From 42e921c74bca0a0ca6b469c1525e5415e39404dd Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Wed, 11 May 2022 12:09:19 +0300
Subject: [PATCH 01/20] Fix issues with message handler and sender

---
 .../client/communication/MessageSender.java   | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
index 12381c8929e..19cdf900433 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
@@ -46,6 +46,8 @@ public class MessageSender {
     private final Registry registry;
     private final PushConnectionFactory pushConnectionFactory;
 
+    private boolean resynchronizeRequested = false;
+
     /**
      * Creates a new instance connected to the given registry.
      *
@@ -88,7 +90,7 @@ public void sendInvocationsToServer() {
     private void doSendInvocationsToServer() {
 
         ServerRpcQueue serverRpcQueue = registry.getServerRpcQueue();
-        if (serverRpcQueue.isEmpty()) {
+        if (serverRpcQueue.isEmpty() && !resynchronizeRequested) {
             return;
         }
 
@@ -96,7 +98,7 @@ private void doSendInvocationsToServer() {
         JsonArray reqJson = serverRpcQueue.toJson();
         serverRpcQueue.clear();
 
-        if (reqJson.length() == 0) {
+        if (reqJson.length() == 0 && !resynchronizeRequested) {
             // Nothing to send, all invocations were filtered out (for
             // non-existing connectors)
             Console.warn(
@@ -105,6 +107,12 @@ private void doSendInvocationsToServer() {
         }
 
         JsonObject extraJson = Json.createObject();
+        if (resynchronizeRequested) {
+            getMessageHandler().onResynchronize();
+            Console.log("Resynchronizing from server");
+            extraJson.put(ApplicationConstants.RESYNCHRONIZE_ID, true);
+            resynchronizeRequested = false;
+        }
         if (showLoadingIndicator) {
             ConnectionIndicator.setState(ConnectionIndicator.LOADING);
         }
@@ -218,10 +226,9 @@ public String getCommunicationMethodName() {
      * state from the server
      */
     public void resynchronize() {
-        Console.log("Resynchronizing from server");
-        JsonObject resyncParam = Json.createObject();
-        resyncParam.put(ApplicationConstants.RESYNCHRONIZE_ID, true);
-        send(Json.createArray(), resyncParam);
+        Console.log("Resynchronize from server requested");
+        resynchronizeRequested = true;
+        sendInvocationsToServer();
     }
 
     /**

From b0c10236443d6170fd3192a6b414317014e1d0d4 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Wed, 11 May 2022 12:18:33 +0300
Subject: [PATCH 02/20] Fix issues with message handler and sender

---
 .../client/communication/MessageHandler.java    | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
index c860e76c57d..bf981dbd9f9 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
@@ -66,6 +66,8 @@ public class MessageHandler {
      */
     private static final int UNDEFINED_SYNC_ID = -1;
 
+    private boolean resyncInProgress;
+
     /**
      * If responseHandlingLocks contains any objects, response handling is
      * suspended until the collection is empty or a timeout has occurred.
@@ -217,7 +219,17 @@ public void handleMessage(final ValueMap json) {
     protected void handleJSON(final ValueMap valueMap) {
         final int serverId = getServerId(valueMap);
 
-        if (isResynchronize(valueMap) && !isNextExpectedMessage(serverId)) {
+        boolean hasResynchronize = isResynchronize(valueMap);
+
+        if (!hasResynchronize && resyncInProgress) {
+            Console.warn(
+                    "Dropping the response of a request before a resync request.");
+            return;
+        }
+
+        resyncInProgress = false;
+
+        if (hasResynchronize && !isNextExpectedMessage(serverId)) {
             // Resynchronize request. We must remove any old pending
             // messages and ensure this is handled next. Otherwise we
             // would keep waiting for an older message forever (if this
@@ -820,4 +832,7 @@ public void setNextResponseSessionExpiredHandler(
         this.nextResponseSessionExpiredHandler = nextResponseSessionExpiredHandler;
     }
 
