8309460: JScrollBar leaves behind clutter for non-integer UI scales

src/java.desktop/share/classes/javax/swing/plaf/basic/BasicScrollBarUI.java

@@ -1179,6 +1179,7 @@ else if (delta < 0 && newValue > oldValue) {
                 }
             }
             scrollbar.setValue(newValue);
+
         }
     }
 
@@ -1188,6 +1189,8 @@ else if (delta < 0 && newValue > oldValue) {
      */
     protected void scrollByUnit(int direction)  {
         scrollByUnits(scrollbar, direction, 1, false);
+        Rectangle r = getTrackBounds();
+        scrollbar.repaint(r.x, r.y, r.width, r.height);
     }
 
     /**
@@ -1376,6 +1379,8 @@ public void mouseDragged(MouseEvent e) {
                 updateThumbState(currentMouseX, currentMouseY);
                 startScrollTimerIfNecessary();
             }
+            Rectangle r = getTrackBounds();
+            scrollbar.repaint(r.x, r.y, r.width, r.height);
         }
 
         private void setValueFrom(MouseEvent e) {

test/jdk/javax/swing/JScrollBar/JScrollBarArtifactTest.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.awt.BorderLayout;
+import javax.swing.JFrame;
+import javax.swing.JPanel;
+import javax.swing.JScrollBar;
+import javax.swing.SwingUtilities;
+
+/*
+ * @test
+ * @bug 8309460
+ * @summary Verifies clicking JComboBox during frame closure causes Exception
+ * @library /java/awt/regtesthelpers
+ * @build PassFailJFrame
+ * @run main/manual JScrollBarArtifactTest
+ */
+
+public class JScrollBarArtifactTest {
+    private static final String instructionsText = """
+            This test is used to verify that dragging scrollbar or clicking
+            on right scrollbar thumb does nto leave behing lines or artifacts.
+
+            A horizontal JScrollBar is shown.
+            Drag the scrollbar without releasing mouse.
+            Additionally, keep right arrow button pressed to move the scrollbar.
+            If lines are left behind in both cases, please click Fail 
+            otherwise click Pass.  """;
+
+    public static void main(String[] args) throws Exception {
+        System.setProperty("sun.java2d.uiScale", "2.3");
+        PassFailJFrame passFailJFrame = new PassFailJFrame.Builder()
+                .title("ComboPopup Instructions")
+                .instructions(instructionsText)
+                .testTimeOut(5)
+                .rows(10)
+                .columns(35)
+                .build();
+
+        SwingUtilities.invokeAndWait(() -> {
+            JFrame frame = new JFrame();
+            JPanel panel = new JPanel(new BorderLayout());
+            JScrollBar sb = new JScrollBar(JScrollBar.HORIZONTAL);
+            panel.add(sb, "South");
+            frame.setContentPane(panel);
+            frame.setSize(500, 200);
+
+            PassFailJFrame.addTestWindow(frame);
+            PassFailJFrame.positionTestWindow(frame,
+                    PassFailJFrame.Position.VERTICAL);
+
+            frame.setVisible(true);
+        });
+
+        passFailJFrame.awaitAndCheck();
+    }
+}
+