Redmine

I'm attaching a patch to fix this issue.

diff --git a/app/views/layouts/base.html.erb b/app/views/layouts/base.html.erb
index 4b7b401c1..62e23abd1 100644
--- a/app/views/layouts/base.html.erb
+++ b/app/views/layouts/base.html.erb
@@ -93,8 +93,12 @@
     <div id="main-menu" class="tabs">
         <%= render_main_menu(@project) %>
         <div class="tabs-buttons" style="display:none;">
-            <button class="tab-left" onclick="moveTabLeft(this); return false;"></button>
-            <button class="tab-right" onclick="moveTabRight(this); return false;"></button>
+            <button class="tab-left icon-only" onclick="moveTabLeft(this); return false;">
+              <%= sprite_icon "angle-left" %>
+            </button>
+            <button class="tab-right icon-only" onclick="moveTabRight(this); return false;">
+              <%= sprite_icon "angle-right" %>
+            </button>
         </div>
     </div>
     <% end %>

Since this issue was caused by r24029, I have committed the fix as part of #43206 in r24048.

Thank you for catching and fixing this issue.