Program: 130129
Project: 130129
Buggy source:
private void viewSheet(final String sheetName){
  ProgressMonitorDialog dialog=new ProgressMonitorDialog(viewer.getTable().getShell());
  try {
    dialog.run(true,false,new IRunnableWithProgress(){
      public void run(      IProgressMonitor monitor) throws InvocationTargetException, InterruptedException {
        monitor.beginTask("String_Node_Str",IProgressMonitor.UNKNOWN);
        getConnection().setSheetName(sheetName);
        Display.getDefault().syncExec(new Runnable(){
          @SuppressWarnings("String_Node_Str") public void run(){
            disposeExistColumns();
            final List<String[]> input=excelReader.readSheet(sheetName);
            if (input == null) {
              viewer.setInput(getEmptyInput());
              return;
            }
            int maxLength=0;
            for (int i=0, z=input.size(); i < z; i++) {
              int x=input.get(i).length;
              if (x > maxLength) {
                maxLength=x;
              }
            }
            String[] names=ExcelReader.getColumnsTitle(maxLength);
            List columns=getConnection().getSheetColumns();
            columns.clear();
            for (            String name : names) {
              columns.add(name);
              TableColumn tableColumn=new TableColumn(viewer.getTable(),SWT.NONE);
              tableColumn.setText(name);
              tableColumn.setWidth(WIDTH);
            }
            viewer.setInput(input);
          }
        }
);
        monitor.done();
      }
    }
);
  }
 catch (  InvocationTargetException e) {
    updateErrorStatus(e.getMessage());
  }
catch (  InterruptedException e) {
    updateErrorStatus(e.getMessage());
  }
}

Fixed version (ground truth):
private void viewSheet(final String sheetName){
  ProgressMonitorDialog dialog=new ProgressMonitorDialog(viewer.getTable().getShell());
  errorSet.remove(ERRORSET_EXCELPREVIEW);
  try {
    dialog.run(true,false,new IRunnableWithProgress(){
      @Override public void run(      IProgressMonitor monitor) throws InvocationTargetException, InterruptedException {
        monitor.beginTask("String_Node_Str",IProgressMonitor.UNKNOWN);
        getConnection().setSheetName(sheetName);
        Display.getDefault().syncExec(new Runnable(){
          @Override @SuppressWarnings("String_Node_Str") public void run(){
            disposeExistColumns();
            final List<String[]> input=excelReader.readSheet(sheetName);
            if (input == null) {
              viewer.setInput(getEmptyInput());
              return;
            }
            int maxLength=0;
            for (int i=0, z=input.size(); i < z; i++) {
              int x=input.get(i).length;
              if (x > maxLength) {
                maxLength=x;
              }
            }
            String[] names=ExcelReader.getColumnsTitle(maxLength);
            List columns=getConnection().getSheetColumns();
            columns.clear();
            for (            String name : names) {
              columns.add(name);
              TableColumn tableColumn=new TableColumn(viewer.getTable(),SWT.NONE);
              tableColumn.setText(name);
              tableColumn.setWidth(WIDTH);
            }
            viewer.setInput(input);
          }
        }
);
        monitor.done();
      }
    }
);
  }
 catch (  InvocationTargetException e) {
    errorSet.add(ERRORSET_EXCELPREVIEW);
    updateErrorStatus(e.getMessage());
  }
catch (  InterruptedException e) {
    errorSet.add(ERRORSET_EXCELPREVIEW);
    updateErrorStatus(e.getMessage());
  }
}