Program: 146115
Project: 146115
Buggy source:
@Override protected Control createDialogArea(Composite parent){
  Group comp=new Group(parent,SWT.NONE);
  comp.setLayoutData(new GridData(SWT.FILL,SWT.FILL,true,true,1,1));
  ((GridLayout)parent.getLayout()).marginTop=5;
  ((GridLayout)parent.getLayout()).marginLeft=5;
  ((GridLayout)parent.getLayout()).marginRight=5;
  ((GridLayout)parent.getLayout()).marginBottom=5;
  parent.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_WHITE));
  comp.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_WHITE));
  comp.setLayout(new GridLayout(1,false));
  comp.setText("String_Node_Str" + transformer.getName() + "String_Node_Str");
  Set<String> inputVariables=new HashSet<String>();
  for (  WSTransformerProcessStep step : transformer.getProcessSteps()) {
    for (    WSTransformerVariablesMapping mapping : step.getInputMappings()) {
      inputVariables.add(mapping.getPipelineVariable() == null ? TransformerMainPage.DEFAULT_VAR : mapping.getPipelineVariable());
    }
  }
  ComplexTableViewerColumn[] columns=new ComplexTableViewerColumn[]{new ComplexTableViewerColumn("String_Node_Str",true,"String_Node_Str","String_Node_Str","String_Node_Str",true,inputVariables.toArray(new String[inputVariables.size()]),0),new ComplexTableViewerColumn("String_Node_Str",false,"String_Node_Str","String_Node_Str","String_Node_Str",true,new String[]{"String_Node_Str","String_Node_Str"},0),new ComplexTableViewerColumn("String_Node_Str",true,"String_Node_Str","String_Node_Str","String_Node_Str",false,null,10)};
  objectViewer=new ComplexTableViewer(Arrays.asList(columns),toolkit,comp);
  objectViewer.create();
  Table table=objectViewer.getViewer().getTable();
  table.getColumns()[2].setWidth(500);
  table.setHeaderVisible(true);
  table.setLinesVisible(true);
  if (page.getCacheList() != null) {
    objectViewer.getViewer().setInput(page.getCacheList());
  }
 else {
    List<Line> list=new ArrayList<Line>();
    objectViewer.getViewer().setInput(list);
  }
  return comp;
}

Fixed version (ground truth):
@Override protected Control createDialogArea(Composite parent){
  Group comp=new Group(parent,SWT.NONE);
  comp.setLayoutData(new GridData(SWT.FILL,SWT.FILL,true,true,1,1));
  ((GridLayout)parent.getLayout()).marginTop=5;
  ((GridLayout)parent.getLayout()).marginLeft=5;
  ((GridLayout)parent.getLayout()).marginRight=5;
  ((GridLayout)parent.getLayout()).marginBottom=5;
  parent.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_WHITE));
  comp.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_WHITE));
  comp.setLayout(new GridLayout(1,false));
  comp.setText("String_Node_Str" + transformer.getName() + "String_Node_Str");
  Set<String> inputVariables=new HashSet<String>();
  for (  WSTransformerProcessStep step : transformer.getProcessSteps()) {
    for (    WSTransformerVariablesMapping mapping : step.getInputMappings()) {
      inputVariables.add(mapping.getPipelineVariable() == null ? TransformerMainPage.DEFAULT_VAR : mapping.getPipelineVariable());
    }
  }
  ComplexTableViewerColumn[] columns=new ComplexTableViewerColumn[]{new ComplexTableViewerColumn("String_Node_Str",true,"String_Node_Str","String_Node_Str","String_Node_Str",true,inputVariables.toArray(new String[inputVariables.size()]),0),new ComplexTableViewerColumn("String_Node_Str",false,"String_Node_Str","String_Node_Str","String_Node_Str",true,new String[]{"String_Node_Str","String_Node_Str","String_Node_Str"},0),new ComplexTableViewerColumn("String_Node_Str",true,"String_Node_Str","String_Node_Str","String_Node_Str",false,null,10)};
  objectViewer=new ComplexTableViewer(Arrays.asList(columns),toolkit,comp);
  objectViewer.create();
  Table table=objectViewer.getViewer().getTable();
  table.getColumns()[2].setWidth(500);
  table.setHeaderVisible(true);
  table.setLinesVisible(true);
  if (page.getCacheList() != null) {
    objectViewer.getViewer().setInput(page.getCacheList());
  }
 else {
    List<Line> list=new ArrayList<Line>();
    objectViewer.getViewer().setInput(list);
  }
  return comp;
}