Program: 95933
Project: 95933
Buggy source:
/** 
 * Creates the EventHandler part of the editor
 * @param parent Composite
 */
private void createEventHandlerPart(Composite parent){
  Composite headLineComposite=new Composite(parent,SWT.NONE);
  GridLayout layout=new GridLayout(1,true);
  layout.marginWidth=0;
  layout.marginHeight=0;
  layout.marginBottom=0;
  layout.marginTop=0;
  headLineComposite.setLayout(layout);
  Label headLine=new Label(headLineComposite,SWT.NONE);
  headLine.setText(Messages.TestCaseEditorEHAreaHeadline);
  ControlDecorator.decorateInfo(headLine,"String_Node_Str",false);
  GridData ehTvGridData=new GridData();
  ehTvGridData.grabExcessHorizontalSpace=true;
  ehTvGridData.grabExcessVerticalSpace=true;
  ehTvGridData.horizontalAlignment=SWT.FILL;
  ehTvGridData.verticalAlignment=SWT.FILL;
  ehTvGridData.verticalSpan=100;
  GridLayout ehTvLayout=new GridLayout(1,true);
  ehTvLayout.marginWidth=0;
  ehTvLayout.marginHeight=0;
  ehTvLayout.marginBottom=0;
  ehTvLayout.marginTop=0;
  m_eventHandlerTreeViewer=new TreeViewer(headLineComposite);
  m_eventHandlerTreeViewer.getTree().setLayout(ehTvLayout);
  m_eventHandlerTreeViewer.getTree().setLayoutData(ehTvGridData);
  ColumnViewerToolTipSupport.enableFor(m_eventHandlerTreeViewer);
  DecoratingCellLabelProvider lp=new DecoratingCellLabelProvider(new TooltipLabelProvider(),Plugin.getDefault().getWorkbench().getDecoratorManager().getLabelDecorator());
  m_eventHandlerTreeViewer.setLabelProvider(lp);
  m_eventHandlerTreeViewer.setComparer(new UIIdentitiyElementComparer());
  m_eventHandlerTreeViewer.setUseHashlookup(true);
  m_eventHandlerTreeViewer.getTree().addListener(SWT.MouseDown,new MouseDownListener());
  firePropertyChange(IWorkbenchPartConstants.PROP_INPUT);
}

Fixed version (ground truth):
/** 
 * Creates the EventHandler part of the editor
 * @param parent Composite
 */
private void createEventHandlerPart(Composite parent){
  Composite headLineComposite=new Composite(parent,SWT.NONE);
  GridLayout layout=new GridLayout(1,true);
  layout.marginWidth=0;
  layout.marginHeight=0;
  layout.marginBottom=0;
  layout.marginTop=0;
  headLineComposite.setLayout(layout);
  Label headLine=new Label(headLineComposite,SWT.NONE);
  headLine.setText(Messages.TestCaseEditorEHAreaHeadline);
  ControlDecorator.decorateInfo(headLine,"String_Node_Str",false);
  GridData ehTvGridData=new GridData();
  ehTvGridData.grabExcessHorizontalSpace=true;
  ehTvGridData.grabExcessVerticalSpace=true;
  ehTvGridData.horizontalAlignment=SWT.FILL;
  ehTvGridData.verticalAlignment=SWT.FILL;
  ehTvGridData.verticalSpan=100;
  GridLayout ehTvLayout=new GridLayout(1,true);
  ehTvLayout.marginWidth=0;
  ehTvLayout.marginHeight=0;
  ehTvLayout.marginBottom=0;
  ehTvLayout.marginTop=0;
  m_eventHandlerTreeViewer=new TreeViewer(headLineComposite);
  m_eventHandlerTreeViewer.getTree().setLayout(ehTvLayout);
  m_eventHandlerTreeViewer.getTree().setLayoutData(ehTvGridData);
  ColumnViewerToolTipSupport.enableFor(m_eventHandlerTreeViewer);
  DecoratingCellLabelProvider lp=new DecoratingCellLabelProvider(new TooltipLabelProvider(),Plugin.getDefault().getWorkbench().getDecoratorManager().getLabelDecorator());
  m_eventHandlerTreeViewer.setLabelProvider(lp);
  m_eventHandlerTreeViewer.setComparer(new UIIdentitiyElementComparer());
  m_eventHandlerTreeViewer.setUseHashlookup(true);
  firePropertyChange(IWorkbenchPartConstants.PROP_INPUT);
}