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Bug 312704

Summary:

NPE during Servlet creation operation

Product:

[WebTools] WTP Java EE Tools

Reporter:

Chuck Bridgham <cbridgha>

Component:

jst.j2ee

Assignee:

Chuck Bridgham <cbridgha>

Status:

RESOLVED FIXED

QA Contact:

Chuck Bridgham <cbridgha>

Severity:

normal

Priority:

CC:

ccc, david_williams, jsholl

Version:

3.2

Flags:

david_williams: pmc_approved+
jsholl: pmc_approved? (raghunathan.srinivasan)
jsholl: pmc_approved? (naci.dai)
jsholl: pmc_approved? (deboer)
jsholl: pmc_approved? (neil.hauge)
jsholl: pmc_approved? (kaloyan)
ccc: review+

Target Milestone:

3.2 RC1

Hardware:

OS:

Windows 7

Whiteboard:

PMC_approved

Attachments:

Description	Flags
patch	none

Description Chuck Bridgham

2010-05-12 16:00:50 EDT

This exception caused by a race condition can occur during Servlet creation



!ENTRY org.eclipse.wst.common.frameworks 4 0 2010-05-03 16:07:30.859
!MESSAGE Extended Operation failure: org.eclipse.jst.j2ee.internal.web.operations.AddServletOperation
!STACK 0
java.lang.NullPointerException
	at org.eclipse.jst.j2ee.web.componentcore.util.WebArtifactEdit.modify(WebArtifactEdit.java:693)
	at com.ibm.etools.javaee.model.internal.Web25ModelProvider.modify(Web25ModelProvider.java:293)
	at org.eclipse.jst.j2ee.internal.common.operations.AddJavaEEArtifactOperation.execute(AddJavaEEArtifactOperation.java:53)
	at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl$1.run(DataModelPausibleOperationImpl.java:385)
	at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1975)
	at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl.runOperation(DataModelPausibleOperationImpl.java:410)
	at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl.runOperation(DataModelPausibleOperationImpl.java:360)
	at org.eclipse.wst.common.frameworks.internal.datamodel.DataModelPausibleOperationImpl.doExecute(DataModelPausibleOperationImpl.java:247)

Although related fixes have made this condition unlikely, a null check is needed

Comment 1 Chuck Bridgham

2010-05-12 16:54:16 EDT

Created attachment 168265 [details]
patch

Comment 2 Carl Anderson

2010-05-12 16:57:31 EDT

I approve of this change.

Comment 3 Jason Sholl

2010-05-12 18:46:01 EDT

    * Explain why you believe this is a stop-ship defect. Or, if it is a "hotbug" (requested by an adopter) please document it as such. 

A rare race condition can lead to NPEs and blow up the stack.

    * Is there a work-around? If so, why do you believe the work-around is insufficient? 

No

    * How has the fix been tested? Is there a test case attached to the bugzilla record? Has a JUnit Test been added? 

Testing with UI


    * Give a brief technical overview. Who has reviewed this fix? 

The race condition can be avoided with a simple null check.  Carl and Jason have reviewed this fix.

    * What is the risk associated with this fix? 

None.

Comment 4 David Williams

2010-05-12 22:40:17 EDT

I'm not sure its correct to say "The race condition can be avoided ..." by a null check, but I agree, null checks should always be done in finally blocks before dispose.

Comment 5 Carl Anderson

2010-05-13 00:06:42 EDT

Committed to HEAD for WTP 3.2 RC1