openproject/app/views/common/_favicons.html.erb

<% unless (EnterpriseToken.allows_to?(:define_custom_style) && CustomStyle.try(:current).present? && CustomStyle.current.favicon.present?) %>
  <%= favicon_link_tag OpenProject::Design.favicon_asset_path %>
<% end %>

<% unless (EnterpriseToken.allows_to?(:define_custom_style) && CustomStyle.try(:current).present? && CustomStyle.current.touch_icon.present?) %>
  <%# In the future we can add more sizes should we see 404 errors in the logs. %>
  <%= favicon_link_tag "apple-touch-icon-120x120.png", rel: 'apple-touch-icon',
                                                       type: 'image/png',
                                                       sizes: "120x120" %>
<% end %>