Set default HOME_MODE to 0700

[weseven]

Since the introduction of #209, many distros started to set HOME_MODE by default:

• RedHat & RH based distro like Fedora, but also Arch linux, OpenSuse all set it to 0700
• Ubuntu sets it to 0750
• notable exceptions are Debian and Gentoo that keep the variable unset.

I propose to set it to 0700 or at least 0750 by default, since it is a security best practice and it's something often tested by security benchmarks (e.g., CIS Benchmarks).

[hallyn]

No - distros like debian may get caught off guard. There's nothing wrong with downstreams patching their values in their deltas. We do not lightly make changes which change defaults.

[weseven]

Understood, thanks for taking a look.
Is there a possibility this change will be applied here in the future, and in the meantime give maintainers a notice that this will happen after some releases?

I still think it's a better default value than leaving it unset, and its impact is limited to useradd and newusers.
I understand your concern in possibly changing historic behavior and respecting downstream maintainers, but it's also a downstream maintainer responsibility to read upstream changes and adapt the defaults to the distro expected use case.