--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -3006,19 +3006,20 @@ function getMarkupDocumentViewer()
  *       which performs the same function, but for embedded clients that
  *       don't use a XUL/JS layer. It is important that the logic of
  *       these two routines be kept more or less in sync.
  *       (pinkerton)
  **/
 function FillInHTMLTooltip(tipElement)
 {
   var retVal = false;
-  // Don't show the tooltip if the tooltip node is a XUL element or a document.
+  // Don't show the tooltip if the tooltip node is a XUL element, a document or is disconnected.
   if (tipElement.namespaceURI == "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" ||
-      !tipElement.ownerDocument)
+      !tipElement.ownerDocument ||
+      tipElement.ownerDocument.compareDocumentPosition(tipElement) == document.DOCUMENT_POSITION_DISCONNECTED)
     return retVal;
 
   const XLinkNS = "http://www.w3.org/1999/xlink";
 
 
   var titleText = null;
   var XLinkTitleText = null;
   var SVGTitleText = null;
@@ -3036,20 +3037,20 @@ function FillInHTMLTooltip(tipElement)
     // If the element is barred from constraint validation or valid,
     // the validation message will be the empty string.
     titleText = tipElement.validationMessage;
   }
 
   while (!titleText && !XLinkTitleText && !SVGTitleText && tipElement) {
     if (tipElement.nodeType == Node.ELEMENT_NODE) {
       titleText = tipElement.getAttribute("title");
-      if ((tipElement instanceof HTMLAnchorElement && tipElement.href) ||
-          (tipElement instanceof HTMLAreaElement && tipElement.href) ||
-          (tipElement instanceof HTMLLinkElement && tipElement.href) ||
-          (tipElement instanceof SVGAElement && tipElement.hasAttributeNS(XLinkNS, "href"))) {
+      if ((tipElement instanceof HTMLAnchorElement ||
+           tipElement instanceof HTMLAreaElement ||
+           tipElement instanceof HTMLLinkElement ||
+           tipElement instanceof SVGAElement) && tipElement.href) {
         XLinkTitleText = tipElement.getAttributeNS(XLinkNS, "title");
       }
       if (lookingForSVGTitle &&
           (!(tipElement instanceof SVGElement) ||
            tipElement.parentNode.nodeType == Node.DOCUMENT_NODE)) {
         lookingForSVGTitle = false;
       }
       if (lookingForSVGTitle) {