Bug#792853: debian-policy: please disallow colons in upstream_version

[Jakub Wilk <jwilk@debian.org>]

Package: debian-policy
Severity: wishlist

Policy §5.6.12 reads: “The <upstream_version> may contain only 
alphanumerics and the characters ‘.’  ‘+’ ‘-’ ‘:’ ‘~’ (full stop, plus, 
hyphen, colon, tilde) and should start with a digit. […] if there is no 
<epoch> then colons are not allowed.”

But in practice:

1) There's been never a package with a colon in upstream_version in the 
archive.

2) A colon in upstream_version implies a colon in the filename. Some 
software might not tolerate such filenames; see bug #645895 for 
discussion.

3) dpkg in unstable won't even let you build a package with such 
version:

$ head -n1 debian/changelog
adequate (1:1:1) UNRELEASED; urgency=low
$ dpkg-buildpackage -S
[…]
dpkg-genchanges -S >../adequate_1:1_source.changes
dpkg-genchanges: error: invalid filename adequate_1:1.dsc
dpkg-buildpackage: error: dpkg-genchanges gave error exit status 255


Therefore, I'd like to propose to disallow colons in upstream_version.

--
Jakub Wilk