We may need to avoid using a cached temp directory for testing purposes,
so let's provide an internal API to perform such task.
This implies removing GOnce and going with mutex-based version, but
that's still using atomic logic in most unix implementations anyways.
These leaks happens "by design" in case that the private API
g_set_user_dirs() is used to replace directories during some tests.
And we've to leak the previously set values (if any) not to free strings
that may be used by other user code before.
In fact we're already ignoring LSAN reports for the very same reason
here.
We could create a private suppression file too, but I don't think we've to
bother with that, given that user code should never hit this path
anyways.
It's the only leak we have, sooo:
Fixes: https://gitlab.gnome.org/GNOME/glib/-/issues/333
xdgmime makes some one-off allocations when being set up. Ignore them in
the suppression file, since they’re not really a leak.
This should fix the contenttype test running under valgrind.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>