rem: var ds = getBrowser().docShell; 
add: try { var ds = getBrowser().docShell; } catch(e) {   return; } 
context: function changeSelectionColor(aAttention){  var ds = getBrowser().docShell;  var dsEnum = ds.getDocShellEnumerator(Components.interfaces.nsIDocShellTreeItem.typeContent,                                        Components.interfaces.nsIDocShell.ENUMERATE_FORWARDS);  while (dsEnum.hasMoreElements()) {    ds = dsEnum.getNext().QueryInterface(Components.interfaces.nsIDocShell);    var controller = getSelectionControllerForFindToolbar(ds);    if (!controller)      continue;    const selCon = Components.interfaces.nsISelectionController;    controller.setDisplaySelection(aAttention? selCon.SELECTION_ATTENTION : selCon.SELECTION_ON);  }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/cce9f2e13a16a36529594d8a177703c27ed84d4b/findBar.js/buggy/toolkit/components/typeaheadfind/content/findBar.js