bug#57052: elogind-service specifies a variable that's ignored by defualt

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

Hi,

Maxim Cournoyer <maxim.cournoyer@gmail.com> writes:

> Hi,
>
> Liliana Marie Prikler <liliana.prikler@ist.tugraz.at> writes:
>
>> Am Sonntag, dem 07.08.2022 um 23:29 +0000 schrieb Cairn:
>>> "HandleLidSwitchExternalPower= is completely ignored by default (for
>>> backwards compatibility)"[1]
>>>
>>> I noticed (with help in IRC) that my laptop wasn't suspending on lid
>>> close when plugged in and charging, which I hadn't seen happen on
>>> other systems. I now know that I can set this by configuring the
>>> `elogind-service` parameter `handle-lid-switch-external-power`.
>>> Regardless, it seems like it should default to being unset rather
>>> than set/ignored, since that would heed the line I quoted above.
>> I think you're misreading that line.  What it states is not that
>> "HandleLidSwitchExternalPower" is ignored by default, but
>> "HandleLidSwitchExternalPower=" is ignored by default, i.e. there will
>> be no value unless one was provided (whichever semantics "no value" has
>> later on) is only confusingly explained later on.
>>
>> IMHO the Guix behaviour of always setting a value is the right one
>> (explicit is better than implicit after all).  As for the default
>> values, one might disagree as to which fits, but I don't think ignoring
>> lid switches while powered is harmful.
>
> It can be.  I have a Lenovo T430s with a partially discolored LCD from
> heat after I left it closed in a backpack for a couple hours, thinking
> it would have suspend (it was not).  That would not have happened with
> the value supposed to be default (which matches the behavior used on
> most other systems).
>
> So I'd favor having the default to suspend on any lid close.

For the record, this was noticed and discussed more than a year ago, see
Message-ID: <871rens9a2.fsf@nckx>.  It had fallen into the cracks, it
seems.

Maxim