Tested update-manager 1:0.196.13 on trusty, waited until an update happened that required a restart, and indeed the 'restart later' button had focus. Pressing spacebar dismissed the box without restarting the computer.
Tested update-manager 1:0.196.13 on trusty, waited until an update happened that required a restart, and indeed the 'restart later' button had focus. Pressing spacebar dismissed the box without restarting the computer.