For a none logged-in user :
When using search many times, comes a time when search history stops (around 15).
When not logged-in, search history is stored in a cookie and this cookie is full.
Its size is limited by browser at 4Ko.
Search history could erase old searches to keep space in cookie.
Created attachment 3481 [details] [review]
Works as expected. Signed off.
Pushed, please test