48706 – NPE in move refactoring

Bug 48706 - NPE in move refactoring

Summary: NPE in move refactoring

Status:	VERIFIED FIXED

Alias:	None

Product:	JDT
Classification:	Eclipse Project
Component:	Core (show other bugs)
Version:	3.0
Hardware:	All All

Importance:	P3 normal (vote)
Target Milestone:	3.0 M6
Assignee:	Jerome Lanneluc
QA Contact:

URL:
Whiteboard:
Keywords:

Depends on:
Blocks:

Reported:	2003-12-14 10:39 EST by Sebastian Davids
Modified:	2003-12-18 12:11 EST (History)
CC List:	2 users (show)

See Also:

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Description Sebastian Davids

2003-12-14 10:39:54 EST

Version: 3.0.0
Build id: 200311251047

This was my setup:

Project A ... several references to class "import x.y.z.ClassName"; Project B on
classpath.

Project B ... existing package "x.y.z.test" containing class "ClassNameTest",
the parent package "x.y.z" was empty.

I now imported ClassName into the default package (mistake on my side here).

I now invoked "Refactor/Move..." on that CU and selected "x.y.z" ... OK.

After a few seconds I changed my mind and pressed "Abort".

I'm not sure if the stuff below was appended to the log before I pressed Abort
or after.

Log entries:

