DEP14 policy for two dots

[Ian Jackson]

Raphael Hertzog writes ("Re: DEP14 policy for two dots"):
> We have defined simple "readable" mappings for the common cases that
> we encounter frequently. Now if we need mappings for silly things
> that we don't encounter, I would suggest to use something easily
> reversible and extendable.

My proposal is reversible.  It does not need to be extensible.
(Although before we adopt it it does need a review to make sure that I
have read the manuals correctly.  I see that I have failed to specify
s/\.lock$/.#lock/.)

Debian version numbers can contain only:

 ASCII alphanumerics     Permitted freely in git ref names

 + -                     Permitted freely in git ref names

 : ~                     Forbidden in git ref names; replaced by
                         % and _ which are permitted freely by git

 .                       Permitted in git ref names subject to
                         restrictions

> My suggestion would be to allow "#<hexadecimal unicode code point>#". 
> Thus my personal preference would be to replace ".." with ".#2e#".

This is a bad idea because it (implicitly) makes the conversion
nondeterministic.  It is also unnecessary to consider unicode code
points other than 7-bit ASCII because Debian version numbers may
contain only 7-bit ASCII.

You might write some rule about which . should be replaced by #2e#
but it would be easy to misimplement.

Also if we are going to introduce an arbitrary codepoint quoting
system like this it should be identical to quoted-printable (bad as
that is).

> No, a version can't start with a dot, at least dpkg has been ensuring
> this for a few years now.

Then that part of my proposed rule is a harmless nullity.

Ian.

-- 
Ian Jackson <ijackson at chiark.greenend.org.uk>   These opinions are my own.

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