fix multi renderer creation on webguiplayer

src/main/java/net/pms/library/RootFolder.java

@@ -139,6 +139,7 @@ public synchronized void discoverChildren() {
 		if (isDiscovered()) {
 			return;
 		}
+		LOGGER.debug("Discovering the root folder for " + renderer.getRendererName());
 
 		//clear childrens but keep copy until discovered
 		backupChildren.clear();
@@ -515,6 +516,7 @@ public synchronized List<LibraryResource> getLibraryResources(String objectId, b
 
 					if (count > 0) {
 						String systemName = libraryContainer.getSystemName();
+						LOGGER.trace("Start of analysis for " + systemName);
 						ArrayBlockingQueue<Runnable> queue = new ArrayBlockingQueue<>(count);
 
 						int nParallelThreads = 3;

src/main/java/net/pms/network/webguiserver/servlets/PlayerApiServlet.java

@@ -276,7 +276,7 @@ protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws I
 		}
 	}
 
-	private static WebGuiRenderer getRenderer(HttpServletRequest req, String uuid) {
+	private static synchronized WebGuiRenderer getRenderer(HttpServletRequest req, String uuid) {
 		if (ConnectedRenderers.hasWebPlayerRenderer(uuid)) {
 			return ConnectedRenderers.getWebPlayerRenderer(uuid);
 		}
@@ -295,15 +295,17 @@ private static void createRenderer(HttpServletRequest req, String uuid) {
 			return;
 		}
 		try {
+			LOGGER.info("Founded new web gui renderer with uuid: {}", uuid);
 			String userAgent = req.getHeader("User-agent");
 			String langs = WebGuiServletHelper.getLangs(req);
 			WebGuiRenderer renderer = new WebGuiRenderer(uuid, account.getUser().getId(), userAgent, langs);
 			renderer.associateIP(WebGuiServletHelper.getInetAddress(req.getRemoteAddr()));
 			renderer.setActive(true);
-			renderer.getRootFolder();
+			//renderer.getRootFolder();
 			ConnectedRenderers.addWebPlayerRenderer(renderer);
+			LOGGER.debug("Created web gui renderer for " + renderer.getRendererName());
 		} catch (ConfigurationException ex) {
-			LOGGER.info("Error in loading configuration of WebPlayerRenderer");
+			LOGGER.warn("Error in loading configuration of WebPlayerRenderer");
 		} catch (InterruptedException ex) {
 			Thread.currentThread().interrupt();
 		}

src/main/java/net/pms/renderers/ConnectedRenderers.java

@@ -42,6 +42,7 @@
  * This class handle all renderers and devices found.
  */
 public class ConnectedRenderers {
+
 	private static final Logger LOGGER = LoggerFactory.getLogger(ConnectedRenderers.class);
 	private static final Map<InetAddress, Renderer> ADDRESS_RENDERER_ASSOCIATION = Collections.synchronizedMap(new HashMap<>());
 	private static final Map<InetAddress, String> ADDRESS_UUID_ASSOCIATION = Collections.synchronizedMap(new HashMap<>());
@@ -70,8 +71,8 @@ public static Collection<Renderer> getConnectedRenderers() {
 	}
 
 	/**
-	 * Tries to find a matching renderer configuration based on the given collection of
-	 * request headers
+	 * Tries to find a matching renderer configuration based on the given
+	 * collection of request headers
 	 *
 	 * @param headers The headers.
 	 * @param ia The request's origin address.
@@ -89,10 +90,10 @@ public static Renderer getRendererConfigurationByHeaders(SortedHeaderMap sortedH
 			r = ConnectedRenderers.resolve(ia, ref);
 			if (r != null) {
 				LOGGER.trace(
-					"Matched {}media renderer \"{}\" based on headers {}",
-					isNew ? "new " : "",
-					r.getRendererName(),
-					sortedHeaders
+						"Matched {}media renderer \"{}\" based on headers {}",
+						isNew ? "new " : "",
+						r.getRendererName(),
+						sortedHeaders
 				);
 			}
 		}
@@ -192,11 +193,7 @@ public static Renderer resolve(InetAddress ia, RendererConfiguration ref) {
 	}
 
 	public static void verify(Renderer r) {
-		// FIXME: this is a very fallible, incomplete validity test for use only until
-		// we find something better. The assumption is that renderers unable determine
-		// their own address (i.e. non-UPnP/web renderers that have lost their spot in the
-		// address association to a newer renderer at the same ip) are "invalid".
-		if (r.getUpnpMode() != Renderer.UPNP_BLOCK && r.getAddress() == null) {
+		if (!r.verify()) {
 			LOGGER.debug("Purging renderer {} as invalid", r);
 			r.delete(0);
 		}
@@ -358,15 +355,19 @@ public static String getRandomUUID() {
 
 	/**
 	 * RendererMap was marking renderer via uuid.
+	 *
 	 * @param uuid
 	 * @return Renderer
 	 */
 	public static void markRenderer(String uuid, int property, Object value) {
 		Renderer renderer = UUID_RENDERER_ASSOCIATION.get(uuid);
 		switch (property) {
-			case JUPnPDeviceHelper.ACTIVE -> renderer.setActive((boolean) value);
-			case JUPnPDeviceHelper.RENEW -> renderer.setRenew((boolean) value);
-			case JUPnPDeviceHelper.CONTROLS -> renderer.setControls((int) value);
+			case JUPnPDeviceHelper.ACTIVE ->
+				renderer.setActive((boolean) value);
+			case JUPnPDeviceHelper.RENEW ->
+				renderer.setRenew((boolean) value);
+			case JUPnPDeviceHelper.CONTROLS ->
+				renderer.setControls((int) value);
 			default -> {
 				//not handled
 			}
@@ -387,6 +388,7 @@ public static Renderer getUpNPRenderer(String uuid) {
 
 	/**
 	 * RendererMap was creating renderer on the fly if not found.
+	 *
 	 * @param uuid
 	 * @return Renderer
 	 */

src/main/java/net/pms/renderers/Renderer.java

@@ -852,6 +852,14 @@ public boolean isUpnpAllowed() {
 		return getUpnpMode() > UPNP_NONE;
 	}
 
+	public boolean verify() {
+		// FIXME: this is a very fallible, incomplete validity test for use only until
+		// we find something better. The assumption is that renderers unable determine
+		// their own address (i.e. non-UPnP/web renderers that have lost their spot in the
+		// address association to a newer renderer at the same ip) are "invalid".
+		return getUpnpMode() == Renderer.UPNP_BLOCK || getAddress() != null;
+	}
+
 	public static int getUpnpMode(String mode) {
 		if (mode != null) {
 			return switch (mode.trim().toLowerCase()) {

src/main/java/net/pms/renderers/devices/WebGuiRenderer.java

@@ -192,6 +192,16 @@ public String getSubLanguage() {
 		return subLang;
 	}
 
+	@Override
+	public boolean isAllowed() {
+		return true;
+	}
+
+	@Override
+	public void setAllowed(boolean b) {
+		//nothing to change
+	}
+
 	public void sendMessage(String... args) {
 		JsonObject jObject = new JsonObject();
 		jObject.addProperty("action", "player");