Bug 144556 [Dialogs] TitleAreaDialog fails to properly recreate when an instance is reopened
When a TitleAreaDialog is created, opened, closed and opened again on the same instance the messageArea is not properly checked against disposal when it is accessed in setWarningMessage throwing an SWTException for disposed when the message area is updated the second time the dialog is opened.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/TitleAreaDialog.java
/**
     * Sets the title bar color for this dialog.
     * 
     * @param color
     *            the title bar color
     */
    public void setTitleAreaColor(RGB color) {
        titleAreaRGB = color;
    }
    /**
     * Sets the title image to be shown in the title area of this dialog.
     * 
     * @param newTitleImage
     *            the title image to be shown
     */
    public void setTitleImage(Image newTitleImage) {
    	titleImage = newTitleImage;
    	
    	
    	if (titleImageLabel != null && !titleImageLabel.isDisposed()) {
    		titleImageLabel.setImage(newTitleImage);
    		titleImageLabel.setVisible(newTitleImage != null);
    		if (newTitleImage != null) {
    			resetWorkAreaAttachments(titleArea);
    		}
    	}
    }
    /**
     * Make the label used for displaying error images visible depending on
     * boolean.