periodic: Fix empty output check

[des]

Summary

The empty_output variable is normalized to YES or NO, but we were
comparing it to TRUE, so the comparison always failed no matter what it
was set to. Compare it to YES instead.

Since this feature has never worked, flip the default to NO to preserve
the current behavior. Adjust the documentation accordingly.

Relnotes: yes
PR: 300676
MFC after: 1 week
Fixes: 68c35072f914 ("Add an option to make periodic(8) quiet when no output was generated.")

[ivy]

Fixes: 68c35072f914 ("Add an option to make periodic(8) quiet when no output was generated.")

these should probably be added to /etc/defaults/periodic.conf as well. and perhaps the manpage language should be inverted: if _show_empty_output is set to YES, mail will be sent. or, mail will not be sent unless it's set to YES. basically, document the explicit setting, not the default. currently we only document the (effective) default option and not how to enable output.

i think this should also be documented in periodic.conf.5 alongside _show_success, _show_info, etc.

[emaste]

usr.sbin/periodic/periodic.8

141–142

We could document the default behaviour and describe setting the variable to YES, although given that this has not worked for about two decades and the feature is not particularly useful IMO I think it's fine as is.

[ivy]

usr.sbin/periodic/periodic.8

141–142

i appreciate where you're coming from, but i don't think "it's not very useful" is a good justification here. if it's really that useless, it should be removed; otherwise it should be documented properly. having it implemented but not documented is neither here nor there.

[des]

rf

[ivy]

defaults not added to /etc/defaults/periodic.conf, was that intentional? i won't force this but i do feel it should be documented there.