8328540: test javax/swing/JSplitPane/4885629/bug4885629.java fails on…

… windows hidpi

Backport-of: fa823bd21c6676c67c42275efb59868200409b38

test/jdk/javax/swing/JSplitPane/4885629/bug4885629.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 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
@@ -104,9 +104,9 @@ public void run() {
 
                     SwingUtilities.convertPointToScreen(p, sp);
 
-                    for (int i = 0; i < rect.width; i++) {
+                    for (int i = 1; i < rect.width - 1; i++) {
                         if (!BGCOLOR.equals(robot.getPixelColor(p.x + i, p.y + rect.height - 1))) {
-                            throw new Error("The divider's area has incorrect color.");
+                            throw new Error("The divider's area has incorrect color. i=" + i);
                         }
                     }
                 }