Merged r11750 from trunk (#12650).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/branches/2.3-stable@11751 e93f8b46-1217-0410-a6f0-8f06a7374b81

public/javascripts/context_menu.js

@@ -186,7 +186,7 @@ function contextMenuCheckSelectionBox(tr, checked) {
 function contextMenuClearDocumentSelection() {
   // TODO
   if (document.selection) {
-    document.selection.clear(); // IE
+    document.selection.empty(); // IE
   } else {
     window.getSelection().removeAllRanges();
   }