Bug 134750 [DataBinding] TextObservableValue throws NPE on change if the intial model value is null
When binding a Text to a model attribute that has an intial value of null ObservableTextValue throws a NPE when updating the view. In "updateListener" it assumes that oldValue != null. I'll attach a JUnit that throws the Exception.
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/internal/swt/TextObservableValue.java
private final Text text;
	private boolean updating = false;
	private int updatePolicy;
	private String bufferedValue;
	private Listener updateListener = new Listener() {
		public void handleEvent(Event event) {
			if (!updating) {
				String oldValue = bufferedValue;
				String newValue = text.getText();
				
				
				if (updatePolicy == SWT.FocusOut) {
					bufferedValue = text.getText();
					if (!oldValue.equals(newValue)) {