Removed outdated spacer height update from removal process. (#11861)

* Removed outdated spacer height update from removal process.

Fixes #11856

client/src/main/java/com/vaadin/client/widgets/Grid.java

@@ -3901,8 +3901,6 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
                 setParent(detailsWidget, null);
                 spacerElement.removeAllChildren();
                 if (getHeightMode() == HeightMode.UNDEFINED) {
-                    // update spacer height
-                    escalator.getBody().setSpacer(spacer.getRow(), 0);
                     setHeightByRows(getEscalator().getBody().getRowCount());
                 }
             }

uitest/src/main/java/com/vaadin/tests/components/grid/GridDetailsAndUndefinedHeight.java

@@ -0,0 +1,76 @@
+package com.vaadin.tests.components.grid;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Set;
+import java.util.stream.IntStream;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.shared.ui.grid.HeightMode;
+import com.vaadin.tests.components.AbstractReindeerTestUI;
+import com.vaadin.tests.data.bean.Person;
+import com.vaadin.ui.Grid;
+import com.vaadin.ui.Grid.SelectionMode;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.VerticalLayout;
+
+public class GridDetailsAndUndefinedHeight extends AbstractReindeerTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        ArrayList<Person> itemsCollection = new ArrayList<>();
+
+        final Grid<Person> grid = new Grid<Person>() {
+            @Override
+            public void setItems(Collection<Person> items) {
+                itemsCollection.clear();
+                itemsCollection.addAll(items);
+                super.setItems(items);
+            }
+        };
+        addComponent(grid);
+
+        grid.addColumn(Person::getFirstName);
+        grid.addColumn(Person::getLastName);
+        grid.addColumn(Person::getEmail);
+
+        grid.setItems(IntStream.range(0, 5).mapToObj(this::createPerson));
+
+        grid.setWidthFull();
+        grid.setHeightMode(HeightMode.UNDEFINED);
+
+        grid.setSelectionMode(SelectionMode.SINGLE);
+
+        grid.addSelectionListener(event -> {
+            itemsCollection
+                    .forEach(item -> grid.setDetailsVisible(item, false));
+            final Set<Person> selections = event.getAllSelectedItems();
+            if (!selections.isEmpty()) {
+                Person selection = selections.iterator().next();
+                grid.setDetailsVisible(selection, true);
+                grid.scrollTo(itemsCollection.indexOf(selection));
+            }
+        });
+        grid.setDetailsGenerator(person -> new VerticalLayout(
+                new Label("Details " + itemsCollection.indexOf(person))));
+    }
+
+    private Person createPerson(int index) {
+        Person person = new Person();
+        person.setFirstName("cell " + index + " 0");
+        person.setLastName("cell " + index + " 1");
+        person.setEmail("cell " + index + " 2");
+        return person;
+    }
+
+    @Override
+    protected String getTestDescription() {
+        return "Second selection should successfully close "
+                + "the details row from the first selection.";
+    }
+
+    @Override
+    protected Integer getTicketNumber() {
+        return 11856;
+    }
+}

uitest/src/test/java/com/vaadin/tests/components/grid/GridDetailsAndUndefinedHeightTest.java

@@ -0,0 +1,39 @@
+package com.vaadin.tests.components.grid;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.List;
+
+import org.junit.Test;
+import org.openqa.selenium.WebElement;
+
+import com.vaadin.testbench.By;
+import com.vaadin.testbench.elements.GridElement;
+import com.vaadin.tests.tb3.MultiBrowserTest;
+
+public class GridDetailsAndUndefinedHeightTest extends MultiBrowserTest {
+
+    @Test
+    public void changingSelectionClosesOldDetails() {
+        openTestURL();
+        GridElement grid = $(GridElement.class).first();
+        grid.getCell(4, 0).click();
+        waitForElementPresent(By.className("v-grid-spacer"));
+
+        List<WebElement> spacers = grid
+                .findElements(By.className("v-grid-spacer"));
+        assertEquals("Unexpected amount of details rows", 1, spacers.size());
+        assertEquals("Unexpected details row contents", "Details 4",
+                spacers.get(0).findElement(By.className("v-label")).getText());
+
+        // change selection
+        grid.getCell(3, 0).click();
+
+        spacers = grid.findElements(By.className("v-grid-spacer"));
+        assertEquals("Unexpected amount of details rows", 1, spacers.size());
+        assertEquals("Unexpected details row contents", "Details 3",
+                spacers.get(0).findElement(By.className("v-label")).getText());
+
+    }
+
+}