!ENTRY org.eclipse.jdt.ui 4 10001 Dez 14, 2003 16:28:36.840
!MESSAGE Internal Error
!STACK 0
java.lang.NullPointerException
	at
org.eclipse.jdt.internal.core.JavaModelOperation.run(JavaModelOperation.java:715)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1555)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1574)
	at org.eclipse.jdt.internal.core.JavaElement.runOperation(JavaElement.java:528)
	at org.eclipse.jdt.internal.core.JavaModel.runOperation(JavaModel.java:315)
	at org.eclipse.jdt.internal.core.JavaModel.move(JavaModel.java:276)
	at org.eclipse.jdt.internal.core.CompilationUnit.move(CompilationUnit.java:950)
	at
org.eclipse.jdt.internal.corext.refactoring.changes.MoveCompilationUnitChange.doPeform(MoveCompilationUnitChange.java:72)
	at
org.eclipse.jdt.internal.corext.refactoring.changes.CompilationUnitReorgChange.perform(CompilationUnitReorgChange.java:60)
	at
org.eclipse.jdt.internal.corext.refactoring.CompositeChange.createUndoList(CompositeChange.java:122)
	at
org.eclipse.jdt.internal.corext.refactoring.CompositeChange.perform(CompositeChange.java:149)
	at
org.eclipse.jdt.internal.ui.refactoring.PerformChangeOperation$1.run(PerformChangeOperation.java:173)
	at
org.eclipse.jdt.internal.core.BatchOperation.executeOperation(BatchOperation.java:34)
	at
org.eclipse.jdt.internal.core.JavaModelOperation.execute(JavaModelOperation.java:367)
	at
org.eclipse.jdt.internal.core.JavaModelOperation.run(JavaModelOperation.java:706)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1555)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1574)
	at org.eclipse.jdt.core.JavaCore.run(JavaCore.java:2975)
	at
org.eclipse.jdt.internal.ui.refactoring.PerformChangeOperation.executeChange(PerformChangeOperation.java:183)
	at
org.eclipse.jdt.internal.ui.refactoring.PerformChangeOperation.run(PerformChangeOperation.java:145)
	at
org.eclipse.jface.operation.ModalContext.runInCurrentThread(ModalContext.java:302)
	at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:252)
	at
org.eclipse.jdt.internal.ui.refactoring.RefactoringWizardDialog2.run(RefactoringWizardDialog2.java:271)
	at
org.eclipse.jdt.internal.ui.refactoring.PerformRefactoringUtil.performRefactoring(PerformRefactoringUtil.java:53)
	at
org.eclipse.jdt.internal.ui.refactoring.RefactoringWizard.performFinish(RefactoringWizard.java:409)
	at
org.eclipse.jdt.internal.ui.refactoring.UserInputWizardPage.performFinish(UserInputWizardPage.java:119)
	at
org.eclipse.jdt.internal.ui.refactoring.reorg.ReorgMoveWizard$MoveInputPage.performFinish(ReorgMoveWizard.java:91)
	at
org.eclipse.jdt.internal.ui.refactoring.RefactoringWizard.performFinish(RefactoringWizard.java:472)
	at
org.eclipse.jdt.internal.ui.refactoring.RefactoringWizardDialog2.okPressed(RefactoringWizardDialog2.java:395)
	at org.eclipse.jface.dialogs.Dialog.buttonPressed(Dialog.java:263)
	at org.eclipse.jface.dialogs.Dialog$1.widgetSelected(Dialog.java:430)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:89)
	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:2296)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:1977)
	at org.eclipse.jface.window.Window.runEventLoop(Window.java:586)
	at org.eclipse.jface.window.Window.open(Window.java:566)
	at
org.eclipse.jdt.internal.ui.refactoring.actions.RefactoringStarter.activate(RefactoringStarter.java:56)
	at
org.eclipse.jdt.internal.ui.refactoring.reorg.ReorgMoveAction.startRefactoring(ReorgMoveAction.java:120)
	at
org.eclipse.jdt.internal.ui.refactoring.reorg.ReorgMoveAction.run(ReorgMoveAction.java:106)
	at
org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun(SelectionDispatchAction.java:194)
	at
org.eclipse.jdt.ui.actions.SelectionDispatchAction.run(SelectionDispatchAction.java:172)
	at org.eclipse.jdt.ui.actions.MoveAction.run(MoveAction.java:123)
	at
org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun(SelectionDispatchAction.java:194)
	at
org.eclipse.jdt.ui.actions.SelectionDispatchAction.run(SelectionDispatchAction.java:172)
	at org.eclipse.jface.action.Action.runWithEvent(Action.java:842)
	at
org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:542)
	at
org.eclipse.jface.action.ActionContributionItem.access$4(ActionContributionItem.java:494)
	at
org.eclipse.jface.action.ActionContributionItem$6.handleEvent(ActionContributionItem.java:466)
	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:2296)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:1977)
	at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:1405)
	at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:1381)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:237)
	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.boot.InternalBootLoader.run(InternalBootLoader.java:852)
	at org.eclipse.core.boot.BootLoader.run(BootLoader.java:462)
	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:299)
	at org.eclipse.core.launcher.Main.run(Main.java:767)
	at org.eclipse.core.launcher.Main.main(Main.java:601)
!ENTRY org.eclipse.jdt.core 4 2 Dez 14, 2003 16:28:38.412
!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.jdt.core".
!STACK 0
java.lang.NullPointerException
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.hasFineGrainChanges(TypeHierarchy.java:725)
	at org.eclipse.jdt.internal.core.DeltaProcessor$3.run(DeltaProcessor.java:1408)
	at
org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1127)
	at org.eclipse.core.runtime.Platform.run(Platform.java:464)
	at
org.eclipse.jdt.internal.core.DeltaProcessor.notifyTypeHierarchies(DeltaProcessor.java:1402)
	at
org.eclipse.jdt.internal.core.DeltaProcessor.resourceChanged(DeltaProcessor.java:1820)
	at
org.eclipse.jdt.internal.core.DeltaProcessingState.resourceChanged(DeltaProcessingState.java:226)
	at
org.eclipse.core.internal.events.NotificationManager$2.run(NotificationManager.java:251)
	at
org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1127)
	at org.eclipse.core.runtime.Platform.run(Platform.java:464)
	at
org.eclipse.core.internal.events.NotificationManager.notify(NotificationManager.java:244)
	at
org.eclipse.core.internal.events.NotificationManager.broadcastChanges(NotificationManager.java:138)
	at
org.eclipse.core.internal.resources.Workspace.broadcastChanges(Workspace.java:146)
	at org.eclipse.core.internal.resources.Workspace.endOperation(Workspace.java:847)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1564)
	at
org.eclipse.core.internal.events.NotificationManager$NotifyJob.run(NotificationManager.java:37)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:62)
!ENTRY org.eclipse.jdt.core 4 4 Dez 14, 2003 16:28:38.432
!MESSAGE Exception occurred in listener of Java element change notification
!STACK 0
java.lang.NullPointerException
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.hasFineGrainChanges(TypeHierarchy.java:725)
	at org.eclipse.jdt.internal.core.DeltaProcessor$3.run(DeltaProcessor.java:1408)
	at
org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1127)
	at org.eclipse.core.runtime.Platform.run(Platform.java:464)
	at
