Program: 91860
Project: 91860
Buggy source:
/** 
 * Downloads a trace from the remote host to the given project.
 * @param trace - trace information of trace to import
 * @param project - project to import to
 * @param monitor - a progress monitor
 * @throws ExecutionException
 */
private static void downloadTrace(ImportFileInfo trace,IProject project,IProgressMonitor monitor) throws ExecutionException {
  try {
    IRemoteFileSubSystem fsss=trace.getImportFile().getParentRemoteFileSubSystem();
    IFolder traceFolder=project.getFolder(TmfTracesFolder.TRACES_FOLDER_NAME);
    if (!traceFolder.exists()) {
      throw new ExecutionException(Messages.TraceControl_ImportDialogInvalidTracingProject + "String_Node_Str" + TmfTracesFolder.TRACES_FOLDER_NAME+ "String_Node_Str");
    }
    IFolder destinationFolder=trace.getDestinationFolder();
    TraceUtils.createFolder(destinationFolder,monitor);
    String traceName=trace.getLocalTraceName();
    IFolder folder=destinationFolder.getFolder(traceName);
    if (folder.exists()) {
      if (!trace.isOverwrite()) {
        throw new ExecutionException(Messages.TraceControl_ImportDialogTraceAlreadyExistError + "String_Node_Str" + traceName);
      }
    }
 else {
      folder.create(true,true,null);
    }
    IRemoteFile[] sources=fsss.list(trace.getImportFile(),IFileService.FILE_TYPE_FILES,new NullProgressMonitor());
    SubMonitor subMonitor=SubMonitor.convert(monitor,sources.length);
    subMonitor.beginTask(Messages.TraceControl_DownloadTask,sources.length);
    for (int i=0; i < sources.length; i++) {
      if (subMonitor.isCanceled()) {
        monitor.setCanceled(true);
        return;
      }
      String destination=folder.getLocation().addTrailingSeparator().append(sources[i].getName()).toString();
      subMonitor.setTaskName(Messages.TraceControl_DownloadTask + ' ' + traceName+ '/'+ sources[i].getName());
      fsss.download(sources[i],destination,null,subMonitor.newChild(1));
    }
  }
 catch (  SystemMessageException e) {
    throw new ExecutionException(e.toString(),e);
  }
catch (  CoreException e) {
    throw new ExecutionException(e.toString(),e);
  }
}

Fixed version (ground truth):
/** 
 * Downloads a trace from the remote host to the given project.
 * @param trace - trace information of trace to import
 * @param project - project to import to
 * @param monitor - a progress monitor
 * @throws ExecutionException
 */
private static void downloadTrace(ImportFileInfo trace,IProject project,IProgressMonitor monitor) throws ExecutionException {
  try {
    IRemoteFileSubSystem fsss=trace.getImportFile().getParentRemoteFileSubSystem();
    IFolder traceFolder=project.getFolder(TmfTracesFolder.TRACES_FOLDER_NAME);
    if (!traceFolder.exists()) {
      throw new ExecutionException(Messages.TraceControl_ImportDialogInvalidTracingProject + "String_Node_Str" + TmfTracesFolder.TRACES_FOLDER_NAME+ "String_Node_Str");
    }
    IFolder destinationFolder=trace.getDestinationFolder();
    TraceUtils.createFolder(destinationFolder,monitor);
    String traceName=trace.getLocalTraceName();
    IFolder folder=destinationFolder.getFolder(traceName);
    if (folder.exists()) {
      if (!trace.isOverwrite()) {
        throw new ExecutionException(Messages.TraceControl_ImportDialogTraceAlreadyExistError + "String_Node_Str" + traceName);
      }
    }
 else {
      folder.create(true,true,null);
    }
    IRemoteFile[] sources=fsss.list(trace.getImportFile(),IFileService.FILE_TYPE_FILES,new NullProgressMonitor());
    SubMonitor subMonitor=SubMonitor.convert(monitor,sources.length);
    subMonitor.beginTask(Messages.TraceControl_DownloadTask,sources.length);
    for (int i=0; i < sources.length; i++) {
      if (subMonitor.isCanceled()) {
        monitor.setCanceled(true);
        return;
      }
      String destination=folder.getLocation().addTrailingSeparator().append(sources[i].getName()).toOSString();
      subMonitor.setTaskName(Messages.TraceControl_DownloadTask + ' ' + traceName+ '/'+ sources[i].getName());
      fsss.download(sources[i],destination,null,subMonitor.newChild(1));
    }
  }
 catch (  SystemMessageException e) {
    throw new ExecutionException(e.toString(),e);
  }
catch (  CoreException e) {
    throw new ExecutionException(e.toString(),e);
  }
}