L2CPBG

Related to forum post FritzBox Interne Nummern im CARDDAV

Fritz!Box internal numbers get prefixed with "**".
In addition it's possible to list multiple extensions by "#" character, like "**612#613#614" (like a call group).
Contact entries like this will result in a "Failed parsing phone number" error because the number is longer than <maxintlength> and thus get parsed by libphonenumber (which triggers the error).

Unfortunately there seem to exist valid number formats with a "*".

Change behavior in this way, that the libphonenumber error get only thrown if the number is not prefixed with a single "*" character.
Yes, a single "*", because this would also solve issues where a contact has a number with a Fritz!Box line selection (which get prefixed with a single "*" character).