Some Eclipse Foundation services are deprecated, or will be soon. Please ensure you've read this important communication.

Bug 344605

Summary:

NPE in MergeService.merge

Product:

[Modeling] EMFCompare

Reporter:

Martin Domig <martin>

Component:

Core

Assignee:

EMF Compare <emf.compare-inbox>

Status:

CLOSED WORKSFORME

QA Contact:

Severity:

major

Priority:

CC:

laurent.goubet

Version:

unspecified

Target Milestone:

---

Hardware:

OS:

Windows XP

Whiteboard:

Attachments:

Description	Flags
ecore file causing the NPE	none

Description Martin Domig

2011-05-03 12:19:17 EDT

Build Identifier: 20110218-0911

After adding an EInt attribute to a model, the following code fails with a NullPointerException:

MatchModel match = MatchService.doContentMatch(newSection, section, null);
DiffModel diff = DiffService.doDiff(match, false);
MergeService.merge(diff.getOwnedElements(), true);


Stacktrace:

java.lang.NullPointerException
	at org.eclipse.emf.compare.util.EFactory.eStructuralFeature(EFactory.java:287)
	at org.eclipse.emf.compare.util.EFactory.eGet(EFactory.java:156)
	at org.eclipse.emf.compare.diff.internal.merge.impl.UpdateAttributeMerger.undoInTarget(UpdateAttributeMerger.java:58)
	at org.eclipse.emf.compare.diff.merge.service.MergeService.doMerge(MergeService.java:166)
	at org.eclipse.emf.compare.diff.merge.service.MergeService.merge(MergeService.java:130)
	at org.eclipse.emf.compare.diff.internal.merge.impl.DiffGroupMerger.undoInTarget(DiffGroupMerger.java:48)
	at org.eclipse.emf.compare.diff.merge.service.MergeService.doMerge(MergeService.java:166)
	at org.eclipse.emf.compare.diff.merge.service.MergeService.merge(MergeService.java:130)
	at org.eclipse.emf.compare.diff.internal.merge.impl.DiffGroupMerger.undoInTarget(DiffGroupMerger.java:48)
	at org.eclipse.emf.compare.diff.merge.service.MergeService.doMerge(MergeService.java:166)
	at org.eclipse.emf.compare.diff.merge.service.MergeService.merge(MergeService.java:130)
	at org.eclipse.emf.compare.diff.internal.merge.impl.DiffGroupMerger.undoInTarget(DiffGroupMerger.java:48)
	at org.eclipse.emf.compare.diff.merge.service.MergeService.doMerge(MergeService.java:166)
	at org.eclipse.emf.compare.diff.merge.service.MergeService.merge(MergeService.java:130)
	at org.eclipse.emf.compare.diff.internal.merge.impl.DiffGroupMerger.undoInTarget(DiffGroupMerger.java:48)
	at org.eclipse.emf.compare.diff.merge.service.MergeService.doMerge(MergeService.java:166)
	at org.eclipse.emf.compare.diff.merge.service.MergeService.merge(MergeService.java:130)


Problem seems to be in UpdateAttributeMerger.undoInTarget:

final UpdateAttribute theDiff = (UpdateAttribute)this.diff;
...
final EObject origin = theDiff.getLeftElement();

origin is null here for some reason, and later dereferenced in EFactory.eGet().

Reproducible: Always

Steps to Reproduce:
Use the attached ecore model.
Create two identical section objects with a few groups and parameters.
Change one parameter in one of them.
Do the merge as described.

Comment 1 Martin Domig

2011-05-03 12:23:45 EDT

Created attachment 194607 [details]
ecore file causing the NPE

ecore file describing the model. After adding the ParameterGroup/order attribute, things went south.

Comment 2 Martin Domig

2011-05-03 12:25:28 EDT

Eclipse Version: Helios Service Release 2
EMF Compare SDK version: 1.1.2.v20110202-0936

Comment 3 Laurent Goubet

2011-05-04 05:03:05 EDT

Martin,

This cannot be reproduced from the GUI, or at least not with the example models I've created using the provided metamodel.

Do you still have this issue when you use "MatchService.doResourceSetMatch(newSection.eResource().getResourceSet(), section.eResource().getResourceSet())" instead of "doContentMatch" ?

Could you create a small unit test that would allow us to reproduce the failure?

Comment 4 Laurent Goubet

2011-06-15 10:17:20 EDT

Closing this bug as for now, will reopen if it can be reproduced.