Strange ESI behaviour if page is set to no-cache


Well-Known Member
I am validating a new developed cache plugin for application where is no cache plugin available. In the header of this application there is a toolbar that contains shopping cart, an icon that shows the number of items that has been added to wishlist and an icon with submenu that is displayed if this icon is clicked. Content of this submenu depends on if user is logged in or not. (Login, logoff and other links). For this submenu I punched an ESI whole that works as it should, but only if the requested URL is not no-cache. Whenever I request a URL like account pages, that are all no-cache, this submenu is empty. This submenu is defined as private, has a TTL of 360 seconds and an unique cache tag, but it doesn't matter if TTL is defined or if it is no-cache. I have also defined a very cookie if user is logged in, so logged in users get different cache.

The question is, is this strange looking behaviour a bug or part of design?