I have set the cookie expire time to 1 year, and Rails seems to send the
correct header line:
Set-Cookie: _session_id=ffd03d0308c0b5059b9e13448468d91c; path=/;
expires=Mon, 20 Nov 2006 20:32:02 GMT
Still every time I quit Firefox the cookie is gone, and in the cookie
list in the preferences it says “valid until end of session”.
Because it’s a session, not a normal cookie. According to this thread
they are always stored in memory and thus only persistent inside a
single browser session: http://article.gmane.org/
gmane.comp.lang.ruby.rails/11288/