POSIX_ME_HARDER mode is disabled for localectl. It doesn't
make much sense in case of localectl, and there's little reason
for localectl to behave specially.
Before, we would initialize many fields twice: first
by filling the structure with zeros, and then a second
time with the real values. We can let the compiler do
the job for us, avoiding one copy.
A downside of this patch is that text gets slightly
bigger. This is because all zero() calls are effectively
inlined:
$ size build/.libs/systemd
text data bss dec hex filename
before 897737 107300 2560 1007597 f5fed build/.libs/systemd
after 897873 107300 2560 1007733 f6075 build/.libs/systemd
… actually less than 1‰.
A few asserts that the parameter is not null had to be removed. I
don't think this changes much, because first, it is quite unlikely
for the assert to fail, and second, an immediate SEGV is almost as
good as an assert.
gcc thinks that errno might be negative, and functions could return
something positive on error (-errno). Should not matter in practice,
but makes an -O4 build much quieter.
Not all systems ships with locales inside /usr/lib/locale-archive, some
prefer to have locale data as individual subdirectories of /usr/lib/locale.
(A notable example of this is OpenEmbeddded, and OSes deriving from it
like gnome-ostree).
Given that glibc supports both ways, localectl should too.
l might contain zero strings, however there is still memory
allocated for NULL terminator, use _cleanup_strv_free_ instead to
prevent tiny leak in such case.