Bug 63155 [Refactoring] no user feedback when error during implicit refactoring triggered by drag'n'drop
org.eclipse.ltk.core.refactoring/src/org/eclipse/ltk/core/refactoring/participants/ProcessorBasedRefactoring.java
result.merge(context.check(new SubProgressMonitor(pm, 1)));
		pm.done();
		return result;		
	}
	
	/**
	 * {@inheritDoc}
	 */
	public Change createChange(IProgressMonitor pm) throws CoreException {
		if (pm == null)
			pm= new NullProgressMonitor();
		pm.beginTask("", fParticipants.length + 2); 
		pm.setTaskName(RefactoringCoreMessages.getString("ProcessorBasedRefactoring.create_change")); 
		Change processorChange= getProcessor().createChange(new SubProgressMonitor(pm, 1));
		if (pm.isCanceled())
			throw new OperationCanceledException();
		
		List changes= new ArrayList();
		Map participantMap= new HashMap();
		for (int i= 0; i < fParticipants.length; i++) {
			RefactoringParticipant participant= fParticipants[i];
			try {
				Change change= participant.createChange(new SubProgressMonitor(pm, 1));
				if (change != null) {
					changes.add(change);
					participantMap.put(change, participant);
				}
			} catch (CoreException e) {
				ParticipantDescriptor descriptor= participant.getDescriptor();
				descriptor.disable();