roots: a joiner takes a root once its seeds named it

Review 3, R2: the root pin was set by the first HELLO_REPLY, and the
first sync, a round trip later, took that root; a peer naming another
afterwards was refused as another history. So the seed that answered
first decided, not "none while they disagree", and a malicious seed
makes itself fastest.

A node joining with an empty document of the first epoch now takes no
root (RootPin::Awaiting, roots left for later) until each of its seeds
named one, or ROOT_WAIT (10 s) passed since the first did; then the
one they name, none while they differ, as before. With --genesis-root
it takes that one alone, at once. access.md, the option's help and
example.toml say so; switching roots later, while the joiner holds
nothing of its own, is postponed.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/node.rs b/src/node.rs
index c74d7c0..91a9c62 100644
--- a/src/node.rs
+++ b/src/node.rs
@@ -175,6 +175,7 @@ impl Node {
                 crate::access::screen::Screening::pinned(crate::swarm::roots::pin(
                     config.genesis_root,
                     &Default::default(),
+                    false,
                 )),
             )),
             roots: Default::default(),