I use slovak language in KDE 4.9.5 and all numbers are shown as Arabic-Indic. Settings in systemsettings shows Arabic numbers but it doesn't work. Also all qt application shows Arabic-Indic (e.g. Skype). It's unreadable for me. Reproducible: Always
If pure Qt applications show the same bug, this is no KDE bug.
https://bugreports.qt-project.org/browse/QTBUG-28843
Thanks for the update, marking correctly.