GadgetGrep: Escape user input

gadget/gadget_cribjs_page_grep.js

@@ -21,6 +21,7 @@
   function displayURLList(gadget, event) {
     var url_list = [],
       grep_pattern = gadget.props.element.querySelector(".search-pattern").value;
+    grep_pattern = grep_pattern.replace(new RegExp(/[-\/\\^$*+?.()|[\]{}]/g), '\\$&');
     return new RSVP.Queue()
     .push(function () {
         return gadget.crib_sw_allDocs();