Refactor test for existing peer connection into own function

src/net.cpp

@@ -354,6 +354,11 @@ CNode* CConnman::FindNode(const CService& addr)
     return nullptr;
 }
 
+bool CConnman::AlreadyConnectedToAddress(const CAddress& addr)
+{
+    return FindNode(static_cast<CNetAddr>(addr)) || FindNode(addr.ToStringIPPort());
+}
+
 bool CConnman::CheckIncomingNonce(uint64_t nonce)
 {
     LOCK(cs_vNodes);
@@ -2160,7 +2165,7 @@ void CConnman::OpenNetworkConnection(const CAddress& addrConnect, bool fCountFai
     }
     if (!pszDest) {
         bool banned_or_discouraged = m_banman && (m_banman->IsDiscouraged(addrConnect) || m_banman->IsBanned(addrConnect));
-        if (IsLocal(addrConnect) || FindNode(static_cast<CNetAddr>(addrConnect)) || banned_or_discouraged || FindNode(addrConnect.ToStringIPPort())) {
+        if (IsLocal(addrConnect) || banned_or_discouraged || AlreadyConnectedToAddress(addrConnect)) {
             return;
         }
     } else if (FindNode(std::string(pszDest)))

src/net.h

@@ -442,6 +442,12 @@ private:
     CNode* FindNode(const std::string& addrName);
     CNode* FindNode(const CService& addr);
 
+    /**
+     * Determine whether we're already connected to a given address, in order to
+     * avoid initiating duplicate connections.
+     */
+    bool AlreadyConnectedToAddress(const CAddress& addr);
+
     bool AttemptToEvictConnection();
     CNode* ConnectNode(CAddress addrConnect, const char *pszDest, bool fCountFailure, ConnectionType conn_type);
     void AddWhitelistPermissionFlags(NetPermissionFlags& flags, const CNetAddr &addr) const;