Program: 75390
Project: 75390
Buggy source:
protected Control createControl(Composite parent){
  Composite editorComposite=new Composite(parent,getStyle());
  editorComposite.setLayout(new ExpressionCellLayout());
  expressionText=new Text(editorComposite,SWT.NONE);
  expressionText.addKeyListener(new KeyAdapter(){
    public void keyReleased(    KeyEvent e){
      keyReleaseOccured(e);
    }
  }
);
  expressionText.addSelectionListener(new SelectionAdapter(){
    public void widgetDefaultSelected(    SelectionEvent e){
    }
  }
);
  expressionText.addTraverseListener(new TraverseListener(){
    public void keyTraversed(    TraverseEvent e){
      if (e.detail == SWT.TRAVERSE_ESCAPE || e.detail == SWT.TRAVERSE_RETURN) {
        e.doit=false;
      }
    }
  }
);
  expressionText.addFocusListener(new FocusAdapter(){
    public void focusLost(    FocusEvent e){
      ExpressionValueCellEditor.this.focusLost();
    }
  }
);
  btnPopup=new Button(editorComposite,SWT.ARROW | SWT.DOWN);
  btnPopup.addSelectionListener(new SelectionListener(){
    public void widgetSelected(    SelectionEvent e){
      refreshList();
      Rectangle textBounds=expressionText.getBounds();
      Point pt=expressionText.toDisplay(textBounds.x,textBounds.y);
      Rectangle rect=new Rectangle(pt.x,pt.y,expressionText.getParent().getBounds().width,textBounds.height);
      PopupSelectionList popup=new PopupSelectionList(expressionText.getParent().getShell());
      popup.setItems(popupItems);
      String value=popup.open(rect);
      int selectionIndex=popup.getSelectionIndex();
      if (value != null) {
        String newValue=null;
        if (value.equals((actions[0]))) {
          List valueList=getSelectMemberValueList();
          if (valueList == null || valueList.size() == 0) {
            MessageDialog.openInformation(null,Messages.getString("String_Node_Str"),Messages.getString("String_Node_Str"));
          }
 else {
            SelectValueDialog dialog=new SelectValueDialog(PlatformUI.getWorkbench().getDisplay().getActiveShell(),Messages.getString("String_Node_Str"));
            dialog.setSelectedValueList(valueList);
            if (dialog.open() == IDialogConstants.OK_ID) {
              newValue=dialog.getSelectedExprValue();
            }
          }
        }
 else         if (value.equals(actions[1])) {
          ExpressionBuilder dialog=new ExpressionBuilder(PlatformUI.getWorkbench().getDisplay().getActiveShell(),(String)getValue());
          dialog.setExpressionProvier(provider);
          if (dialog.open() == IDialogConstants.OK_ID) {
            newValue=dialog.getResult();
          }
        }
 else         if (selectionIndex > 3) {
          newValue=ExpressionUtil.createJSParameterExpression(value);
        }
        if (newValue != null) {
          setValue(newValue);
        }
        expressionText.setFocus();
      }
    }
    public void widgetDefaultSelected(    SelectionEvent e){
    }
  }
);
  setValueValid(true);
  return editorComposite;
}

Fixed version (ground truth):
protected Control createControl(Composite parent){
  Composite editorComposite=new Composite(parent,getStyle());
  editorComposite.setLayout(new ExpressionCellLayout());
  expressionText=new Text(editorComposite,SWT.NONE);
  expressionText.addKeyListener(new KeyAdapter(){
    public void keyReleased(    KeyEvent e){
      keyReleaseOccured(e);
    }
  }
);
  expressionText.addSelectionListener(new SelectionAdapter(){
    public void widgetDefaultSelected(    SelectionEvent e){
    }
  }
);
  expressionText.addTraverseListener(new TraverseListener(){
    public void keyTraversed(    TraverseEvent e){
      if (e.detail == SWT.TRAVERSE_ESCAPE || e.detail == SWT.TRAVERSE_RETURN) {
        e.doit=false;
      }
    }
  }
);
  expressionText.addFocusListener(new FocusAdapter(){
    public void focusLost(    FocusEvent e){
      ExpressionValueCellEditor.this.focusLost();
    }
  }
);
  btnPopup=new Button(editorComposite,SWT.ARROW | SWT.DOWN);
  btnPopup.addSelectionListener(new SelectionListener(){
    public void widgetSelected(    SelectionEvent e){
      refreshList();
      Rectangle textBounds=expressionText.getBounds();
      Point pt=expressionText.toDisplay(textBounds.x,textBounds.y);
      Rectangle rect=new Rectangle(pt.x,pt.y,expressionText.getParent().getBounds().width,textBounds.height);
      PopupSelectionList popup=new PopupSelectionList(expressionText.getParent().getShell());
      popup.setItems(popupItems);
      String value=popup.open(rect);
      int selectionIndex=popup.getSelectionIndex();
      if (value != null) {
        String newValue=null;
        if (value.equals((actions[0]))) {
          List valueList=getSelectMemberValueList();
          if (valueList == null || valueList.size() == 0) {
            MessageDialog.openInformation(null,Messages.getString("String_Node_Str"),Messages.getString("String_Node_Str"));
          }
 else {
            SelectValueDialog dialog=new SelectValueDialog(PlatformUI.getWorkbench().getDisplay().getActiveShell(),Messages.getString("String_Node_Str"));
            dialog.setSelectedValueList(valueList);
            if (dialog.open() == IDialogConstants.OK_ID) {
              newValue=dialog.getSelectedExprValue();
            }
          }
        }
 else         if (selectionIndex > 3) {
          newValue=ExpressionUtil.createJSParameterExpression(value);
        }
        if (newValue != null) {
          setValue(newValue);
        }
        expressionText.setFocus();
      }
    }
    public void widgetDefaultSelected(    SelectionEvent e){
    }
  }
);
  setValueValid(true);
  return editorComposite;
}