Bug 137073 [Preferences] Encoding field editor never fires value change events
The class AbstractEncodingFieldEditor never fires VALUE property change events unless the validaty of the value has also changed. I will attach a patch that corrects the problem.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/AbstractEncodingFieldEditor.java
*            (by default a {@link Composite} instead of a {@link Group}.
	 * @param parent
	 *            the parent of the field editor's control
	 * @see AbstractEncodingFieldEditor#setGroupTitle(String)
	 * @since 3.3
	 */
	protected AbstractEncodingFieldEditor(String name, String labelText,
			String groupTitle, Composite parent) {
		init(name, labelText);
		this.groupTitle = groupTitle;
		createControl(parent);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.preference.FieldEditor#adjustForNumColumns(int)
	 */
	protected void adjustForNumColumns(int numColumns) {
		((GridData) getContainer().getLayoutData()).horizontalSpan = numColumns;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.preference.FieldEditor#doFillIntoGrid(org.eclipse.swt.widgets.Composite,
	 *      int)
	 */
	protected void doFillIntoGrid(Composite parent, int numColumns) {
		container = createEncodingGroup(parent, numColumns);
	}
	/*