I am not sure, please correct me if I am wrong, but it seems that this only works if the source is provided. On many applications the source is simply not available. When doing the intellisense popups the javadocs are shown for JARs that have a JavaDoc API URL/location specified but who do not have any source specified.
If we can get the JavaDocs for this can we not take the JavaDocs from these supplied URI/locations and use them when copying the JavaDoc for function override stuff?
If this is supposed to work right now I have never been able to get it to work correctly. If my message isn't clear please let me know.