Program: 69356
Project: 69356
Buggy source:
private void placeComponent(){
  mainComposite.setLayoutData(new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL));
  mainComposite.setLayout(new GridLayout(3,true));
  Group sGroup=new Group(mainComposite,SWT.NONE);
  sGroup.setLayout(new GridLayout());
  sGroup.setLayoutData(new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL));
  sGroup.setText(Messages.getString("String_Node_Str"));
  createTree(sGroup);
  Composite rComp=new Composite(mainComposite,SWT.NONE);
  GridData gridData=new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL);
  gridData.horizontalSpan=2;
  rComp.setLayout(new GridLayout());
  rComp.setLayoutData(gridData);
  Group preGroup=new Group(rComp,SWT.NONE);
  preGroup.setLayout(new GridLayout());
  preGroup.setLayoutData(new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL));
  preGroup.setText(Messages.getString("String_Node_Str"));
  gridData=new GridData(GridData.FILL_VERTICAL | GridData.HORIZONTAL_ALIGN_FILL);
  preGroup.setLayoutData(gridData);
  paintCanvas=new Canvas(preGroup,SWT.BORDER);
  paintCanvas.setLayoutData(new GridData(GridData.FILL_BOTH));
  paintCanvas.setBackground(Display.getDefault().getSystemColor(SWT.COLOR_WHITE));
  preview=new ChartPreview();
  paintCanvas.addPaintListener(preview);
  paintCanvas.addControlListener(preview);
  preview.setPreview(paintCanvas);
  Group desGroup=new Group(rComp,SWT.NONE);
  desGroup.setLayout(new GridLayout());
  gridData=new GridData(GridData.FILL_HORIZONTAL);
  gridData.heightHint=60;
  desGroup.setLayoutData(gridData);
  desGroup.setText(Messages.getString("String_Node_Str"));
  description=new Label(desGroup,SWT.WRAP);
  description.setLayoutData(new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL));
  description.setText(icp.getDefaultDescription());
}

Fixed version (ground truth):
private void placeComponent(){
  mainComposite.setLayoutData(new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL));
  mainComposite.setLayout(new GridLayout(3,true));
  Group sGroup=new Group(mainComposite,SWT.NONE);
  sGroup.setLayout(new GridLayout());
  sGroup.setLayoutData(new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL));
  sGroup.setText(Messages.getString("String_Node_Str"));
  createTree(sGroup);
  Composite rComp=new Composite(mainComposite,SWT.NONE);
  GridData gridData=new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL);
  gridData.horizontalSpan=2;
  rComp.setLayout(new GridLayout());
  rComp.setLayoutData(gridData);
  Group preGroup=new Group(rComp,SWT.NONE);
  preGroup.setLayout(new GridLayout());
  preGroup.setLayoutData(new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL));
  preGroup.setText(Messages.getString("String_Node_Str"));
  gridData=new GridData(GridData.FILL_VERTICAL | GridData.HORIZONTAL_ALIGN_FILL);
  preGroup.setLayoutData(gridData);
  paintCanvas=new Canvas(preGroup,SWT.BORDER);
  paintCanvas.setLayoutData(new GridData(GridData.FILL_BOTH));
  paintCanvas.setBackground(Display.getDefault().getSystemColor(SWT.COLOR_WHITE));
  preview=new ChartPreview();
  paintCanvas.addPaintListener(preview);
  paintCanvas.addControlListener(preview);
  preview.setPreview(paintCanvas);
  Group desGroup=new Group(rComp,SWT.NONE);
  desGroup.setLayout(new GridLayout());
  gridData=new GridData(GridData.FILL_HORIZONTAL);
  gridData.heightHint=60;
  desGroup.setLayoutData(gridData);
  desGroup.setText(Messages.getString("String_Node_Str"));
  description=new Text(desGroup,SWT.WRAP | SWT.READ_ONLY | SWT.V_SCROLL);
  description.setLayoutData(new GridData(GridData.FILL_VERTICAL | GridData.FILL_HORIZONTAL));
  description.setText(icp.getDefaultDescription());
}