Bug#844315: tzdata version breaks dist-upgrade leaving version from oldstable security installed

[Marcel Meckel <debian@thermoman.de>]

Package: tzdata
Version: 2016i-0+deb7u1
Severity: critical

Upgrading a fully updated wheezy system (incl. security repo) to
jessie (incl. security repo) results in tzdata not being updated
because the version in wheezy-security is newer than in jessie.

Package tzdata on amd64

  wheezy:                  2016d-0+deb7u1
  wheezy-security:         2016i-0+deb7u1

  jessie:                  2016f-0+deb8u1
  jessie-updates:          2016i-0+deb8u1
  jessie-proposed-updates: 2016i-0+deb8u1

Using only the main repo + security repo results in tzdata not being
updates since wheezy-securities '2016i-0+deb7u1' is higher than
jessies '2016f-0+deb8u1'.

Comment from IRC:

<petn-randall> That's indeed unfortunate. You can work around the
problem by adding jessie-updates, though.

<petn-randall> I think it's because wheezy didn't have a wheezy-updates,
so all updates must go through wheezy-security, whereas in jessie all
non-critical updates go through jessie-updates, and get wrapped up in
point releases every few months.

<petn-randall> It's still a bug though, I'd report it on the tzdata
package. Might warrant a RC severity, since it breaks automatic upgrades
and is easy to fix.