Bug 98394 [refactoring] NPE while adding generic wildcard to method parameter
Take the following code: interface I { public void test(Class arg); } public class C implements I { public void test(Class arg) {} } Select either method declaration, do Refactor -> Change Method Signature, change the type "Class" to "Class<?>", select Preview or OK. This results in the following exception: java.lang.reflect.InvocationTargetException at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:327) at org.eclipse.ltk.internal.ui.refactoring.RefactoringWizardDialog2.run(RefactoringWizardDialog2.java:293) at org.eclipse.ltk.ui.refactoring.RefactoringWizard.createChange(RefactoringWizard.java:573) at org.eclipse.ltk.ui.refactoring.RefactoringWizard.computeUserInputSuccessorPage(RefactoringWizard.java:416) at org.eclipse.ltk.ui.refactoring.UserInputWizardPage.computeSuccessorPage(UserInputWizardPage.java:74) at org.eclipse.ltk.ui.refactoring.UserInputWizardPage.getNextPage(UserInputWizardPage.java:114) at org.eclipse.ltk.internal.ui.refactoring.RefactoringWizardDialog2.previewPressed(RefactoringWizardDialog2.java:447) at org.eclipse.ltk.internal.ui.refactoring.RefactoringWizardDialog2.access$3(RefactoringWizardDialog2.java:445) at org.eclipse.ltk.internal.ui.refactoring.RefactoringWizardDialog2$1.widgetSelected(RefactoringWizardDialog2.java:584) at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:89) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:844) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:2929) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2562) at org.eclipse.jface.window.Window.runEventLoop(Window.java:809) at org.eclipse.jface.window.Window.open(Window.java:787) 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.internal.ui.refactoring.UserInterfaceStarter.activate(UserInterfaceStarter.java:56) at org.eclipse.jdt.internal.corext.refactoring.RefactoringExecutionStarter$1.activate(RefactoringExecutionStarter.java:175) at org.eclipse.jdt.internal.corext.refactoring.RefactoringExecutionStarter.startChangeSignatureRefactoring(RefactoringExecutionStarter.java:180) at org.eclipse.jdt.ui.actions.ModifyParametersAction.run(ModifyParametersAction.java:132) at org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun(SelectionDispatchAction.java:226) at org.eclipse.jdt.ui.actions.SelectionDispatchAction.run(SelectionDispatchAction.java:198) at org.eclipse.jface.action.Action.runWithEvent(Action.java:996) at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:538) at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:488) at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:400) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:844) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:2929) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2562) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:1694) at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:1658) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:366) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:143) at org.eclipse.ui.internal.ide.IDEApplication.run(IDEApplication.java:103) at org.eclipse.core.internal.runtime.PlatformActivator$1.run(PlatformActivator.java:226) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:375) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:162) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.eclipse.core.launcher.Main.invokeFramework(Main.java:334) at org.eclipse.core.launcher.Main.basicRun(Main.java:278) at org.eclipse.core.launcher.Main.run(Main.java:973) at org.eclipse.core.launcher.Main.main(Main.java:948) Caused by: java.lang.NullPointerException at org.eclipse.jdt.internal.corext.refactoring.structure.ChangeSignatureRefactoring.collectTypeVariables(ChangeSignatureRefactoring.java:514) at org.eclipse.jdt.internal.corext.refactoring.structure.ChangeSignatureRefactoring.collectTypeVariables(ChangeSignatureRefactoring.java:530) at org.eclipse.jdt.internal.corext.refactoring.structure.ChangeSignatureRefactoring.collectTypeVariables(ChangeSignatureRefactoring.java:526) at org.eclipse.jdt.internal.corext.refactoring.structure.ChangeSignatureRefactoring.checkTypeVariables(ChangeSignatureRefactoring.java:502) at org.eclipse.jdt.internal.corext.refactoring.structure.ChangeSignatureRefactoring.checkFinalConditions(ChangeSignatureRefactoring.java:743) at org.eclipse.ltk.core.refactoring.CheckConditionsOperation.run(CheckConditionsOperation.java:84) at org.eclipse.ltk.core.refactoring.CreateChangeOperation.run(CreateChangeOperation.java:114) at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1719) at org.eclipse.ltk.internal.ui.refactoring.WorkbenchRunnableAdapter.run(WorkbenchRunnableAdapter.java:86) at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:113) Tested with 3.1RC1. The same happens with an abstract superclass instead of an interface. It does not happen when there is no subclass / implementing class.
org.eclipse.jdt.ui.tests.refactoring/resources/ChangeSignature/canModify/A_testGenerics02_out.java
package p;
import java.util.HashMap;
import java.util.List;
class A<E> {
	<T> void m(E e, T t, List<HashMap> maps) {}
}
class Sub<Q> extends A<Q> {
	void m(Q q, Integer i, List<HashMap> maps) {}
}