Bug 6969 NPE in code formatter preference page
20011206 Open the code formatter preference page Go to the style tab Go to the number of spaces... field Backspace until the field is empty NPE
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/CodeFormatterPreferencePage.java
control.setLayoutData(gdata);
		return previewViewer;
	}
	
	private Button addCheckBox(Composite parent, String label, String key, String[] values) {
		ControlData data= new ControlData(key, values);
		
		GridData gd= new GridData(GridData.FILL_HORIZONTAL);
		gd.horizontalSpan= 2;
		
		Button checkBox= new Button(parent, SWT.CHECK);
		checkBox.setText(label);
		checkBox.setData(data);
		checkBox.setLayoutData(gd);
		
		String currValue= (String)fWorkingValues.get(key);	
		checkBox.setSelection(data.getSelection(currValue) == 0);
		checkBox.addSelectionListener(fButtonSelectionListener);
		
		fCheckBoxes.add(checkBox);
		return checkBox;
	}
	
	private Text addTextField(Composite parent, String label, String key) {	
		Label labelControl= new Label(parent, SWT.NONE);
		labelControl.setText(label);
		labelControl.setLayoutData(new GridData());
				
		Text textBox= new Text(parent, SWT.BORDER | SWT.SINGLE);
		textBox.setData(key);