1 files changed, 37 insertions, 1 deletions

diff --git a/src/swarm/hyparview.rs b/src/swarm/hyparview.rs
index 17d36b8..004f528 100644
--- a/src/swarm/hyparview.rs
+++ b/src/swarm/hyparview.rs
@@ -7,7 +7,9 @@
 //! link both ends agreed to (NEIGHBOUR, answered by NEIGHBOUR_REPLY), not one every
 //! node computes alike. A node with fewer asks others from its passive view, one at a
 //! time per missing neighbour; one that has none asks with high priority, and is taken
-//! even where that means dropping another (told so: DISCONNECT). A neighbour that fails
+//! even where that means dropping another (told so: DISCONNECT). One left with none
+//! (dropped so itself) while its asks are low ones has one of them, or another, made
+//! high at once, even of a member that refused before. A neighbour that fails
 //! (judged unreachable: unanswered HELLOs, dormant, not alive lately) leaves the active
 //! view, and another is asked. Every neighbour is asked again now and then whether it
 //! still is (`REAFFIRM_EVERY`): the paper's links are TCP connections, whose ends know
@@ -282,6 +284,40 @@ impl Topology for HyParView {
                     changed = true;
                 }
             }
+            // No neighbour, and no ask that would make room for us (those sent while
+            // we had some, low, refused by full members, each refused for a while):
+            // one high, an ask not sent yet made so, or another, whoever refused before
+            // if nobody else is left.
+            if views.active.is_empty() && !views.asking.values().any(|asking| asking.high) {
+                let unsent = views
+                    .asking
+                    .iter()
+                    .find(|(_, asking)| !asking.sent)
+                    .map(|(member, _)| member.clone());
+                let member = unsent.or_else(|| {
+                    let passive = Self::passive_view(&views, &reachable);
+                    let anyone: Vec<String> = if passive.is_empty() {
+                        reachable
+                            .iter()
+                            .filter(|member| !views.asking.contains_key(*member))
+                            .cloned()
+                            .collect()
+                    } else {
+                        passive
+                    };
+                    some_of(anyone, 1).pop()
+                });
+                if let Some(member) = member {
+                    views.refused.remove(&member);
+                    let asking = views.asking.entry(member).or_insert(Asking {
+                        since: now,
+                        high: true,
+                        sent: false,
+                    });
+                    asking.high = true;
+                    changed = true;
+                }
+            }
             let mut to_ask: Vec<(String, bool)> = views
                 .asking
                 .iter()