partial fix for #608 - when a new TCP API connection arrives, close old one completely

src/esp32/WiFiServerAPI.cpp

@@ -28,18 +28,19 @@ void WiFiServerAPI::onConnectionChanged(bool connected)
     }
 }
 
-void WiFiServerAPI::loop()
+/// override close to also shutdown the TCP link
+void WiFiServerAPI::close() {
+    client.stop(); // drop tcp connection
+    StreamAPI::close();
+}
+
+bool WiFiServerAPI::loop()
 {
     if (client.connected()) {
         StreamAPI::loop();
-    } else if(isConnected) {
-        // If our API link was up, shut it down
-
-        DEBUG_MSG("Client dropped connection, closing API client\n");
-        // Note: we can't call delete here because this object includes other state
-        // besides the stream API.  Instead kill it later when we start a new instance
-        // delete this;
-        close();
+        return true;
+    } else {
+        return false;       
     }
 }
 
@@ -58,15 +59,25 @@ int32_t WiFiServerPort::runOnce()
     auto client = available();
     if (client) {
         // Close any previous connection (see FIXME in header file)
-        if (openAPI)
+        if (openAPI) {
+            DEBUG_MSG("Force closing previous TCP connection\n");
             delete openAPI;
+        }
 
         openAPI = new WiFiServerAPI(client);
     }
 
     if (openAPI) {
         // Allow idle processing so the API can read from its incoming stream
-        openAPI->loop();
+        if(!openAPI->loop()) {
+            // If our API link was up, shut it down
+
+            DEBUG_MSG("Client dropped connection, closing API client\n");
+            // Note: we can't call delete here because this object includes other state
+            // besides the stream API.  Instead kill it later when we start a new instance
+            delete openAPI;
+            openAPI = NULL;
+        }
         return 0; // run fast while our API server is running
     } else
         return 100; // only check occasionally for incoming connections

src/esp32/WiFiServerAPI.h

@@ -18,7 +18,11 @@ class WiFiServerAPI : public StreamAPI
 
     virtual ~WiFiServerAPI();
 
-    virtual void loop(); // Check for dropped client connections
+    /// @return true if we want to keep running, or false if we are ready to be destroyed
+    virtual bool loop(); // Check for dropped client connections
+
+    /// override close to also shutdown the TCP link
+    virtual void close();
 
   protected:
     /// Hookable to find out when connection changes