Comment 32 for bug 1033226

thedanyes, I think your hypothetical is addressed by my previous comment. If Ubuntu becomes extremely popular, and the proportion of people who delay restarting becomes a substantial security problem, it may indeed become necessary to "force" restarting, by changing the "Install" button to "Install and Restart" -- which, if clicked, logs out to a special session where Software Updater is the only thing running and it restarts when done. But for now at least, we aren't doing that.

Anyway, I've completed the design for this. <https://wiki.ubuntu.com/SoftwareUpdates?action=diff&rev2=101&rev1=100> A fair bit of work will be involved in keeping it all looking simple, but this is a summary of the changes required:

1. Software Updater should launch automatically not just when it has been 24 hours since you were last reminded that security updates were available, but also 24 hours since you were last reminded to restart to finish installing security updates. The reason is exactly the same in both cases; as long as the installation isn't finished, you aren't secure. And analogously for non-security updates with the non-security update interval.

2. The restart-required alert should have a "Restart Later" button. Hooray!

3. If updates are available *and* a restart is required to install previous updates, the latter should be shown with secondary text in the updates alert.

4. If updates are available and a restart is required to install both these updates *and* previous updates, we shouldn't bother with the "The computer will need to restart" text, because the computer already does need to restart.

5. When installation completes (whether successfully or unsuccessfully), Software Updater should generally behave as if you have just launched it manually -- showing whether updates are (still) waiting to be installed, a restart is required, both, or neither. This should simplify the code a bit.