+    public void onResynchronize() {
+        resyncInProgress = true;
+    }
 }

From f6f2e9288660c1c6ba328f3edf16c10d58bb9d44 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Wed, 11 May 2022 12:31:38 +0300
Subject: [PATCH 03/20] Fix

---
 .../java/com/vaadin/client/communication/MessageSender.java     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
index 19cdf900433..8c1408b91f7 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
@@ -108,7 +108,7 @@ private void doSendInvocationsToServer() {
 
         JsonObject extraJson = Json.createObject();
         if (resynchronizeRequested) {
-            getMessageHandler().onResynchronize();
+            registry.getMessageHandler().onResynchronize();
             Console.log("Resynchronizing from server");
             extraJson.put(ApplicationConstants.RESYNCHRONIZE_ID, true);
             resynchronizeRequested = false;

From c86d3c567eaa0a98b7d7d2540e715fac1fd8d737 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 14:33:28 +0300
Subject: [PATCH 04/20] Expose resynchronizeRequested

---
 .../java/com/vaadin/client/communication/MessageSender.java   | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
index 8c1408b91f7..ffed558813d 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
@@ -270,4 +270,8 @@ public void setClientToServerMessageId(int nextExpectedId, boolean force) {
             // Do nothing as they will arrive eventually
         }
     }
+
+    boolean isResynchronizeRequested{
+        return resynchronizeRequested;
+    }
 }

From c659a8329f41b266e6696edec9cb0530b9475c81 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 14:35:18 +0300
Subject: [PATCH 05/20] Use resynchronizeRequested in end request

---
 .../vaadin/client/communication/RequestResponseTracker.java  | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java b/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
index 6e5732db9a9..38cbb8b0839 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
@@ -108,8 +108,9 @@ public void endRequest() {
         // the call.
         hasActiveRequest = false;
 
-        if (registry.getUILifecycle().isRunning()
-                && registry.getServerRpcQueue().isFlushPending()) {
+        if ((registry.getUILifecycle().isRunning()
+                && registry.getServerRpcQueue().isFlushPending())
+                || registry.getMessageSender().isResynchronizeRequested()) {
             // Send the pending RPCs immediately.
             // This might be an unnecessary optimization as ServerRpcQueue has a
             // finally scheduled command which trigger the send if we do not do

From 3e446421757407c96ee756dd5abb51b06b0c46a1 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 14:35:49 +0300
Subject: [PATCH 06/20] Update
 flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java

Co-authored-by: Artur <artur@vaadin.com>
---
 .../java/com/vaadin/client/communication/MessageHandler.java    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
index bf981dbd9f9..384e0252e34 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
@@ -223,7 +223,7 @@ protected void handleJSON(final ValueMap valueMap) {
 
         if (!hasResynchronize && resyncInProgress) {
             Console.warn(
-                    "Dropping the response of a request before a resync request.");
+                    "Ignoring message from the server as a resync request is ongoing.");
             return;
         }
 

From cf89ec468842d71cb4554072a82b3557323ec989 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 14:38:10 +0300
Subject: [PATCH 07/20] Fix typo

---
 .../java/com/vaadin/client/communication/MessageSender.java     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
index ffed558813d..90a013071bf 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
@@ -271,7 +271,7 @@ public void setClientToServerMessageId(int nextExpectedId, boolean force) {
         }
     }
 
-    boolean isResynchronizeRequested{
+    boolean isResynchronizeRequested() {
         return resynchronizeRequested;
     }
 }

From 925d7d04245aee1cde94303f290109d5e375b602 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 15:59:49 +0300
Subject: [PATCH 08/20] Join ResynchronizationStatus in one enum

---
 .../client/communication/MessageSender.java   | 25 +++++++++++++------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
index 90a013071bf..30ae88423c7 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
@@ -37,6 +37,10 @@
  */
 public class MessageSender {
 