org.eclipse.jdt.internal.core.DeltaProcessor.notifyTypeHierarchies(DeltaProcessor.java:1402)
	at
org.eclipse.jdt.internal.core.DeltaProcessor.resourceChanged(DeltaProcessor.java:1820)
	at
org.eclipse.jdt.internal.core.DeltaProcessingState.resourceChanged(DeltaProcessingState.java:226)
	at
org.eclipse.core.internal.events.NotificationManager$2.run(NotificationManager.java:251)
	at
org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1127)
	at org.eclipse.core.runtime.Platform.run(Platform.java:464)
	at
org.eclipse.core.internal.events.NotificationManager.notify(NotificationManager.java:244)
	at
org.eclipse.core.internal.events.NotificationManager.broadcastChanges(NotificationManager.java:138)
	at
org.eclipse.core.internal.resources.Workspace.broadcastChanges(Workspace.java:146)
	at org.eclipse.core.internal.resources.Workspace.endOperation(Workspace.java:847)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1564)
	at
org.eclipse.core.internal.events.NotificationManager$NotifyJob.run(NotificationManager.java:37)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:62)
!ENTRY org.eclipse.jdt.core 4 2 Dez 14, 2003 16:28:38.503
!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.jdt.core".
!STACK 0
java.lang.NullPointerException
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByOpenable(TypeHierarchy.java:968)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffected(TypeHierarchy.java:825)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByChildren(TypeHierarchy.java:838)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByPackageFragment(TypeHierarchy.java:907)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffected(TypeHierarchy.java:822)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByChildren(TypeHierarchy.java:838)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByPackageFragmentRoot(TypeHierarchy.java:957)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffected(TypeHierarchy.java:820)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByChildren(TypeHierarchy.java:838)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByJavaProject(TypeHierarchy.java:889)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffected(TypeHierarchy.java:818)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByChildren(TypeHierarchy.java:838)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByJavaModel(TypeHierarchy.java:854)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffected(TypeHierarchy.java:816)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.elementChanged(TypeHierarchy.java:347)
	at org.eclipse.jdt.internal.core.DeltaProcessor$2.run(DeltaProcessor.java:1387)
	at
org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1127)
	at org.eclipse.core.runtime.Platform.run(Platform.java:464)
	at
org.eclipse.jdt.internal.core.DeltaProcessor.notifyListeners(DeltaProcessor.java:1382)
	at
org.eclipse.jdt.internal.core.DeltaProcessor.firePostChangeDelta(DeltaProcessor.java:1226)
	at org.eclipse.jdt.internal.core.DeltaProcessor.fire(DeltaProcessor.java:1205)
	at
org.eclipse.jdt.internal.core.DeltaProcessor.resourceChanged(DeltaProcessor.java:1821)
	at
org.eclipse.jdt.internal.core.DeltaProcessingState.resourceChanged(DeltaProcessingState.java:226)
	at
org.eclipse.core.internal.events.NotificationManager$2.run(NotificationManager.java:251)
	at
org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1127)
	at org.eclipse.core.runtime.Platform.run(Platform.java:464)
	at
org.eclipse.core.internal.events.NotificationManager.notify(NotificationManager.java:244)
	at
org.eclipse.core.internal.events.NotificationManager.broadcastChanges(NotificationManager.java:138)
	at
org.eclipse.core.internal.resources.Workspace.broadcastChanges(Workspace.java:146)
	at org.eclipse.core.internal.resources.Workspace.endOperation(Workspace.java:847)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1564)
	at
org.eclipse.core.internal.events.NotificationManager$NotifyJob.run(NotificationManager.java:37)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:62)
!ENTRY org.eclipse.jdt.core 4 4 Dez 14, 2003 16:28:38.523
!MESSAGE Exception occurred in listener of Java element change notification
!STACK 0
java.lang.NullPointerException
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByOpenable(TypeHierarchy.java:968)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffected(TypeHierarchy.java:825)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByChildren(TypeHierarchy.java:838)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByPackageFragment(TypeHierarchy.java:907)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffected(TypeHierarchy.java:822)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByChildren(TypeHierarchy.java:838)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByPackageFragmentRoot(TypeHierarchy.java:957)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffected(TypeHierarchy.java:820)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByChildren(TypeHierarchy.java:838)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByJavaProject(TypeHierarchy.java:889)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffected(TypeHierarchy.java:818)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByChildren(TypeHierarchy.java:838)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffectedByJavaModel(TypeHierarchy.java:854)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.isAffected(TypeHierarchy.java:816)
	at
org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.elementChanged(TypeHierarchy.java:347)
	at org.eclipse.jdt.internal.core.DeltaProcessor$2.run(DeltaProcessor.java:1387)
	at
org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1127)
	at org.eclipse.core.runtime.Platform.run(Platform.java:464)
	at
org.eclipse.jdt.internal.core.DeltaProcessor.notifyListeners(DeltaProcessor.java:1382)
	at
org.eclipse.jdt.internal.core.DeltaProcessor.firePostChangeDelta(DeltaProcessor.java:1226)
	at org.eclipse.jdt.internal.core.DeltaProcessor.fire(DeltaProcessor.java:1205)
	at
org.eclipse.jdt.internal.core.DeltaProcessor.resourceChanged(DeltaProcessor.java:1821)
	at
org.eclipse.jdt.internal.core.DeltaProcessingState.resourceChanged(DeltaProcessingState.java:226)
	at
org.eclipse.core.internal.events.NotificationManager$2.run(NotificationManager.java:251)
	at
org.eclipse.core.internal.runtime.InternalPlatform.run(InternalPlatform.java:1127)
	at org.eclipse.core.runtime.Platform.run(Platform.java:464)
	at
org.eclipse.core.internal.events.NotificationManager.notify(NotificationManager.java:244)
	at
org.eclipse.core.internal.events.NotificationManager.broadcastChanges(NotificationManager.java:138)
	at
org.eclipse.core.internal.resources.Workspace.broadcastChanges(Workspace.java:146)
	at org.eclipse.core.internal.resources.Workspace.endOperation(Workspace.java:847)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1564)
	at
org.eclipse.core.internal.events.NotificationManager$NotifyJob.run(NotificationManager.java:37)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:62)

