Functionality to append new value to an existing registry value causes registry value to grow

There has been introduced a new functionality into the registry manipulation functionality tracked by issue IZPACK-112. This functionality allows it to append a new value to an existing registry value. This may be used to extend the windows PATH variable. This works fine as long the user is not installing the application over an existing installation without previously uninstalling it. In this case the Windows PATH variable is growing for each installation and contains duplicate entries.

I made a change to Win_RegistryHandler.java to search for existing entries in the given registry value if the $OLD_KEY_VALUE variable is given and do only appending the new value if it is not already there Currently this fix works really well but there are some drawbacks for the application design.

Design Issue:

• This change is specific for manipulating Windows PATH variable structures placed in a class and function (Win_RegistryHandler.setValue()) doing general registry string value manipulation .

Functionality Issue:

• This change will change the previous behavior and the user is not able to configure if it shall replace existing values or if it shall just append the given value. Maybe another attribute is needed to give control about it to the user in the registry spec.