Merge branch 'MDL-56690-master' of git://github.com/damyon/moodle

theme/boost/scss/moodle/undo.scss

@@ -163,3 +163,9 @@ body:not(.jsenabled) .langmenu:hover > .dropdown-menu,
 ol {
     margin: 0 0 $line-height-base / 2 2.5em;
 }
+
+// Set menus in the fixed header to scroll vertically when they are longer than the page.
+.navbar-static-top .dropdown .dropdown-menu {
+    max-height: calc(100vh - #{$navbar-height});
+    overflow-y: auto;
+}