chat_core_connect_auto: dedup addresses by (addr,port)

tools/chatgui/transport/chat_core.c

@@ -1006,6 +1006,15 @@ void chat_core_connect_auto(uint64_t node_id,
         }
         sqlite3_finalize(st);
     }
+    /* dedup by (addr, port) — can't have two links to same socket */
+    { int uniq = 0;
+      for (int i = 0; i < addr_count; i++) {
+          int dup = 0;
+          for (int j = 0; j < uniq; j++)
+              if (memcmp(addrs[i].addr, addrs[j].addr, 4) == 0 && addrs[i].port == addrs[j].port) { dup = 1; break; }
+          if (!dup) { if (i != uniq) addrs[uniq] = addrs[i]; uniq++; }
+      }
+      addr_count = uniq; }
     if (addr_count == 0) {
         DEBUG_ERROR(DEBUG_CATEGORY_CONNECTIVITY, "%s: auto_connect no IPv4 addrs for node 0x%016llx",
                     CC_ID, (unsigned long long)node_id);