Compare string with German umlauts

[Martin Tschierschke]

On Monday, 18 May 2020 at 14:28:33 UTC, Steven Schveighoffer 
wrote:
>
> What you need is to normalize the data for comparison: 
> https://dlang.org/phobos/std_uni.html#normalize
>
> For more reference: 
> https://en.wikipedia.org/wiki/Combining_character
>
> -Steve

I checked it again but could not reproduce the original error, it 
somehow seems that my compare string contained another error. But 
nevertheless good to know how to deal with encoding errors!