+    public enum ResynchronizationState {
+        NOT_ACTIVE, SEND_TO_SERVER, WAITING_FOR_RESPONSE
+    }
+
     /**
      * Counter for the messages send to the server. First sent message has id 0.
      */
@@ -46,7 +50,7 @@ public class MessageSender {
     private final Registry registry;
     private final PushConnectionFactory pushConnectionFactory;
 
-    private boolean resynchronizeRequested = false;
+    private ResynchronizationState resynchronizationState = ResynchronizationState.NOT_ACTIVE;
 
     /**
      * Creates a new instance connected to the given registry.
@@ -90,7 +94,8 @@ public void sendInvocationsToServer() {
     private void doSendInvocationsToServer() {
 
         ServerRpcQueue serverRpcQueue = registry.getServerRpcQueue();
-        if (serverRpcQueue.isEmpty() && !resynchronizeRequested) {
+        if (serverRpcQueue.isEmpty()
+                && resynchronizationState != ResynchronizationState.SEND_TO_SERVER) {
             return;
         }
 
@@ -98,7 +103,8 @@ private void doSendInvocationsToServer() {
         JsonArray reqJson = serverRpcQueue.toJson();
         serverRpcQueue.clear();
 
-        if (reqJson.length() == 0 && !resynchronizeRequested) {
+        if (reqJson.length() == 0
+                && resynchronizationState != ResynchronizationState.SEND_TO_SERVER) {
             // Nothing to send, all invocations were filtered out (for
             // non-existing connectors)
             Console.warn(
@@ -107,11 +113,10 @@ private void doSendInvocationsToServer() {
         }
 
         JsonObject extraJson = Json.createObject();
-        if (resynchronizeRequested) {
-            registry.getMessageHandler().onResynchronize();
+        if (resynchronizationState == ResynchronizationState.SEND_TO_SERVER) {
+            resynchronizationState = ResynchronizationState.WAITING_FOR_RESPONSE;
             Console.log("Resynchronizing from server");
             extraJson.put(ApplicationConstants.RESYNCHRONIZE_ID, true);
-            resynchronizeRequested = false;
         }
         if (showLoadingIndicator) {
             ConnectionIndicator.setState(ConnectionIndicator.LOADING);
@@ -271,7 +276,11 @@ public void setClientToServerMessageId(int nextExpectedId, boolean force) {
         }
     }
 
-    boolean isResynchronizeRequested() {
-        return resynchronizeRequested;
+    void setResynchronizationState(ResynchronizationState state) {
+        resynchronizationState = state;
+    }
+
+    ResynchronizationState getResynchronizationState() {
+        return resynchronizationState;
     }
 }

From 2eb3d47e9a571f80a55a5de938094d1313e0dd05 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 16:02:33 +0300
Subject: [PATCH 09/20] Use ResynchronizationState from MessageSender

---
 .../vaadin/client/communication/MessageHandler.java  | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
index 384e0252e34..c7f4665d8f9 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
@@ -66,8 +66,6 @@ public class MessageHandler {
      */
     private static final int UNDEFINED_SYNC_ID = -1;
 
-    private boolean resyncInProgress;
-
     /**
      * If responseHandlingLocks contains any objects, response handling is
      * suspended until the collection is empty or a timeout has occurred.
@@ -221,13 +219,15 @@ protected void handleJSON(final ValueMap valueMap) {
 
         boolean hasResynchronize = isResynchronize(valueMap);
 
-        if (!hasResynchronize && resyncInProgress) {
+        if (!hasResynchronize && registry.getMessageSender()
+                .getResynchronizationState() == ResynchronizationState.WAITING_FOR_RESPONSE) {
             Console.warn(
                     "Ignoring message from the server as a resync request is ongoing.");
             return;
         }
 
