[Pkg-shadow-devel] "." in usernames, ambiguity, and +

[Justin Pryzby]

Hi Everyone,

I seem to recall about 1 year ago reading a discussion regarding
resolution of an ambiguity centered around use of "." in usernames.  I
think the problem was that . is also a possible separator between user
and group names in eg. chmod/chown.  I forget exactly where the original
discussion was (passwd bug log?) and any details.  However I just
happened on some additional relevant information.

POSIX apparently requires looking up the username if it's ambiguous, and
falling back to interpretation as a UID.  However apparently GNU uses +
to force interpretation as a UID:
http://www.gnu.org/software/coreutils/manual/html_node/Disambiguating-names-and-IDs.html#Disambiguating-names-and-IDs

What/where was the previous discussion?  Is this even relevant?  Was the
ultimate decision consistent with the other tools or could it be
improved?

Thanks,
Justin