Qt4 applications show wrong number format, making them unusable

In Qt4 applications (Scribus Clementine preferences, Qt configuration) the number format is wrong when the locale is ku_TR (Kurdish in Turkey). This makes Qt applications unusable as soon as numbers are involved.

An example:
I am using Scribus 1.4.2 on Ubuntu Gnome 14.04 with the locale ku_TR, which uses roman script, and arabic numbers like 123456789.

All numbers in Scribus are displayed in Arabic-Indic numerals like ٠١٢٣٤٥٦٧٨٩ . For people who are not used to these numerals, Scribus becomes practically unusable.

This is independent from the user interface language of Scribus.

The exact same problem is valid for Debian Jessie.