-        resyncInProgress = false;
+        registry.getMessageSender()
+                .setResynchronizationState(ResynchronizationState.NOT_ACTIVE);
 
         if (hasResynchronize && !isNextExpectedMessage(serverId)) {
             // Resynchronize request. We must remove any old pending
@@ -831,8 +831,4 @@ public void setNextResponseSessionExpiredHandler(
             Command nextResponseSessionExpiredHandler) {
         this.nextResponseSessionExpiredHandler = nextResponseSessionExpiredHandler;
     }
-
-    public void onResynchronize() {
-        resyncInProgress = true;
-    }
 }

From f215a769beef7e8a0542dfb0e7b967676259be16 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 16:04:51 +0300
Subject: [PATCH 10/20] Use ResynchronizationState from MessageSender

---
 .../com/vaadin/client/communication/RequestResponseTracker.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java b/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
index 38cbb8b0839..b2d3db2fc9f 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
@@ -110,7 +110,7 @@ public void endRequest() {
 
         if ((registry.getUILifecycle().isRunning()
                 && registry.getServerRpcQueue().isFlushPending())
-                || registry.getMessageSender().isResynchronizeRequested()) {
+                || registry.getMessageSender().getResynchronizationState() == ResynchronizationState.SEND_TO_SERVER) {
             // Send the pending RPCs immediately.
             // This might be an unnecessary optimization as ServerRpcQueue has a
             // finally scheduled command which trigger the send if we do not do

From 9aa544cc8f12f48b02fb03e4584747886cc4d493 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 16:07:13 +0300
Subject: [PATCH 11/20] Add import

---
 .../java/com/vaadin/client/communication/MessageHandler.java     | 1 +
 1 file changed, 1 insertion(+)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
index c7f4665d8f9..b888a8fa536 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
@@ -27,6 +27,7 @@
 import com.vaadin.client.UILifecycle.UIState;
 import com.vaadin.client.ValueMap;
 import com.vaadin.client.WidgetUtil;
+import com.vaadin.client.communication.MessageSender.ResynchronizationState;
 import com.vaadin.client.flow.ConstantPool;
 import com.vaadin.client.flow.StateNode;
 import com.vaadin.client.flow.StateTree;

From f08248dfea3ba25a13e70134f09dcf78c1f1dd4c Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 16:07:46 +0300
Subject: [PATCH 12/20] Add import

---
 .../com/vaadin/client/communication/RequestResponseTracker.java  | 1 +
 1 file changed, 1 insertion(+)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java b/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
index b2d3db2fc9f..58a90eea9ac 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
@@ -20,6 +20,7 @@
 import com.google.web.bindery.event.shared.EventBus;
 import com.google.web.bindery.event.shared.HandlerRegistration;
 
+import com.vaadin.client.communication.MessageSender.ResynchronizationState;
 import com.vaadin.client.ConnectionIndicator;
 import com.vaadin.client.Registry;
 import com.vaadin.client.gwt.com.google.web.bindery.event.shared.SimpleEventBus;

From 356ac9cf3bdfa05d594ec36406bbc4f5a60918b1 Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 16:12:17 +0300
Subject: [PATCH 13/20] Fix

---
 .../java/com/vaadin/client/communication/MessageSender.java     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
index 30ae88423c7..e05667541c0 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
@@ -232,7 +232,7 @@ public String getCommunicationMethodName() {
      */
     public void resynchronize() {
         Console.log("Resynchronize from server requested");
-        resynchronizeRequested = true;
+        resynchronizationState = ResynchronizationState.SEND_TO_SERVER;
         sendInvocationsToServer();
     }
 

From 0559fb992a383cb49b8846b51e1f53a9e9abcf6e Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 16:47:32 +0300
Subject: [PATCH 14/20] Add mock MessageSender

