iptables-persistent fails to save if ipv6 is disabled

[David Moreau Simard]

This bug was fixed upstream by Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=651903

Essentially, "service iptables-persistent save" will always attempt to save both ipv4 and ipv6 rules.
If ipv6 is disabled, aka:
  - net.ipv6.conf.all.disable_ipv6 = 1
  - net.ipv6.conf.default.disable_ipv6 = 1
  - net.ipv6.conf.lo.disable_ipv6 = 1

iptables-persistent will fail with the following message:
# service iptables-persistent save
 * Saving rules... * IPv4... * IPv6... ip6tables-save v1.4.12: Cannot initialize: Address family not supported by protocol

Hitting this bug under Ubuntu 12.04 currently with the latest version of these packages:
ii iptables 1.4.12-1ubuntu5 administration tools for packet filtering and NAT
ii iptables-persistent 0.5.3ubuntu2 boot-time loader for iptables rules

It doesn't look like I'm able to reproduce this on Ubuntu 14.04 with the latest version of these packages:
ii iptables 1.4.21-1ubuntu1 amd64 administration tools for packet filtering and NAT
ii iptables-persistent 0.5.7 all boot-time loader for iptables rules

Can we backport the necessary patch to precise ?

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[gustavo panizzo (gfa)]

this is fixed by now, otherwise open a new bug