OpenConnections: Improved handling of zero clients

src/OpenConnections.cpp

@@ -6,14 +6,17 @@ void OpenConnectionsList::Add(SubscriptionHandler::RequestHandle hdl) {
 }
 
 void OpenConnectionsList::Publish(const std::string &msg) {
-    std::vector<SubscriptionHandler::RequestHandle> newHdls;
-    newHdls.reserve(hdls.size());
-    for (auto& hdl: hdls) {
-        if (hdl->Ok()) {
-            hdl->SendMessage(msg);
-            newHdls.emplace_back(std::move(hdl));
+    if (hdls.size() > 0) {
+        std::vector<SubscriptionHandler::RequestHandle> newHdls;
+        newHdls.reserve(hdls.size());
+
+        for (auto& hdl: hdls) {
+            if (hdl->Ok()) {
+                hdl->SendMessage(msg);
+                newHdls.emplace_back(std::move(hdl));
+            }
         }
-    }
 
-    hdls = std::move(newHdls);
+        hdls = std::move(newHdls);
+    }
 }

test/sub.cpp

@@ -61,6 +61,26 @@ class ClientPublisher: public StreamClient {
     PipePublisher<std::string> publisher;
 };
 
+TEST(ZERO_CLIENTS, Publish) {
+    std::shared_ptr<TestHandler> handler;
+    handler = TestHandler::New();
+    WorkerThread           serverThread;
+    RequestServer          server;
+
+    server.AddHandler(TestHandler::SUB_TYPE, handler);
+    // Request server's main loop is blocking, start up on a slave thread...
+    serverThread.PostTask([&] () -> void {
+        server.HandleRequests(serverPort);
+    });
+    serverThread.Start();
+
+    // wait for the server to spin up...
+    server.WaitUntilRunning();
+
+    ASSERT_NO_THROW(handler->Publish(""));
+
+}
+
 class SubTest: public ::testing::Test {
 public:
     SubTest()