---
 .../test-gwt/java/com/vaadin/client/flow/dom/GwtDomApiTest.java  | 1 +
 1 file changed, 1 insertion(+)

diff --git a/flow-client/src/test-gwt/java/com/vaadin/client/flow/dom/GwtDomApiTest.java b/flow-client/src/test-gwt/java/com/vaadin/client/flow/dom/GwtDomApiTest.java
index 2e8dfad04ae..a9e793dd573 100644
--- a/flow-client/src/test-gwt/java/com/vaadin/client/flow/dom/GwtDomApiTest.java
+++ b/flow-client/src/test-gwt/java/com/vaadin/client/flow/dom/GwtDomApiTest.java
@@ -29,6 +29,7 @@ protected void gwtSetUp() throws Exception {
                 set(RequestResponseTracker.class,
                         new RequestResponseTracker(this));
                 set(MessageHandler.class, new MessageHandler(this));
+                set(MessageSender.class, new MessageSender(this));
                 set(ServerRpcQueue.class, new ServerRpcQueue(this));
                 set(DependencyLoader.class, new DependencyLoader(this));
                 set(ResourceLoader.class, new ResourceLoader(this, false));

From f6d3fb7ea784e4a75a77fc4afc85896bd60913aa Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 16:52:55 +0300
Subject: [PATCH 15/20] Add mock RequestResponseTracker

---
 .../test-gwt/java/com/vaadin/client/GwtMessageHandlerTest.java  | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/flow-client/src/test-gwt/java/com/vaadin/client/GwtMessageHandlerTest.java b/flow-client/src/test-gwt/java/com/vaadin/client/GwtMessageHandlerTest.java
index 30264e7026f..ba204917267 100644
--- a/flow-client/src/test-gwt/java/com/vaadin/client/GwtMessageHandlerTest.java
+++ b/flow-client/src/test-gwt/java/com/vaadin/client/GwtMessageHandlerTest.java
@@ -188,6 +188,8 @@ protected void gwtSetUp() throws Exception {
                 set(ApplicationConfiguration.class,
                         new TestApplicationConfiguration());
                 set(EventsOrder.class, new EventsOrder());
+                set(RequestResponseTracker.class,
+                        new RequestResponseTracker(this));
                 set(MessageSender.class, new TestMessageSender(this));
                 set(SystemErrorHandler.class, new TestSystemErrorHandler(this));
                 set(ExecuteJavaScriptProcessor.class,

From 70a0f3b806bfefbe53c3a8cd20d062e8041e4bfc Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 16:55:26 +0300
Subject: [PATCH 16/20] Add import

---
 .../test-gwt/java/com/vaadin/client/flow/dom/GwtDomApiTest.java  | 1 +
 1 file changed, 1 insertion(+)

diff --git a/flow-client/src/test-gwt/java/com/vaadin/client/flow/dom/GwtDomApiTest.java b/flow-client/src/test-gwt/java/com/vaadin/client/flow/dom/GwtDomApiTest.java
index a9e793dd573..349d7afb61b 100644
--- a/flow-client/src/test-gwt/java/com/vaadin/client/flow/dom/GwtDomApiTest.java
+++ b/flow-client/src/test-gwt/java/com/vaadin/client/flow/dom/GwtDomApiTest.java
@@ -10,6 +10,7 @@
 import com.vaadin.client.UILifecycle.UIState;
 import com.vaadin.client.ValueMap;
 import com.vaadin.client.communication.MessageHandler;
+import com.vaadin.client.communication.MessageSender;
 import com.vaadin.client.communication.RequestResponseTracker;
 import com.vaadin.client.communication.ServerRpcQueue;
 

From f5855b3f3cd8f60cbd5049a72e4e23fa4f80dede Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Thu, 12 May 2022 17:08:03 +0300
Subject: [PATCH 17/20] Fix

