diff --git a/toolkit/content/widgets/tree.xml b/toolkit/content/widgets/tree.xml
index bacea636db..ec88a1e09d 100644
--- a/toolkit/content/widgets/tree.xml
+++ b/toolkit/content/widgets/tree.xml
@@ -737,6 +737,7 @@
       </handler>
       <handler event="MozSwipeGesture" preventdefault="true">
         <![CDATA[
+          if (!this.view) return;
           // Figure out which row to show
           let targetRow = 0;
 
@@ -756,6 +757,7 @@
       <handler event="focus">
         <![CDATA[
           this.treeBoxObject.focused = true;
+          if (!this.view) return;
           if (this.currentIndex == -1 && this.view.rowCount > 0) {
             this.currentIndex = this.treeBoxObject.getFirstVisibleRow();
           }
@@ -778,7 +780,7 @@
       <!-- Use F2 key to enter text editing. -->
       <handler event="keydown" keycode="VK_F2">
         <![CDATA[
-          if (!this._cellSelType)
+          if (!this.view || !this._cellSelType)
             return;
           var row = this.currentIndex;
           var column = this.view.selection.currentColumn;
@@ -900,112 +902,112 @@
       </handler>
       <handler event="keydown" keycode="VK_UP" modifiers="accel any">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveByOffset(-1, 0, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_DOWN" modifiers="accel any">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveByOffset(1, this.view.rowCount - 1, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_UP" modifiers="accel any, shift">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveByOffsetShift(-1, 0, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_DOWN" modifiers="accel any, shift">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveByOffsetShift(1, this.view.rowCount - 1, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_PAGE_UP" modifiers="accel any">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveByPage(-1, 0, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_PAGE_DOWN" modifiers="accel any">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveByPage(1, this.view.rowCount - 1, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_PAGE_UP" modifiers="accel any, shift">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveByPageShift(-1, 0, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_PAGE_DOWN" modifiers="accel any, shift">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveByPageShift(1, this.view.rowCount - 1, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_HOME" modifiers="accel any">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveToEdge(0, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_END" modifiers="accel any">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveToEdge(this.view.rowCount - 1, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_HOME" modifiers="accel any, shift">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveToEdgeShift(0, event);
         ]]>
       </handler>
       <handler event="keydown" keycode="VK_END" modifiers="accel any, shift">
         <![CDATA[
-          if (this._editingColumn)
+          if (!this.view || this._editingColumn)
             return;
           _moveToEdgeShift(this.view.rowCount - 1, event);
         ]]>
       </handler>
       <handler event="keypress">
         <![CDATA[
-         if (this._editingColumn)
-           return;
+          if (!this.view || this._editingColumn)
+            return;
 
-         if (event.charCode == ' '.charCodeAt(0)) {
-           var c = this.currentIndex;
-           if (!this.view.selection.isSelected(c) ||
-               (!this.view.selection.single && this._isAccelPressed(event))) {
-             this.view.selection.toggleSelect(c);
-             event.preventDefault();
-           }
-         }
-         else if (!this.disableKeyNavigation && event.charCode > 0 &&
-                  !event.altKey && !this._isAccelPressed(event) &&
-                  !event.metaKey && !event.ctrlKey) {
-           var l = this._keyNavigate(event);
-           if (l >= 0) {
-             this.view.selection.timedSelect(l, this._selectDelay);
-             this.treeBoxObject.ensureRowIsVisible(l);
-           }
-           event.preventDefault();
-         }
-         ]]>
+          if (event.charCode == ' '.charCodeAt(0)) {
+            var c = this.currentIndex;
+            if (!this.view.selection.isSelected(c) ||
+                (!this.view.selection.single && this._isAccelPressed(event))) {
+              this.view.selection.toggleSelect(c);
+              event.preventDefault();
+            }
+          }
+          else if (!this.disableKeyNavigation && event.charCode > 0 &&
+                   !event.altKey && !this._isAccelPressed(event) &&
+                   !event.metaKey && !event.ctrlKey) {
+            var l = this._keyNavigate(event);
+            if (l >= 0) {
+              this.view.selection.timedSelect(l, this._selectDelay);
+              this.treeBoxObject.ensureRowIsVisible(l);
+            }
+            event.preventDefault();
+          }
+          ]]>
       </handler>
     </handlers>
   </binding>
@@ -1558,4 +1560,4 @@
       </handler>
     </handlers>
   </binding>
-</bindings>
+</bindings>
\ No newline at end of file