

Ah I see.

The problem is that /home/dfaure/Videos (i.e. what is returned by QSP) does NOT exist (I guess I deleted it, can't remember).

I don't see anyone (neither iconNameForUrl nor iconForStandardPath) checking for existance, though, it would/should always return videos icon for a folder that potentially be in StandardPaths?

OK, not sure what happened, but something changed ~/.config/user-dirs.dirs and here's what happens now:

~/.config/user-dirs.dirs says
XDG_VIDEOS_DIR="$HOME/"
which leads to MoviesLocation returning /home/dfaure, so the code in iconForStandardPath() matches the home folder first and returns "user-home".

QDEBUG : KFileItemTest::testIconNameForUrl(videos) KFileItemTest::testIconNameForUrl: QUrl("file:///home/dfaure")
FAIL! : KFileItemTest::testIconNameForUrl(videos) Compared values are not the same

Actual   (KIO::iconNameForUrl(url)): "user-home"
Expected (expectedIcon)            : "folder-videos"

... and when it's actually set to /home/dfaure/Videos, then KIO::iconNameForUrl skips the call to KIOPrivate::iconForStandardPath because of the mt.inherits(QLatin1String("inode/directory") check.
The mimetype is application/octet-stream (default mimetype) if the dir doesn't exist.

I'll commit a fix for both cases (equal to home and non-existent).