Cellphone required does not require valid phone number

[Laaknor]

Tested with userinfo_cellphone_required activated, could register with the cellphone number "hei". Should be only numbers, without spaces or +.

[hultberg]

Only norwegian phone numbers? We could use the following regex to check the string: /^(\+?[0-9]{1,2})?[0-9]{8,}$/. It would at least match a norwegian number, and a minimum of 8 length in the number. It would not really respect foreign lengths based on the country code, but its a simple check.

Demo & test: https://3v4l.org/rQ8kk