Bug 49274 [Activities] Cannot open preference dialog if previous selected node not in fitlered list
M6 You cannot open the preference dialog if the previously selected preference is in the filtered list due to a walkback STEPS 1) Open the preference dialog 2) Select a raw entry that is not in the filtered list 3) Cancel 4) Attempt to reopen - it will try to select a non-esistant node. It should just drop the selection if it isn't there (or not save a selection from the raw list to start with). org.eclipse.jface.util.Assert$AssertionFailedException: Assertion failed: at org.eclipse.jface.util.Assert.isTrue(Assert.java:168) at org.eclipse.jface.util.Assert.isTrue(Assert.java:154) at org.eclipse.jface.preference.PreferenceNode.findSubNode (PreferenceNode.java:177) at org.eclipse.jface.preference.PreferenceContentProvider.findParent (PreferenceContentProvider.java:42) at org.eclipse.jface.preference.PreferenceContentProvider.getParent (PreferenceContentProvider.java:80) at org.eclipse.jface.viewers.AbstractTreeViewer.internalExpand (AbstractTreeViewer.java:893) at org.eclipse.jface.viewers.AbstractTreeViewer.internalExpand (AbstractTreeViewer.java:895) at org.eclipse.jface.viewers.AbstractTreeViewer.internalExpand (AbstractTreeViewer.java:895) at org.eclipse.jface.viewers.AbstractTreeViewer.setSelectionToWidget (AbstractTreeViewer.java:1370) at org.eclipse.jface.viewers.StructuredViewer.setSelectionToWidget (StructuredViewer.java:1066) at org.eclipse.jface.viewers.StructuredViewer.setSelection (StructuredViewer.java:1031) at org.eclipse.jface.preference.PreferenceDialog.selectSavedItem (PreferenceDialog.java:818) at org.eclipse.jface.preference.PreferenceDialog$3.run (PreferenceDialog.java:332) at org.eclipse.swt.custom.BusyIndicator.showWhile (BusyIndicator.java:84) at org.eclipse.jface.preference.PreferenceDialog.createContents (PreferenceDialog.java:327) at org.eclipse.jface.window.Window.create(Window.java:305) at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:883) at org.eclipse.ui.internal.OpenPreferencesAction.run (OpenPreferencesAction.java:70) at org.eclipse.jface.action.Action.runWithEvent(Action.java:842) at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection (ActionContributionItem.java:509) at org.eclipse.jface.action.ActionContributionItem.access$2 (ActionContributionItem.java:461) at org.eclipse.jface.action.ActionContributionItem$5.handleEvent (ActionContributionItem.java:408) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:82) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:847) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:2311) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:1992) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:1506) at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:1482) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench (Workbench.java:246) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:139) at org.eclipse.ui.internal.ide.IDEApplication.run (IDEApplication.java:47) at org.eclipse.core.internal.runtime.PlatformActivator$1.run (PlatformActivator.java:226) at org.eclipse.core.runtime.adaptor.EclipseStarter.run (EclipseStarter.java:85) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:324) at org.eclipse.core.launcher.Main.basicRun(Main.java:279) at org.eclipse.core.launcher.Main.run(Main.java:742) at org.eclipse.core.launcher.Main.main(Main.java:581)
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
* @see #setHelpAvailable
	 */
	private boolean isHelpAvailable = false;
	private Point lastShellSize;
	private IPreferenceNode lastSuccessfulNode;
	private String message = ""; 
	private Image messageImage;
	private CLabel messageLabel;
	/**
	 * The minimum page size; 400 by 400 by default.
	 *
	 * @see #setMinimumPageSize
	 */
	private Point minimumPageSize = new Point(400, 400);
	private Color normalMsgAreaBackground;
	/**
	 * The OK button.
	 */
	private Button okButton;
	/**
	 * The Composite in which a page is shown.
	 */
	private Composite pageContainer;
	/**
	 * The preference manager.
	 */
	private PreferenceManager preferenceManager;
	/**
	 * Preference store, initially <code>null</code> meaning none.
	 *