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 #setPreferenceStore
	 */
	private IPreferenceStore preferenceStore;
	private boolean showingError = false;
	private Composite titleArea;
	private Color titleAreaColor;
	private Label titleImage;
	/**
	 * The tree viewer.
	 */
	private TreeViewer treeViewer;
	/**
	 * Creates a new preference dialog under the control of the given preference 
	 * manager.
	 *
	 * @param shell the parent shell
	 * @param manager the preference manager
	 */
	public PreferenceDialog(Shell parentShell, PreferenceManager manager) {
		super(parentShell);
		setShellStyle(getShellStyle() | SWT.RESIZE | SWT.MAX);
		preferenceManager = manager;
	}
	/* (non-Javadoc)
	 * @see org.eclipse.jface.dialogs.Dialog#buttonPressed(int)
	 */
	protected void buttonPressed(int buttonId) {
		switch (buttonId) {
			case IDialogConstants.OK_ID :
				{