[Pkg-shadow-devel] [shadow-maint/shadow] Allow dots (`.`) in user/group names (#34)

[Serge E. Hallyn]

Quoting Alec Larsen (notifications at github.com):
> Is there a technical reason why dots (`.`) are not allowed in user/group names?
> 
> And if not, would a PR to allow them be accepted? It seems like a simple enough change to [`is_valid_name` in libmisc/chkname.c](https://github.com/shadow-maint/shadow/blob/e6b23e1431d8d798bb3c620bc26557ea44a30b98/libmisc/chkname.c#L49).

Hi,

this is the kind of thing which seems to me like it should be perfectly
safe, but for which i suspect there is a strong historical (or even
current) reason why it's refused.  I'm cc:ing the mailing list so
hopefully someone less ignorant than I can answer.

thanks,
-serge