Fix bookkeeping assertion error

Fixes #9584

3 files changed, 25 insertions, 1 deletions

diff --git a/server/src/main/java/com/vaadin/data/provider/DataCommunicator.java b/server/src/main/java/com/vaadin/data/provider/DataCommunicator.java
index 0971c36755..054e86ca8d 100644
--- a/server/src/main/java/com/vaadin/data/provider/DataCommunicator.java
+++ b/server/src/main/java/com/vaadin/data/provider/DataCommunicator.java
@@ -185,6 +185,7 @@ public class DataCommunicator<T> extends AbstractExtension {
 
         @Override
         public void destroyAllData() {
+            droppedData.clear();
             activeData.clear();
             getKeyMapper().removeAll();
         }
diff --git a/server/src/test/java/com/vaadin/data/provider/DataCommunicatorTest.java b/server/src/test/java/com/vaadin/data/provider/DataCommunicatorTest.java
index 1e75d57263..c6d80e6ab0 100644
--- a/server/src/test/java/com/vaadin/data/provider/DataCommunicatorTest.java
+++ b/server/src/test/java/com/vaadin/data/provider/DataCommunicatorTest.java
@@ -18,6 +18,8 @@ package com.vaadin.data.provider;
 import java.util.Collections;
 import java.util.concurrent.Future;
 
+import elemental.json.Json;
+import elemental.json.JsonArray;
 import org.junit.Assert;
 import org.junit.Test;
 import org.mockito.Mockito;
@@ -191,4 +193,25 @@ public class DataCommunicatorTest {
                 TEST_OBJECT, generator.generated);
     }
 
+    @Test
+    public void testDestroyData() {
+        session.lock();
+        UI ui = new TestUI(session);
+        TestDataCommunicator communicator = new TestDataCommunicator();
+        TestDataProvider dataProvider = new TestDataProvider();
+        communicator.setDataProvider(dataProvider, null);
+        communicator.extend(ui);
+        // Put a test object into a cache
+        communicator.pushData(1, Collections.singletonList(TEST_OBJECT));
+        // Drop the test object from the cache
+        String key = communicator.getKeyMapper().key(TEST_OBJECT);
+        JsonArray keys = Json.createArray();
+        keys.set(0,key);
+        communicator.onDropRows(keys);
+        // Drop everything
+        communicator.dropAllData();
+        // The communicator does not have to throw exceptions during
+        // request finalization
+        communicator.beforeClientResponse(false);
+    }
 }
diff --git a/shared/src/main/java/com/vaadin/shared/Range.java b/shared/src/main/java/com/vaadin/shared/Range.java
index 49458d848b..3f670ca28c 100644
--- a/shared/src/main/java/com/vaadin/shared/Range.java
+++ b/shared/src/main/java/com/vaadin/shared/Range.java
@@ -229,7 +229,7 @@ public final class Range implements Serializable {
     @Override
     public String toString() {
         return getClass().getSimpleName() + " [" + getStart() + ".." + getEnd()
-                + "[" + (isEmpty() ? " (empty)" : "");
+                + "]" + (isEmpty() ? " (empty)" : "");
     }
 
     @Override