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Bug 422034

Summary: [Workbench] ClassCastException: HandlerProcessingAddon casts an MHandlerContainer to an MContext without check
Product: [Eclipse Project] Platform Reporter: Thorsten Hake <thorsten.hake>
Component: UIAssignee: Paul Webster <pwebster>
Status: VERIFIED FIXED QA Contact: Paul Webster <pwebster>
Severity: normal    
Priority: P3 Keywords: helpwanted
Version: 4.3.1   
Target Milestone: 4.4 M4   
Hardware: PC   
OS: Windows 7   
Whiteboard:
Bug Depends on:    
Bug Blocks: 422971, 423852    

Description Thorsten Hake CLA 2013-11-19 04:22:18 EST 
The HandlerProcessingAddon casts an MHandlerContainer to an MContext without checking if the MHandlerContainer is of type MContext. 

As this is true for most of the classes implementing MHandlerContainer, it is not true for all. One example is MPartDescriptor. The HandlerProcessingAddon fails with an ClassCastException if one removes an MHandler from an MPartDescriptor.


For 4.3.1 the stacktrace is as follows:
java.lang.ClassCastException: org.eclipse.e4.ui.model.application.descriptor.basic.impl.PartDescriptorImpl cannot be cast to org.eclipse.e4.ui.model.application.ui.MContext
	at org.eclipse.e4.ui.internal.workbench.addons.HandlerProcessingAddon$1.handleEvent(HandlerProcessingAddon.java:88) ~[na:na]
	at org.eclipse.e4.ui.services.internal.events.UIEventHandler$1.run(UIEventHandler.java:41) ~[na:na]
	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35) ~[na:na]
	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135) ~[na:na]
	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4145) ~[na:na]
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3762) ~[na:na]
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1113) ~[na:na]
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) ~[na:na]
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:997) ~[na:na]
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:138) ~[na:na]
	at org.eclipse.e4.ui.internal.workbench.swt.E4Application.start(E4Application.java:162) ~[na:na]
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196) ~[na:na]
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110) ~[na:na]
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79) ~[na:na]
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:354) ~[na:na]
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:181) ~[na:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.7.0_07]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) ~[na:1.7.0_07]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.7.0_07]
	at java.lang.reflect.Method.invoke(Method.java:601) ~[na:1.7.0_07]
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:636) ~[org.eclipse.equinox.launcher_1.3.0.v20130327-1440.jar:na]
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:591) ~[org.eclipse.equinox.launcher_1.3.0.v20130327-1440.jar:na]
	at org.eclipse.equinox.launcher.Main.run(Main.java:1450) ~[org.eclipse.equinox.launcher_1.3.0.v20130327-1440.jar:na]
Comment 1 Thorsten Hake CLA 2013-11-28 03:36:34 EST 
Added Gerrit Patch for this bug: https://git.eclipse.org/r/#/c/19039/
Comment 2 Paul Webster CLA 2013-11-29 15:54:15 EST 
(In reply to Thorsten Hake from comment #1)
> Added Gerrit Patch for this bug: https://git.eclipse.org/r/#/c/19039/

I've added  https://git.eclipse.org/r/19151

We introduced some kind of weird loop that we had to fix in R4_3_maintenance.

PW
Comment 4 Thorsten Hake CLA 2013-12-02 04:41:35 EST 
I'm glad that I could help.

Is there any possibility to merge it into the R4_3_maintenance branch so that this minor fix is available for 4.3 SR2?
Comment 5 Paul Webster CLA 2013-12-11 13:17:00 EST 
In 4.4.0.I20131209-2000

PW