Index search freezes complete application

Question

We are using the JavaHelp for the context-sensitive online help functionality in an application. A very strange error occurred:
The index search works fine for many search strings, but for many other search string the complete application freezes. One of these strings is "ab" and strings starting with "ab". This is very annoying, because many german words start with the letter combination "ab". There are other strings which do not work, f.e. strings starting with "orts" and those which do work sometimes, like "ort".
When I am writing, "the application freezes", I mean that you can only stop it via the Windows Task Manager. Since you are loosing all data which had not been safed until searching the help index, the behaviour is not tolerable for our application.
We are working with the de_DE.UTF-8 German locale.
Looking at the threads, we noticed, that one thread was running the isStringInString method of class javax.help.HelpUtilities endlessly.
I found a bug report (6195811 "jdshelp freeze at search with l10n string") which seems to be related to this problem and in which is mentioned the following:
"On de_DE.UTF-8 German locale, the following strings cause freeze.
- <compose> + 'a' + ''' + b + <compose> + 'b' + '''"
This indicates that other people, too, must have the problem.
Now my questions:
Do you have any ideas for a workaround?
Do you know, if it is possible to disable the index search? And if it is possible: How can it be done?
By the way, does anyone know, when JavaHelp 2.0_03 will be published? The quoted bug is mentioned to be fixed in 2.0_03.
Thank you very much!
beap

Answer 1

Hi beap,
we are facing a similar problem. I filed bug report 6296005.
Do you use JRE 1.5? Our workaround is to use JRE 1.4.2, the bug does not occur with any JRE < 1.5.
When we detect that the user is running JRE 1.5, we just hide the Index tab. In our implementation of BasicHelpUI we do something like this:
     public void addNavigator(JHelpNavigator nav) {
        if(nav instanceof JHelpIndexNavigator) {
            final String java_version = System.getProperty("java.version");
            if (java_version.startsWith("1.5")){
                return;
        super.addNavigator(nav);
}It's an ugly hack but better than a customer who loses important data because our application freezes.
I will provide the help set to Sun so that they can further investigate and hopefully fix this bug.