---
 .../test-gwt/java/com/vaadin/client/GwtMessageHandlerTest.java  | 2 --
 1 file changed, 2 deletions(-)

diff --git a/flow-client/src/test-gwt/java/com/vaadin/client/GwtMessageHandlerTest.java b/flow-client/src/test-gwt/java/com/vaadin/client/GwtMessageHandlerTest.java
index ba204917267..30264e7026f 100644
--- a/flow-client/src/test-gwt/java/com/vaadin/client/GwtMessageHandlerTest.java
+++ b/flow-client/src/test-gwt/java/com/vaadin/client/GwtMessageHandlerTest.java
@@ -188,8 +188,6 @@ protected void gwtSetUp() throws Exception {
                 set(ApplicationConfiguration.class,
                         new TestApplicationConfiguration());
                 set(EventsOrder.class, new EventsOrder());
-                set(RequestResponseTracker.class,
-                        new RequestResponseTracker(this));
                 set(MessageSender.class, new TestMessageSender(this));
                 set(SystemErrorHandler.class, new TestSystemErrorHandler(this));
                 set(ExecuteJavaScriptProcessor.class,

From f27beb497cd96d419c29f282324b6e109909101d Mon Sep 17 00:00:00 2001
From: Tatu Lund <tatu@vaadin.com>
Date: Fri, 13 May 2022 10:39:09 +0300
Subject: [PATCH 18/20] Code formatting

---
 .../vaadin/client/communication/RequestResponseTracker.java    | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java b/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
index 58a90eea9ac..3a3750cf0e4 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/RequestResponseTracker.java
@@ -111,7 +111,8 @@ public void endRequest() {
 
         if ((registry.getUILifecycle().isRunning()
                 && registry.getServerRpcQueue().isFlushPending())
-                || registry.getMessageSender().getResynchronizationState() == ResynchronizationState.SEND_TO_SERVER) {
+                || registry.getMessageSender()
+                        .getResynchronizationState() == ResynchronizationState.SEND_TO_SERVER) {
             // Send the pending RPCs immediately.
             // This might be an unnecessary optimization as ServerRpcQueue has a
             // finally scheduled command which trigger the send if we do not do

From b8b393a3859df46860cb4384d97b9d39e21efc19 Mon Sep 17 00:00:00 2001
From: Mikhail Shabarov <mikhail@vaadin.com>
Date: Wed, 18 May 2022 16:42:54 +0300
Subject: [PATCH 19/20] fix: Ask for resynchronization before end a previous
 request

---
 .../client/communication/MessageHandler.java  | 22 +++++++------
 .../client/communication/MessageSender.java   | 31 ++++++++++++++++---
 2 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
index b888a8fa536..09ab36df996 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
@@ -227,8 +227,7 @@ protected void handleJSON(final ValueMap valueMap) {
             return;
         }
 
-        registry.getMessageSender()
-                .setResynchronizationState(ResynchronizationState.NOT_ACTIVE);
+        registry.getMessageSender().clearResynchronizationState();
 
         if (hasResynchronize && !isNextExpectedMessage(serverId)) {
             // Resynchronize request. We must remove any old pending
@@ -579,13 +578,6 @@ private int getExpectedServerId() {
     }
 
     private void forceMessageHandling() {
-        // Clear previous request if it exists. Otherwise resyncrhonize can
-        // trigger
-        // "Trying to start a new request while another is active" exception and
-        // fail.
-        if (registry.getRequestResponseTracker().hasActiveRequest()) {
-            registry.getRequestResponseTracker().endRequest();
-        }
         if (!responseHandlingLocks.isEmpty()) {
             // Lock which was never release -> bug in locker or things just
             // too slow
@@ -606,6 +598,18 @@ private void forceMessageHandling() {
             // has been lost
             // Drop pending messages and resynchronize
             pendingUIDLMessages.clear();
+
+            // Inform the message sender that resynchronize is desired already
+            // since endRequest may already send out a next request
+            registry.getMessageSender().requestResynchronize();
+
+            // Clear previous request if it exists.
+            if (registry.getRequestResponseTracker().hasActiveRequest()) {
+                registry.getRequestResponseTracker().endRequest();
+            }
+
+            // Call resynchronize to make sure a resynchronize request is sent in
+            // case endRequest did not already do this.
             registry.getMessageSender().resynchronize();
         }
     }
diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
index e05667541c0..4e89be4e6c0 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
@@ -231,9 +231,9 @@ public String getCommunicationMethodName() {
      * state from the server
      */
     public void resynchronize() {
-        Console.log("Resynchronize from server requested");
-        resynchronizationState = ResynchronizationState.SEND_TO_SERVER;
-        sendInvocationsToServer();
+        if (requestResynchronize()) {
+            sendInvocationsToServer();
+        }
     }
 
