Comment 5 for bug 661951

It seems that the scripts in /etc/NetworkManager/dispatcher.d would still have been run, because the reason for the failures was the addition of a "hostname" action to trigger dispatcher scripts on hostname changes. Any other "standard" case would have just worked as usual to run dispatcher scripts in dispatcher.d (and then the ones from /etc/network/if*.d...) for up, down, pre-up and post-down events.

As a fix, and since ifupdown action scripts don't support the 'hostname' action AFAIK, I'll apply a fix to add a case for 'hostname' to just exit with status 0 and do nothing.