Bug 182190 [StatusHandling] [Wizards] getControl assert on wizard page has no message
M6 If you forget to set the control on your wizard page our assert gives no feedback. We need an error message.
bundles/org.eclipse.jface/src/org/eclipse/jface/wizard/WizardDialog.java
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.jface.dialogs.ControlEnableState;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.IMessageProvider;
import org.eclipse.jface.dialogs.IPageChangeProvider;
import org.eclipse.jface.dialogs.IPageChangedListener;
import org.eclipse.jface.dialogs.IPageChangingListener;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.dialogs.PageChangedEvent;
import org.eclipse.jface.dialogs.PageChangingEvent;
import org.eclipse.jface.dialogs.TitleAreaDialog;
import org.eclipse.jface.operation.IRunnableWithProgress;
import org.eclipse.jface.operation.ModalContext;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.util.SafeRunnable;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.swt.events.HelpEvent;
import org.eclipse.swt.events.HelpListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Cursor;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;