--- a/browser/devtools/inspector/breadcrumbs.js
+++ b/browser/devtools/inspector/breadcrumbs.js
@@ -694,13 +694,13 @@ HTMLBreadcrumbs.prototype = {
       this.scroll();
       this.inspector.emit("breadcrumbs-updated", this.selection.nodeFront);
       doneUpdating();
     }).then(null, err => {
       doneUpdating(this.selection.nodeFront);
       this.selectionGuardEnd(err);
     });
   }
-}
+};
 
 XPCOMUtils.defineLazyGetter(this, "DOMUtils", function () {
   return Cc["@mozilla.org/inspector/dom-utils;1"].getService(Ci.inIDOMUtils);
 });

--- a/browser/devtools/markupview/markup-view.js
+++ b/browser/devtools/markupview/markup-view.js
@@ -1540,18 +1540,16 @@ MarkupContainer.prototype = {
       if (firstChild.container) {
         firstChild.container.destroy();
       }
       this.children.removeChild(firstChild);
     }
 
     // Remove event listeners
     this.elt.removeEventListener("dblclick", this._onToggle, false);
-    this.elt.removeEventListener("mouseover", this._onMouseOver, false);
-    this.elt.removeEventListener("mouseout", this._onMouseOut, false);
     this.elt.removeEventListener("mousedown", this._onMouseDown, false);
     this.expander.removeEventListener("click", this._onToggle, false);
 
     // Destroy my editor
     this.editor.destroy();
   }
 };
 

--- a/browser/devtools/sourceeditor/editor.js
+++ b/browser/devtools/sourceeditor/editor.js
@@ -27,18 +27,17 @@ const L10N = Services.strings.createBund
 // CM_STYLES, CM_SCRIPTS and CM_IFRAME represent the HTML,
 // JavaScript and CSS that is injected into an iframe in
 // order to initialize a CodeMirror instance.
 
 const CM_STYLES   = [
   "chrome://browser/skin/devtools/common.css",
   "chrome://browser/content/devtools/codemirror/codemirror.css",
   "chrome://browser/content/devtools/codemirror/dialog.css",
-  "chrome://browser/content/devtools/codemirror/mozilla.css",
-  "chrome://browser/content/devtools/codemirror/foldgutter.css"
+  "chrome://browser/content/devtools/codemirror/mozilla.css"
 ];
 
 const CM_SCRIPTS  = [
   "chrome://browser/content/devtools/theme-switching.js",
   "chrome://browser/content/devtools/codemirror/codemirror.js",
   "chrome://browser/content/devtools/codemirror/dialog.js",
   "chrome://browser/content/devtools/codemirror/searchcursor.js",
   "chrome://browser/content/devtools/codemirror/search.js",

--- a/browser/devtools/styleinspector/style-inspector.js
+++ b/browser/devtools/styleinspector/style-inspector.js
@@ -130,17 +130,17 @@ RuleViewTool.prototype = {
 
     this.view.destroy();
 
     delete this.outerIFrame;
     delete this.view;
     delete this.doc;
     delete this.inspector;
   }
-}
+};
 
 function ComputedViewTool(aInspector, aWindow, aIFrame)
 {
   this.inspector = aInspector;
   this.window = aWindow;
   this.document = aWindow.document;
   this.outerIFrame = aIFrame;
   this.view = new ComputedView.CssHtmlTree(this, aInspector.pageStyle);

--- a/toolkit/devtools/server/actors/inspector.js
+++ b/toolkit/devtools/server/actors/inspector.js
@@ -1189,17 +1189,17 @@ var WalkerActor = protocol.ActorClass({
     if (maxNodes == -1) {
       maxNodes = Number.MAX_VALUE;
     }
 
     // We're going to create a few document walkers with the same filter,
     // make it easier.
     let filteredWalker = (node) => {
       return documentWalker(node, this.rootWin, options.whatToShow);
-    }
+    };
 
     // Need to know the first and last child.
     let rawNode = node.rawNode;
     let firstChild = filteredWalker(rawNode).firstChild();
     let lastChild = filteredWalker(rawNode).lastChild();
 
     if (!firstChild) {
       // No children, we're done.
@@ -1380,17 +1380,25 @@ var WalkerActor = protocol.ActorClass({
   /**
    * Return a NodeListActor with all nodes that match the given selector.
    * See https://developer.mozilla.org/en-US/docs/Web/API/Element.querySelectorAll
    *
    * @param NodeActor baseNode
    * @param string selector
    */
   querySelectorAll: method(function(baseNode, selector) {
-    return new NodeListActor(this, baseNode.rawNode.querySelectorAll(selector));
+    let nodeList = null;
+
+    try {
+      nodeList = baseNode.rawNode.querySelectorAll(selector);
+    } catch(e) {
+      // Bad selector. Do nothing as the selector can come from a searchbox.
+    }
+
+    return new NodeListActor(this, nodeList);
   }, {
     request: {
       node: Arg(0, "domnode"),
       selector: Arg(1)
     },
     response: {
       list: RetVal("domnodelist")
     }