[cache] fix a cache issue with an entity created without relation cache prefill
Prefilling the relation cache has its benefits sometimes, but for
massive imports it may be a memory hog.
The caches should be kept coherent even if there was no prefill.
Closes #3828155.
.. _ajax:
Ajax
----
CubicWeb provides a few helpers to facilitate *javascript <-> python* communications.
You can, for instance, register some python functions that will become
callable from javascript through ajax calls. All the ajax URLs are handled
by the :class:`cubicweb.web.views.ajaxcontroller.AjaxController` controller.
.. automodule:: cubicweb.web.views.ajaxcontroller