Bug 125327 [Dialogs] Error message shown in the InputDialog is not fully visible
When an error message returned by InputValidator is long, InputDialog displays it partially. My suggestion is to create error label with SWT.WRAP flag, or something like this.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/InputDialog.java
*            the dialog title, or <code>null</code> if none
     * @param dialogMessage
     *            the dialog message, or <code>null</code> if none
     * @param initialValue
     *            the initial input value, or <code>null</code> if none
     *            (equivalent to the empty string)
     * @param validator
     *            an input validator, or <code>null</code> if none
     */
    public InputDialog(Shell parentShell, String dialogTitle,
            String dialogMessage, String initialValue, IInputValidator validator) {
        super(parentShell);
        this.title = dialogTitle;
        message = dialogMessage;
        if (initialValue == null) {
			value = "";
		} else {
			value = initialValue;
		}
        this.validator = validator;
    }
    /*
     * (non-Javadoc) Method declared on Dialog.
     */
    protected void buttonPressed(int buttonId) {
        if (buttonId == IDialogConstants.OK_ID) {
            value = text.getText();
        } else {
            value = null;
        }