Global setting of hyphenation for words containing dashes

Question

I'm using the word "Zwei-Drittel-Abstimmungsmehrheit" a bunch of times in my document. Often it won't fit into the current line, extending into the right margin.

I figured out that the following package helps :

\usepackage[shortcuts]{extdash} 

Then I can write

Zwei\-/-Drittel\-/Abstimmungs\-mehrheit

and the hyphenation is done correctly.

Is there a way that I can set this hyphenation globally for this word? Like i can do it with the command

\hyphenation{...}

Sadly this command doesn't work for words containing dashes.

Answer 1

In the question Adequate hyphenation of words already containing a hyphen, I was looking for a fully automatic solution (i.e., without special shorthands in the document body and without using \hyphenation or similar commands) to disregard break points less than four characters before and after existing hyphens. From Stephan Henning's answer I learned that at least a solution with \hyphenation is available if you're willing to switch to Lua(La)TeX. Compile the following example with LuaLaTeX:

\documentclass{article}

\usepackage[ngerman]{babel}

\hyphenation{Zwei=Drittel=Abstimmungs-mehr-heit}

\textwidth=120pt% just for the example

\begin{document}

Zwei-Drittel-Abstimmungsmehrheit

\end{document}