When delegates collaborate on the repository identity, their voting
narrows the tree of active proposals to the chain of accepted
proposals. Thus, they crucially must understand which proposals are
siblings, i.e., which proposals share the same parent, because no
two sibling proposals should ever be accepted at the same time, as
this would mean a fork.
To ease collaboration of delegates and improve their overview, also
print the parent revision, if present. Note that the initial revision
is the only revision that has no parent.
Canonical references can not be used to model symbolic references.
Relax this restriction by adding another member to the payload, named
"symbolic". Its key-value/name-target pairs then translate directly to
canonical symbolic references.
Care is taken to not allow circular references, and that there always
is a rule that could generate the target of a symbolic reference
(or a chain of symbolic references). Still, a symbolic reference may
dangle (for example when its target reference cannot be computed
because of divergence), but at least it can be prevented that a
symref *always* dangles, because there is no rule that would produce
its target.
Co-authored-by: Fintan Halpenny <fintan.halpenny@gmail.com>
Lorenz Leutgeb