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Bug 438023

Summary:

[Tree] Expand/Collapse event has null item in some cases

Product:

[RT] RAP

Reporter:

Ivan Furnadjiev <ivan>

Component:

RWT

Assignee:

Project Inbox <rap-inbox>

Status:

RESOLVED FIXED

QA Contact:

Severity:

normal

Priority:

Version:

2.0

Target Milestone:

3.0 M1

Hardware:

OS:

Windows 7

Whiteboard:

sr231

Attachments:

Description	Flags
Workbench Demo patch to reproduce the issue	none

Description Ivan Furnadjiev

2014-06-24 07:11:42 EDT

Prerequisites:
1. UI request is running
2. User expand/collapse an item - expand/collapse notify operation is enqueued
3. Item is disposed by the server
4. Next UI request contains expand/collapse notify operation on already disposed item
5. Tree expand/collapse event is fired on the server with null item
As a result NPE is thrown if JFace TreeViewer is used:
java.lang.NullPointerException
	at org.eclipse.jface.viewers.AbstractTreeViewer.createChildren(AbstractTreeViewer.java:779)
	at org.eclipse.jface.viewers.TreeViewer.createChildren(TreeViewer.java:644)
	at org.eclipse.jface.viewers.AbstractTreeViewer.createChildren(AbstractTreeViewer.java:750)
	at org.eclipse.jface.viewers.AbstractTreeViewer.handleTreeExpand(AbstractTreeViewer.java:1447)
	at org.eclipse.jface.viewers.TreeViewer.handleTreeExpand(TreeViewer.java:952)
	at org.eclipse.jface.viewers.AbstractTreeViewer$4.treeExpanded(AbstractTreeViewer.java:1458)
	at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:160)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:86)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:699)
	at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:601)
	at org.eclipse.swt.widgets.Display.executeNextEvent(Display.java:1212)
	at org.eclipse.swt.widgets.Display.runPendingMessages(Display.java:1193)
	at org.eclipse.swt.widgets.Display.safeReadAndDispatch(Display.java:1176)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:1168)
	at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2733)
	at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2694)
	at org.eclipse.ui.internal.Workbench.access$5(Workbench.java:2530)
	at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:701)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:684)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:157)
	at org.eclipse.rap.demo.DemoWorkbench.createUI(DemoWorkbench.java:39)
	at org.eclipse.rap.rwt.internal.lifecycle.RWTLifeCycle.createUI(RWTLifeCycle.java:171)
	at org.eclipse.rap.rwt.internal.lifecycle.RWTLifeCycle$UIThreadController.run(RWTLifeCycle.java:283)
	at java.lang.Thread.run(Thread.java:744)
	at org.eclipse.rap.rwt.internal.lifecycle.UIThread.run(UIThread.java:104)

Comment 1 Ivan Furnadjiev

2014-06-24 07:17:55 EDT

Created attachment 244466 [details]
Workbench Demo patch to reproduce the issue

1. Apply the patch to Workbench Demo
2. Activate View II (next to the chart)
3. Click on "Refresh" view part action
4. Before the blocking overlay appear expand the root item
NPE is printed on the console.

Comment 2 Ivan Furnadjiev

2014-06-24 07:20:03 EDT

The cause: TreeOperationHandler fire expand/collapse event regardless the item. We should not fire the event if item is null (item is already disposed in the previous request).

Comment 3 Ivan Furnadjiev

2014-06-24 08:06:20 EDT

Pending change: https://git.eclipse.org/r/28913

Comment 4 Ivan Furnadjiev

2014-06-24 10:55:44 EDT

Fixed in master with change https://git.eclipse.org/r/28913.