Bug#990385: apt: allow to set Valid-Until-Min/Valid-Until-Max = 0 to ignore defaults

[Christoph Anton Mitterer <calestyo@scientia.net>]

Source: apt
Version: 2.2.4
Severity: wishlist


Hey there.

It would be nice if the sources.list options Valid-Until-Min/Valid-Until-Max
would allow to be set to 0 or -1 in order to ignore any set value of their
respective defaults Acquire::Min-ValidTime and Acquire::Max-ValidTime.

The idea is as follows...


One might want to set a system-wide default to not accept Release files that
are older than, say a 2 days:
  /etc/apt/apt.conf.d/99security:
    Acquire::Max-ValidTime 172800;

This assures that "at least" 2 days are enforced even if a perhaps even
tighter:
   Valid-Until-Max: 86400
is forgotten in some repo definition.

But for e.g. local repos, where the Release file isn't recreated regularly,
this is rather undesired, of course.
Aside from simply setting a very long Valid-Until-Max, it would be nice if
one could set 0, similar to Acquire::Max-ValidTime meaning of "no maximum"
(of course unless a Valid-Until is specified in the Release file).


Cheers,
Chris.