Arabic characters not supported in window/tab titles

[yousufinternet]

Arabic characters in window/tab titles are not showing properly in title bars, changing the font family does not fix this.

herbstluftwm -v:

herbstluftwm 0.9.5
Copyright (c) 2011-2021 Thorsten Wißmann
Released under the Simplified BSD License
xrandr support: on
xinerama support: on

[t-wissmann]

herbstluftwm does not implement a font fallback-mechanism, so you need to set a font that supports the characters that you need. For example, for japanese characters, you can set the font hanamina:pixelsize=17:

For arabic characters, a suitable font settings seems to be Scheherazade New:pixelsize=15 (in arch linux, the package is called ttf-scheherazade-new), and then the window titles show up correctly:

This implies that you need to decide which kind of characters you need (so you can't easily have arabic characters and japanese characters at the same time). Maybe it is possible to combine the fonts to cover all cases you need, but I'm no expert on this.

[yousufinternet]

Thanks for the suggestion, you are correct, I tried DejaVuSans and characters are being displayed, BUT 1- they are in reverse order. 2- they are not connected.
I am not an expert but I think there is a library called HarfBuzz that handles the correct display of this kind of scripts.. because it is very unreadable at its current state.