Bug 83440 NullPointerException in refactoring preview dialog
When refactoring a private member class into a top-level class using "Move Member Type to New File...", in the preview dialog, clicking on the name of the class in the preview (to see the detailed changes), or any member of that class nested under it in the tree, causes a NullPointerException. A test case that fails on my machine: public class TestClass { private class TestClass2 { private String x; private int y; } } Doing TestClass2 -> Refactor -> Move Member Type to New File... -> Preview -> Continue -> Open tree to TestClass2 and selecting it or any member variable causes the following NullPointerException: java.lang.NullPointerException at org.eclipse.ltk.core.refactoring.TextChange.getPreviewContent(TextChange.java:599) at org.eclipse.ltk.internal.ui.refactoring.TextChangePreviewViewer.setInput(TextChangePreviewViewer.java:184) at org.eclipse.ltk.internal.ui.refactoring.PseudoJavaChangeElement.feedInput(PseudoJavaChangeElement.java:73) at org.eclipse.ltk.internal.ui.refactoring.PreviewWizardPage.showPreview(PreviewWizardPage.java:376) at org.eclipse.ltk.internal.ui.refactoring.PreviewWizardPage.access$2(PreviewWizardPage.java:355) at org.eclipse.ltk.internal.ui.refactoring.PreviewWizardPage$2.selectionChanged(PreviewWizardPage.java:346) at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java:163) at org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1044) at org.eclipse.core.runtime.Platform.run(Platform.java:747) at org.eclipse.jface.viewers.Viewer.fireSelectionChanged(Viewer.java:161) at org.eclipse.jface.viewers.StructuredViewer.updateSelection(StructuredViewer.java:1667) at org.eclipse.jface.viewers.StructuredViewer.handleSelect(StructuredViewer.java:935) at org.eclipse.jface.viewers.CheckboxTreeViewer.handleSelect(CheckboxTreeViewer.java:268) at org.eclipse.jface.viewers.StructuredViewer$4.widgetSelected(StructuredViewer.java:961) at org.eclipse.jface.util.OpenStrategy.fireSelectionEvent(OpenStrategy.java:209) at org.eclipse.jface.util.OpenStrategy.access$3(OpenStrategy.java:204) at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:364) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:82) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:833) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:2803) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2448) at org.eclipse.jface.window.Window.runEventLoop(Window.java:718) at org.eclipse.jface.window.Window.open(Window.java:696) at org.eclipse.ltk.ui.refactoring.RefactoringWizardOpenOperation$1.run(RefactoringWizardOpenOperation.java:125) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:69) at org.eclipse.ltk.ui.refactoring.RefactoringWizardOpenOperation.run(RefactoringWizardOpenOperation.java:138) at org.eclipse.jdt.internal.ui.refactoring.actions.RefactoringStarter.activate(RefactoringStarter.java:40) at org.eclipse.jdt.ui.actions.ConvertNestedToTopAction.startRefactoring(ConvertNestedToTopAction.java:210) at org.eclipse.jdt.ui.actions.ConvertNestedToTopAction.run(ConvertNestedToTopAction.java:166) at org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun(SelectionDispatchAction.java:216) at org.eclipse.jdt.ui.actions.SelectionDispatchAction.run(SelectionDispatchAction.java:188) at org.eclipse.jface.action.Action.runWithEvent(Action.java:989) at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:555) at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:505) at org.eclipse.jface.action.ActionContributionItem$6.handleEvent(ActionContributionItem.java:419) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:82) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:833) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:2803) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2448) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:1569) at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:1540) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:285) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:144) at org.eclipse.ui.internal.ide.IDEApplication.run(IDEApplication.java:102) at org.eclipse.core.internal.runtime.PlatformActivator$1.run(PlatformActivator.java:220) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:273) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:129) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.eclipse.core.launcher.Main.basicRun(Main.java:185) at org.eclipse.core.launcher.Main.run(Main.java:710) at org.eclipse.core.launcher.Main.main(Main.java:694)
org.eclipse.ltk.core.refactoring/src/org/eclipse/ltk/core/refactoring/TextChange.java
* @param group the text edit group to add
	 */
	public void addTextEditGroup(TextEditGroup group) {
		addTextEditChangeGroup(new TextEditChangeGroup(this, group));
	}
	
	/**
	 * Adds a {@link TextEditChangeGroup text edit change group}. Calling the methods 
	 * requires that a root edit has been set via the method {@link #setEdit(TextEdit)
	 * setEdit}. The edits managed by the given text edit change group must be part of 
	 * the change's root edit. 
	 * 
	 * @param group the text edit change group to add
	 */
	public void addTextEditChangeGroup(TextEditChangeGroup group) {
		Assert.isTrue(fEdit != null, "Can only add a description if a root edit exists"); 
		Assert.isTrue(group != null);
		fTextEditChangeGroups.add(group);
	}
	
	/**
	 * Returns the {@link TextEditChangeGroup text edit change groups} managed by this 
	 * text change.
	 * 
	 * @return the text edit change groups
	 */
	public TextEditChangeGroup[] getTextEditChangeGroups() {
		return (TextEditChangeGroup[])fTextEditChangeGroups.toArray(new TextEditChangeGroup[fTextEditChangeGroups.size()]);
	}