     /**
@@ -276,8 +276,29 @@ public void setClientToServerMessageId(int nextExpectedId, boolean force) {
         }
     }
 
-    void setResynchronizationState(ResynchronizationState state) {
-        resynchronizationState = state;
+    /**
+     * Modifies the resynchronize state to indicate that resynchronization is desired
+     *
+     * @return true if the resynchronize request still needs to be sent; false otherwise
+     */
+    boolean requestResynchronize() {
+        switch (resynchronizationState) {
+            case NOT_ACTIVE:
+                Console.log("Resynchronize from server requested");
+                resynchronizationState = ResynchronizationState.SEND_TO_SERVER;
+                return true;
+            case SEND_TO_SERVER:
+                // Resynchronize has already been requested, but hasn't been sent yet
+                return true;
+            case WAITING_FOR_RESPONSE:
+            default:
+                // Resynchronize has already been requested, but response hasn't been received yet
+                return false;
+        }
+    }
+
+    void clearResynchronizationState() {
+        resynchronizationState = ResynchronizationState.NOT_ACTIVE;
     }
 
     ResynchronizationState getResynchronizationState() {

From 7d982492afafc8b24659ace238c5d7de0a6021da Mon Sep 17 00:00:00 2001
From: Mikhail Shabarov <mikhail@vaadin.com>
Date: Wed, 18 May 2022 16:54:40 +0300
Subject: [PATCH 20/20] chore: fix formatting

---
 .../client/communication/MessageHandler.java  |  3 +-
 .../client/communication/MessageSender.java   | 30 +++++++++++--------
 2 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
index 09ab36df996..55bfef8b259 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageHandler.java
@@ -608,7 +608,8 @@ private void forceMessageHandling() {
                 registry.getRequestResponseTracker().endRequest();
             }
 
-            // Call resynchronize to make sure a resynchronize request is sent in
+            // Call resynchronize to make sure a resynchronize request is sent
+            // in
             // case endRequest did not already do this.
             registry.getMessageSender().resynchronize();
         }
diff --git a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
index 4e89be4e6c0..4a01392237f 100644
--- a/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
+++ b/flow-client/src/main/java/com/vaadin/client/communication/MessageSender.java
@@ -277,23 +277,27 @@ public void setClientToServerMessageId(int nextExpectedId, boolean force) {
     }
 
     /**
-     * Modifies the resynchronize state to indicate that resynchronization is desired
+     * Modifies the resynchronize state to indicate that resynchronization is
+     * desired
      *
-     * @return true if the resynchronize request still needs to be sent; false otherwise
+     * @return true if the resynchronize request still needs to be sent; false
+     *         otherwise
      */
     boolean requestResynchronize() {
         switch (resynchronizationState) {
-            case NOT_ACTIVE:
-                Console.log("Resynchronize from server requested");
-                resynchronizationState = ResynchronizationState.SEND_TO_SERVER;
-                return true;
-            case SEND_TO_SERVER:
-                // Resynchronize has already been requested, but hasn't been sent yet
-                return true;
-            case WAITING_FOR_RESPONSE:
-            default:
-                // Resynchronize has already been requested, but response hasn't been received yet
-                return false;
+        case NOT_ACTIVE:
+            Console.log("Resynchronize from server requested");
+            resynchronizationState = ResynchronizationState.SEND_TO_SERVER;
+            return true;
+        case SEND_TO_SERVER:
+            // Resynchronize has already been requested, but hasn't been sent
+            // yet
+            return true;
+        case WAITING_FOR_RESPONSE:
+        default:
+            // Resynchronize has already been requested, but response hasn't
+            // been received yet
+            return false;
         }
     }