The subpath is resolved relative to the root of the commit, so we can
use either an absolute or a relative path interchangeably. When using
libostree < 2021.6 with GLib >= 2.71, absolute paths cause an assertion
failure here; that was a libostree bug and was fixed in 2021.6, but we
can interoperate with more versions by sticking to relative paths, and
there's no real reason to prefer absolute.
Resolves: https://github.com/flatpak/flatpak/issues/4805
Co-authored-by: Corentin Noël <corentin.noel@collabora.com>
Signed-off-by: Simon McVittie <smcv@collabora.com>
2df1b1628c