feat: enhance recovered signature propagation by leveraging full-mesh connections for all members

Author: PastaPastaPasta

src/llmq/utils.cpp

@@ -862,7 +862,19 @@ bool EnsureQuorumConnections(const Consensus::LLMQParams& llmqParams, CConnman&
     if (isMember) {
         connections = GetQuorumConnections(llmqParams, dmnman, qsnapman, sporkman, pQuorumBaseBlockIndex, myProTxHash,
                                            true);
-        relayMembers = GetQuorumRelayMembers(llmqParams, dmnman, qsnapman, pQuorumBaseBlockIndex, myProTxHash, true);
+        // If all-members-connected is enabled for this quorum type, leverage the full-mesh
+        // connections for low-latency recovered sig propagation by treating all members as
+        // relay members (instead of the ring-based subset). This ensures peers will send
+        // QSENDRECSIGS to each other across the full mesh and set m_wants_recsigs widely.
+        if (IsAllMembersConnectedEnabled(llmqParams.type, sporkman)) {
+            for (const auto& dmn : members) {
+                if (dmn->proTxHash != myProTxHash) {
+                    relayMembers.emplace(dmn->proTxHash);
+                }
+            }
+        } else {
+            relayMembers = GetQuorumRelayMembers(llmqParams, dmnman, qsnapman, pQuorumBaseBlockIndex, myProTxHash, true);
+        }
     } else {
         auto cindexes = CalcDeterministicWatchConnections(llmqParams.type, pQuorumBaseBlockIndex, members.size(), 1);
         for (auto idx : cindexes) {