This commit adds the flags and some basic formatting/printing of them.
Following commits will integrate them into the update/acquire/install
logic.
`UPDATE_PARTIAL` is set if any of the instances in the `UpdateSet` are
partial, i.e. have been partially downloaded.
`UPDATE_PENDING` is set if any of the instances in the `UpdateSet` are
pending, i.e. have been acquired (downloaded) but not yet installed.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Helps: https://github.com/systemd/systemd/issues/34814
Let's not leak details from src/shared and src/libsystemd into
src/basic, even though you can't actually do anything useful with
just forward declarations from src/shared.
The sd-forward.h header is put in src/libsystemd/sd-common as we
don't have a directory for shared internal headers for libsystemd
yet.
Let's also rename forward.h to basic-forward.h to keep things
self-explanatory.
When enumerating what versions exist for a given target, sysupdate would
completely throw out any version that's incomplete (where some of the
transfers in the target have that version installed or available, and
other transfers do not).
If we're trying to find what versions we can offer for download, this is
great behavior. If the server side is advertising a partial update to
download, we shouldn't present it to the user.
On the other hand, if we're enumerating what versions we have currently
installed, this is a bad behavior. It makes sysupdate fragile. For
example, if a sysext introduces a new .conf file into
/usr/lib/sysupdate.d, suddenly the currently-installed OS stops being a
version that we've enumerated. Since it's not enumerated, it's not
protected, and so sysupdate will wipe the booted OS.
So if we're looking for installed versions, we now loosen the
restrictions and enumerate incomplete installations.
Partial fix for https://github.com/systemd/systemd/issues/33339