add a guard for trading entity servers by checking node count

assignment-client/src/scripts/EntityScriptServer.cpp

@@ -326,7 +326,26 @@ void EntityScriptServer::nodeActivated(SharedNodePointer activatedNode) {
 void EntityScriptServer::nodeKilled(SharedNodePointer killedNode) {
     switch (killedNode->getType()) {
         case NodeType::EntityServer: {
-            clear();
+            // Before we clear, make sure this was our only entity server.
+            // Otherwise we're assuming that we have "trading" entity servers
+            // (an old one going away and a new one coming onboard)
+            // and that we shouldn't clear here because we're still doing work.
+            bool hasAnotherEntityServer = false;
+            auto nodeList = DependencyManager::get<NodeList>();
+
+            nodeList->eachNodeBreakable([&hasAnotherEntityServer, &killedNode](const SharedNodePointer& node){
+                if (node->getType() == NodeType::EntityServer && node->getUUID() != killedNode->getUUID()) {
+                    // we're talking to > 1 entity servers, we know we won't clear
+                    hasAnotherEntityServer = true;
+                    return false;
+                }
+
+                return true;
+            });
+
+            if (hasAnotherEntityServer) {
+                clear();
+            }
             
             break;
         }