Bug 359541 - 'View Selection Source' broken.

browser/base/content/nsContextMenu.js

@@ -665,9 +665,9 @@ nsContextMenu.prototype = {
     // are mutually exclusive, with the precedence given to the selection
     // when there is one
     var reference = null;
-    if (context == "selection")
+    if (aContext == "selection")
       reference = focusedWindow.getSelection();
-    else if (context == "mathml")
+    else if (aContext == "mathml")
       reference = this.target;
     else
       throw "not reached";