Fix combo box suggestion popup height (#10256)

Fixes #10214

client/src/main/java/com/vaadin/client/ui/VComboBox.java

@@ -867,10 +867,18 @@ public class VComboBox extends Composite implements Field, KeyDownHandler,
                     menuHeight -= up.getOffsetHeight() + down.getOffsetHeight()
                             + status.getOffsetHeight();
                 } else {
-                    final ComputedStyle s = new ComputedStyle(
+                    final ComputedStyle menuStyle = new ComputedStyle(
                             menu.getElement());
-                    menuHeight -= s.getIntProperty("marginBottom")
-                            + s.getIntProperty("marginTop");
+                    final ComputedStyle popupStyle = new ComputedStyle(
+                            suggestionPopup.getElement());
+                    menuHeight -= menuStyle.getIntProperty("marginBottom")
+                            + menuStyle.getIntProperty("marginTop")
+                            + menuStyle.getIntProperty("paddingBottom")
+                            + menuStyle.getIntProperty("paddingTop")
+                            + popupStyle.getIntProperty("marginBottom")
+                            + popupStyle.getIntProperty("marginTop")
+                            + popupStyle.getIntProperty("paddingBottom")
+                            + popupStyle.getIntProperty("paddingTop");
                 }
 
                 // If the available page height is really tiny then this will be

uitest/src/main/java/com/vaadin/tests/components/combobox/ComboBoxHeight.java

@@ -0,0 +1,25 @@
+package com.vaadin.tests.components.combobox;
+
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import com.vaadin.annotations.Widgetset;
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.tests.components.AbstractTestUI;
+import com.vaadin.ui.ComboBox;
+
+@Widgetset("com.vaadin.DefaultWidgetSet")
+public class ComboBoxHeight extends AbstractTestUI {
+
+    @Override
+    protected void setup(VaadinRequest request) {
+        ComboBox<String> comboBox = new ComboBox<>();
+        comboBox.setPageLength(0);
+        comboBox.setItems(
+                IntStream.range(0, 100)
+                        .mapToObj(i -> "Item number " + String.valueOf(i))
+                        .collect(Collectors.toList()));
+
+        addComponent(comboBox);
+    }
+}

uitest/src/main/themes/VAADIN/themes/tests-valo-combobox-height/_variables.scss

@@ -0,0 +1,4 @@
+$v-selection-overlay-padding-vertical: 10px;
+$v-selection-overlay-padding-horizontal: 10px;
+
+@import "../valo/valo";

uitest/src/main/themes/VAADIN/themes/tests-valo-combobox-height/styles.scss

@@ -0,0 +1,13 @@
+@import "variables";
+@import "../tests-valo/valotest";
+
+.tests-valo-combobox-height {
+   @include valotest;
+
+   .v-filterselect-suggestpopup {
+      margin-top: 10px !important;
+      margin-bottom: 10px;
+      padding-top: 5px;
+      padding-bottom: 5px;
+   }
+}

uitest/src/test/java/com/vaadin/tests/components/combobox/ComboBoxHeightTest.java

@@ -0,0 +1,38 @@
+package com.vaadin.tests.components.combobox;
+
+import org.junit.Test;
+import org.openqa.selenium.WebElement;
+
+import com.vaadin.testbench.elements.ComboBoxElement;
+import com.vaadin.tests.tb3.SingleBrowserTest;
+
+public class ComboBoxHeightTest extends SingleBrowserTest {
+
+    @Test
+    public void testPopupHeight() {
+        openTestURL();
+        assertPopupHeight();
+    }
+
+    @Test
+    public void testPopupHeightCustomTheme() {
+        openTestURL("theme=tests-valo-combobox-height");
+        assertPopupHeight();
+    }
+
+    private void assertPopupHeight() {
+        ComboBoxElement comboBox = $(ComboBoxElement.class).first();
+
+        comboBox.openPopup();
+        WebElement suggestionPopup = comboBox.getSuggestionPopup();
+
+        int suggestionPopupBottom =
+                suggestionPopup.getLocation().getY() + suggestionPopup.getSize()
+                        .getHeight();
+
+        assertGreaterOrEqual(
+                "Combo box suggestion popup should not exceed the browser's viewport",
+                driver.manage().window().getSize().getHeight(),
+                suggestionPopupBottom);
+    }
+}