Bug 1821104: Disable logout link on click

So that it can't be clicked again during logout process

behatnotneeded

Change-Id: I3951fa174b933e3c730e66de49fd18e559e6d88a
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>

htdocs/theme/raw/sass/layout/nav/_main-nav.scss

@@ -91,6 +91,10 @@
                 text-decoration:none;
                 color: $navbar-default-link-hover-color;
             }
+            &.disabled {
+                color: $btn-link-disabled-color;
+                cursor: not-allowed;
+            }
             @include media-breakpoint-up(md) {
                 border: 1px solid $navbar-default-border;
             }

htdocs/theme/raw/templates/header/navigation.tpl

@@ -162,10 +162,20 @@
         </li>
         {/foreach}
         <li class="btn-logout has-icon">
-            <a href="{$WWWROOT}?logout" accesskey="l">
+            <a id="logoutbutton" href="{$WWWROOT}?logout" accesskey="l">
                 <span class="icon icon-sign-out" role="presentation" aria-hidden="true"></span>
                 <span class="nav-title">{str tag="logout"}</span>
             </a>
+            <script>
+            $('#logoutbutton').click(function(e) {
+                if ($(this).hasClass('disabled')) {
+                    e.preventDefault();
+                    return false;
+                }
+                $(this).addClass('disabled');
+                return true;
+            });
+            </script>
         </li>
         {if $USERMASQUERADING && $LOGGEDIN}
         <li class="backto-be-admin has-icon">