[Simplecaptcha-usage] Internet Explorer 8 and sessions

[<Oli...@co...>]

Hello,

I have implemented the SimpleCaptcha in my JSP pages, as described here:

  http://simplecaptcha.sourceforge.net/installing.html

It works well with IE7, Firefox, Safari, Opera.

But I noticed that it does not work with IE8: an Exception is thrown, IIRC in the method

  ...
  if (captcha.isCorrect(answer)) { ... }

I don't have my code at hand here right now, but I remember the exception sais something like "The response is already commited, can't modify it."

The same also happens when I try to run the example code:

  http://sourceforge.net/projects/simplecaptcha/files/SimpleCaptcha/1.1.1/sc.war/download

I am not very familiar with the IE8, but I know it has some new feature called "Privacy Mode" (or whatever), which might or might not have an impact on this issue (I haven't checked whether it is enabled or disabled in my case, I just stumbled over it when googling for "IE8 broken session" or so. I also came across

  http://blogs.msdn.com/ie/archive/2009/05/06/session-cookies-sessionstorage-and-ie8.aspx

which talks about "session merging".

The fact that also JCaptcha fails (http://jcaptcha.sourceforge.net/) with similar behaviour makes me think that the issue is really with IE8. So my hope is more like "Is there a known workaround"? For example implementing my captcha response verification in a Servlet instead of a JSP page? Are there any options I can/should enable in my JSP page (for example, as to NOT "commit" the 'response' instance or so?)?

The following "live example" demonstrates the issue, at least with IE8 I could not Sign Up with the JCaptcha site (which is protected with their own implementation of JCaptcha ;) :

  http://forge.octo.com/jcaptcha/jira/secure/Signup!default.jspa

I did not find any "live example" on the net which uses SimpleCaptcha though.


Anyone else experienced issues with IE8 and SimpleCaptcha? Is it merely a question to "set some Internet Options" in IE, e.g. disable "Privaty Mode" (I don't think it is enabled in my case, I never changed any settings, and IE8 was installed automatically on my machine at home.


Thank you,
  Oliver
-- 
Oliver Knoll
Dipl. Informatik-Ing. ETH
COMIT AG - ++41 79 520 95 22