Bug#914001: live-config: Assume that RTC is in localtime if Windows is detected

[intrigeri@debian.org]

Source: live-config
Severity: wishlist
Version: 5.20180224
User: tails-dev@boum.org
Usertags: misc-reported

Hi,

below, I'll assume that #882851 is fixed.

Tails users experience important issues when their RTC is in
localtime. It's too hard for non-technical users to 1. guess that the
problems they're experiencing might be related to the RTC's timezone;
2. find out whether their RTC is in localtime; 3. pass utc=no every
time they start Tails.

So it would be nice if live-config supported utc=auto, which would do
exactly the same thing as Debian Installer does [1]: if a Windows
installation is detected, assume that the RTC is in localtime. I would
suggest:

 - implement support for utc=auto in components/1120-util-linux;
   ideally, if os-prober is available, make utc=auto the default; but
   of course, let the kernel cmdline utc= option override it

 - add Recommends: os-prober (I guess not everyone wants to pull its
   dependency on grub-common)

Thoughts?

[1] https://salsa.debian.org/installer-team/clock-setup/blob/master/finish-install.d/10clock-setup#L69

Cheers,
-- 
intrigeri