FULL PRODUCT VERSION :
java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
Java HotSpot(TM) Client VM (build 1.5.0_06-b05, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
javax.swing.JScrollPane lines 1477 and 1488 read:

if (propertyName == "horizontalScrollBar" ||
propertyName == "verticalScrollBar") {

This represents an incorrect application of the == operator; the expression will always evaluate to false. Please replace it with:

if ((propertyName != null) && (propertyName.equals("horizontalScrollBar") ||
propertyName.equals("verticalScrollBar"))) {

How does Sun Microsystems justify the employment of engineers who fail to understand the basic usage of Java language operators? The Java development community would greatly appreciate more stringent enforcement of basic software design and development skills amongst the Swing team members. Their elementary errors have cost us all a vast amount of both time and money.


REPRODUCIBILITY :
This bug can be reproduced always.