Program: 188443
Project: 188443
Buggy source:
@Override public Widget createActionsLayout(SelectedItems<IndexedFile> files,AsyncCallback<ActionImpact> callback){
  FlowPanel layout=createLayout();
  addTitle(layout,messages.sidebarFoldersFilesTitle(),files,null,FileAction.DOWNLOAD,FileAction.RENAME,FileAction.MOVE,FileAction.UPLOAD_FILES,FileAction.CREATE_FOLDER,FileAction.REMOVE);
  addButton(layout,messages.downloadButton(),FileAction.DOWNLOAD,files,ActionImpact.NONE,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.renameButton(),FileAction.RENAME,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.moveButton(),FileAction.MOVE,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.uploadFilesButton(),FileAction.UPLOAD_FILES,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.createFolderButton(),FileAction.CREATE_FOLDER,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.removeButton(),FileAction.REMOVE,files,ActionImpact.DESTROYED,callback,"String_Node_Str","String_Node_Str");
  addTitle(layout,messages.preservationTitle(),files,"String_Node_Str",FileAction.NEW_PROCESS,FileAction.IDENTIFY_FORMATS,FileAction.SHOW_EVENTS,FileAction.SHOW_RISKS);
  addButton(layout,messages.newProcessPreservation(),FileAction.NEW_PROCESS,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.identifyFormatsButton(),FileAction.IDENTIFY_FORMATS,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.preservationEvents(),FileAction.SHOW_EVENTS,files,ActionImpact.NONE,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.preservationRisks(),FileAction.SHOW_RISKS,files,ActionImpact.NONE,callback,"String_Node_Str","String_Node_Str");
  return layout;
}

Fixed version (ground truth):
@Override public Widget createActionsLayout(SelectedItems<IndexedFile> files,AsyncCallback<ActionImpact> callback){
  FlowPanel layout=createLayout();
  addTitle(layout,messages.sidebarFoldersFilesTitle(),files,FileAction.DOWNLOAD,FileAction.RENAME,FileAction.MOVE,FileAction.UPLOAD_FILES,FileAction.CREATE_FOLDER,FileAction.REMOVE);
  addButton(layout,messages.downloadButton(),FileAction.DOWNLOAD,files,ActionImpact.NONE,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.renameButton(),FileAction.RENAME,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.moveButton(),FileAction.MOVE,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.uploadFilesButton(),FileAction.UPLOAD_FILES,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.createFolderButton(),FileAction.CREATE_FOLDER,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.removeButton(),FileAction.REMOVE,files,ActionImpact.DESTROYED,callback,"String_Node_Str","String_Node_Str");
  addTitle(layout,messages.preservationTitle(),files,"String_Node_Str",FileAction.NEW_PROCESS,FileAction.IDENTIFY_FORMATS,FileAction.SHOW_EVENTS,FileAction.SHOW_RISKS);
  addButton(layout,messages.newProcessPreservation(),FileAction.NEW_PROCESS,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.identifyFormatsButton(),FileAction.IDENTIFY_FORMATS,files,ActionImpact.UPDATED,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.preservationEvents(),FileAction.SHOW_EVENTS,files,ActionImpact.NONE,callback,"String_Node_Str","String_Node_Str");
  addButton(layout,messages.preservationRisks(),FileAction.SHOW_RISKS,files,ActionImpact.NONE,callback,"String_Node_Str","String_Node_Str");
  return layout;
}