<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<p>Seasiders<br>
</p>
<p>From time to time we get walkbacks on our production servers when
users want to login/create a new session due to failed
cleanup/unregister of old sessions.</p>
<p>Here's an excerpt from the walkback (VA Smalltalk):</p>
<p><tt>MessageNotUnderstood class(Exception
class)>>#signalWith:</tt><tt><br>
</tt><tt> receiver = MessageNotUnderstood</tt><tt><br>
</tt><tt> arg1 = (nil Message (#unregisterAt:,
('PZv9N5QPtkzYQMvH')))</tt><tt><br>
</tt><tt>UndefinedObject(Object)>>#doesNotUnderstand:</tt><tt><br>
</tt><tt> receiver = nil</tt><tt><br>
</tt><tt> arg1 = Message (#unregisterAt:, ('PZv9N5QPtkzYQMvH'))</tt><tt><br>
</tt><tt>KontolinoSession(WASession)>>#unregister</tt><tt><br>
</tt><tt> receiver = a KontolinoSession</tt><tt><br>
</tt><tt>KontolinoSession>>#unregister</tt><tt><br>
</tt><tt> receiver = a KontolinoSession</tt><br>
</p>
<p>Looking at WASession>>#unregister it is clear that the
variable @parent isNil and therefor unregister cannot work. <br>
</p>
<p>Now I am wondering</p>
<ul>
<li>how could @parent become nil? <br>
The only thing I can think of is a user clicking on "logout"
twice. The logs of our application, however, don't support this
thesis...<br>
</li>
<li>is this a (known and/or even fixed) bug in Seaside or our
code? We haven't implemented any access to the @parent
variable...<br>
</li>
<li>is it a good workaround to intrudoce a notNil check in our
WASession subclass' #unregister method before sending super
unregister? <br>
We will try this of course because it is not a good marketing
gag to greet users with an error screen instead of a login form<br>
</li>
</ul>
<p><br>
</p>
<p>Any hints, ideas, requests for more details are welcome.</p>
<p><br>
</p>
<p>Joachim <br>
</p>
<pre class="moz-signature" cols="72">--
-----------------------------------------------------------------------
Objektfabrik Joachim Tuchel <a class="moz-txt-link-freetext" href="mailto:jtuchel@objektfabrik.de">mailto:jtuchel@objektfabrik.de</a>
Fliederweg 1 <a class="moz-txt-link-freetext" href="http://www.objektfabrik.de">http://www.objektfabrik.de</a>
D-71640 Ludwigsburg <a class="moz-txt-link-freetext" href="http://joachimtuchel.wordpress.com">http://joachimtuchel.wordpress.com</a>
Telefon: +49 7141 56 10 86 0 Fax: +49 7141 56 10 86 1
</pre>
</body>
</html>