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
fireValueChange(Diffs.createValueDiff(oldValue,
								newValue));
					}
				} else {
					fireValueChange(Diffs.createValueDiff(oldValue, text
							.getText()));
				}
			}
		}
	};
	private VerifyListener verifyListener;
	private KeyListener keyListener;
	/**
	 * @param text
	 * @param updatePolicy
	 */
	public TextObservableValue(final Text text, int updatePolicy) {
		this.text = text;
		this.updatePolicy = updatePolicy;
		if (updatePolicy != SWT.None) {
			text.addListener(updatePolicy, updateListener);
		}
		
		
		
		
		
		
		if (updatePolicy == SWT.Modify) {
			text.addListener(SWT.FocusOut, new Listener() {