A long name of one parameter was making the whole thing very wide.
I think that it's obvious from the context what the argument is,
so a shorter name should be just as good.
These functions are used pretty much independently of locale, i.e. the
only info relevant is whether th locale is UTF-8 or not. Hence let's
give this its own pair of .c/.h files.
In general we almost never hit those asserts in production code, so users see
them very rarely, if ever. But either way, we just need something that users
can pass to the developers.
We have quite a few of those asserts, and some have fairly nice messages, but
many are like "WTF?" or "???" or "unexpected something". The error that is
printed includes the file location, and function name. In almost all functions
there's at most one assert, so the function name alone is enough to identify
the failure for a developer. So we don't get much extra from the message, and
we might just as well drop them.
Dropping them makes our code a tiny bit smaller, and most importantly, improves
development experience by making it easy to insert such an assert in the code
without thinking how to phrase the argument.
Let's add three defines for the 3 special cases of passwords.
Some of our tools used different values for the "locked"/"invalid" case,
let's settle on using "!*" which means the password is both locked *and*
invalid.
Other tools like to use "!!" for this case, which however is less than
ideal I think, since the this could also be a considered an entry with
an empty password, that can be enabled again by unlocking it twice.
Let's enable this in all tools that intend to write to the OS images.
It's not conditionalized for now, as there already is conditionalization
in the existance or absence of the flag in the GPT partition table (and
it's opt-in), hence it should be OK to just enable this by default for
now if the flag is set.
Previously, the flag did two things at once: enable support for using
generic partitions as root fs if there were only one/allow use of
partition-table-less images as root fs. And secondly, insist that there
was a rootfs, and fail if not. Let's split these two in two separate
options so that they can be used independently of each other.
There are cases where one wants to use one without the other (i.e. when
inspecting things with systemd-dissect tool it should be OK to do so
even if image has no root fs), and it's cleaner anyway.
It's so similar to copy_access(), hence let's move it over and rename it
in similar style to the rest of the functions.
No change in behaviour, just moving things over.
I think this formatting was originally used because it simplified
adding new options to the help messages. However, these days, most
tools their help message end with "\nSee the %s for details.\n" so
the final line almost never has to be edited which eliminates the
benefit of the custom formatting used for printf() help messages.
Let's make things more consistent and use the same formatting for
printf() help messages that we use everywhere else.
Prompted by https://github.com/systemd/systemd/pull/18355#discussion_r567241580
Let's clean up hostname_is_valid() a bit: let's turn the second boolean
argument into a more explanatory flags field, and add a flag that
accepts the special name ".host" as valid. This is useful for the
container logic, where the special hostname ".host" refers to the "root
container", i.e. the host system itself, and can be specified at various
places.
let's also get rid of machine_name_is_valid(). It was just an alias,
which is confusing and even more so now that we have the flags param.
