Fix TypeError exception when scrolling while the buffer is being loaded

  Fixes issue 866

Author: zklinger

common/content/buffer.js

@@ -1010,11 +1010,14 @@ const Buffer = Module("buffer", {
     getFocusedWindow: function (win) {
         win = win || config.browser.contentWindow;
         let elem = win.document.activeElement;
-        let doc;
-        while (doc = elem.contentDocument) {
-            elem = doc.activeElement;
-        }
-        return elem.ownerDocument.defaultView;
+        if (elem) {
+            let doc;
+            while (doc = elem.contentDocument) {
+                elem = doc.activeElement;
+            }
+            return elem.ownerDocument.defaultView;
+        } else
+            return win;
     },
 
     setZoom: function setZoom(value, fullZoom) {
@@ -1067,7 +1070,7 @@ const Buffer = Module("buffer", {
             pos = "scrollLeft", maxPos = "scrollLeftMax", clientSize = "clientWidth";
 
         function find(elem) {
-            if (!(elem instanceof Element))
+            if (elem && !(elem instanceof Element))
                 elem = elem.parentNode;
 
             for (; elem && elem.parentNode instanceof Element; elem = elem.parentNode) {

vimperator/NEWS

@@ -1,7 +1,8 @@
-2013-XX-XX:
+2013-XX-XX
     * version 3.8
     * Add "ssl" field shows SSL connection icon to "status" option (default: off)
     * Tabs count and it's index in status-line are changed to the current group's tabs count and it's index.
+    * Fixed "TypeError: elem is null" error when scrolling while the page is being loaded
 
 2013-05-22:
     * version 3.7.1