Re: bluetooth DUN silently discarding "invalid" APNs

[Marc Herbert <Marc Herbert gmail com>]

>> You should simply just stay clear of this whole mess and not validate
>> anything. This would add two new and incredibly great features:
>>
>> - Restore an error message in case of a typo (as opposed to silently
>>   discarding user input)
>> - Support APNs with unusual characters.
>>
>> Two new features by merely deleting some code, how great value is that?
> 
> The code was put into NM in the first place to ensure that characters
> like spaces and such that certainly *aren't* allowed in APNs weren't
> used.  The validation is still necessary, but I think the core problem
> we should fix is ensuring that you can't type invalid characters into
> the box and you can't type an invalid APN length.  Then we should extend
> the allowed characters.  We certainly shouldn't remove the checks
> completely, since there *are* actually restrictions on the APN contents
> and length.

Besides the "hostname" legacy, please tell where do these "certainly
not allowed" characters come from. My Nokia phone lets me input any
character crap in the APN field without even a warning. Then I just
get the same "Connection failed, check your settings" error message
than for any other "valid" typo  (reminder: Nokia and Ericsson
designed and implemented GSM, UMTS & LTE practically alone). wvdial
lets me enter the same crap. So why is NetworkManager implementing
this? Too much spare time?

But once again, the core problem is not abusive validation. The core
problem is silently discarding user input with a misleading
"configuration completed" message. This needs an quick fix that cannot
wait the redesign of a better user interface. And surprise, there is a
really obvious quick fix: just behave like Nokia.