Comment 1 Dirk Baeumer

2003-12-14 12:39:42 EST

Sebastian,

refactor/move can be aborted/canceled (the button in disabed). Can you please 
explain how you canceled the operation.

Comment 2 Sebastian Davids

2003-12-14 21:40:03 EST

I clicked on Abort.

Comment 3 Sebastian Davids

2003-12-14 22:04:07 EST

Looking at the source code I think it is a threading problem:

protected boolean isAffectedByOpenable(IJavaElementDelta delta, IJavaElement
element) {
	if (element instanceof CompilationUnit) {
		CompilationUnit cu = (CompilationUnit)element;
		ChangeCollector collector = this.changeCollector == null ? new
ChangeCollector(this) : this.changeCollector;
		try {
			collector.addChange(cu, delta); //<------exception thrown here

@@@@

public boolean hasFineGrainChanges() {
	return this.changeCollector != null && this.changeCollector.needsRefresh();
}

@@@@

Seems as if somehow another thread has set changeCollector to null after the
null-check has been made.

In the middle of refresh(IProgressMonitor) changeCollector is set to null.

Probably both methods above have to be synchronized.

Comment 4 Dirk Baeumer

2003-12-15 13:50:59 EST

The only dialog that has an abort button is the one shown when an unexpected 
error was thrown by the refactoring. Can you remember the sort of error that 
was presented. Best would be if you can provide the corresponding stack trace 
from the log.

Regarding your observations: I am not sure that the stack traces are connected 
to the problem you had. So I would first like to reproduce the problem.

Comment 5 Sebastian Davids

2003-12-15 17:53:49 EST

I've looked through the log file ... the stack traces above are the only ones
logged at that particular time.

Unfortunately I don't remember the wording of the dialog.

I tried to reproduce the error w/ the same workspace and repeatedly
moving/importing the file -- I couldn't.

I still think that it is a concurrency problem that's why I cannot reproduce it
"easily" -- problem is I do not know what happened in the background at that time :/

Comment 6 Dirk Baeumer

2003-12-16 17:13:00 EST

All the exceptions happen in JDT/COre code. Philippe can you please comment on 
this and the comment #3.

Comment 7 Philipe Mulet

2003-12-16 18:29:12 EST

Jerome - pls investigate (and adopt if our fault)

Comment 8 Jerome Lanneluc

2003-12-17 06:11:09 EST

First NPE in JavaModelOperation at line 715 can only happen 
if 'deltaProcessor.javaModelDeltas' is null. Howver looking at the write 
accesses to this field, it appears always initialized to a non-null value. It 
sounds like a VM/JIT problem.

Sebastian which VM are you using to run Eclipse?

Comment 9 Sebastian Davids

2003-12-17 06:43:02 EST

Win XP

Sun JRE 1.4.2_02-b03
Java HotSpot 1.4.2_02-b03, mixed mode

single processor

Comment 10 Jerome Lanneluc

2003-12-17 12:38:17 EST

Added protection when accessing 'changeCollector' field (using a local variable 
before checking if it is null)

Comment 11 Sebastian Davids

2003-12-17 14:41:23 EST

fix looks good to me

Comment 12 Jerome Lanneluc

2003-12-18 12:11:52 EST

Verified that the code for the fix is included in I200312180955