From: Szabolcs Szasz <sz@...>
Date: 2002-10-09T02:54:03+09:00
Subject: Session stub & a bug (Was: Update on HTTP session handling in Ruby?)

(Just for the record, in case another newbie tries to find something 
like this in the archive...)

> Does this mean that the current cgi/session is just fine 
> now, or people gave up the quest for the Holy Grail?
> (CGI::Session used to be a little handicapped compared 
> to e.g. PHP's, AFAIK.)

I had constant problems with sessions (but that's just usual for me, 
having constant problems with things working fine for others. ;) ).

1. Minimal sessioned .rhtml page I could come up with:

    <%
    require 'cgi/session'
    session = CGI::Session.new( cgi = CGI.new('html4') )
    begin

        session['var'] = 'xxx'

    #
    # You WILL use sessions from mod_ruby, so don't forget this
    # for closing it (ie. closing the session-file, by default).
    #
    # See: http://www.modruby.net/doc/faq.en.html#label:14
    #
    ensure
        cgi.header    # *NASTY* hack to flush stuff to actually make the
                            # session live -- needed only for creating a session.
                            # Any nicer way, please?? (I DO NOT want to 
                            # clutter my "main stuff" (above) with cgi.calls, as 
                            # I only need sessions, and conceptually, CGI has 
                            # nothing to do with that. I want a clean page...)
        session.close
    end
%>


2. There is a fatal bug in cgi/session.rb (class FileStore):

If you do not use or set any session[] variables, hitting reload 
on the page will kill the script (ruby 1.6.7):

[Tue Oct  8 18:53:36 2002] [error] mod_ruby: error in ruby
/usr/lib/ruby/1.6/cgi/session.rb:123:in `update': undefined method `each' for nil (NameError)
        from /usr/lib/ruby/1.6/cgi/session.rb:130:in `close'
        from /usr/lib/ruby/1.6/cgi/session.rb:81:in `close'
        from /tmp/index.rhtml.3335.0:11
        from /usr/lib/ruby/1.6/apache/eruby-run.rb:112:in `load'
        from /usr/lib/ruby/1.6/apache/eruby-run.rb:112:in `run'
        from /usr/lib/ruby/1.6/apache/eruby-run.rb:78:in `handler'
        from ruby:0

The problem: FileStore.update assumes @hash is never nil, 
but FileStore.initialize does NOT initialize @hash if a file 
for the current session-ID already exists...

Cheers,
Sz.