can't open library source of second class in file

Bas Leijdekkers wrote:

This gets the source of java.awt.Container:

 final PsiManager manager = PsiManager.getInstance(project);
> final GlobalSearchScope globalScope = GlobalSearchScope.allScope(project);
> 
> final String source = manager.findClass("java.awt.Container", globalScope).getNavigationElement().getText();
> ]]>

This just gets the decompiled class file of java.awt.LightweightDispatcher:

 final String source = manager.findClass("java.awt.LightweightDispatcher", globalScope).getNavigationElement().getText();
> ]]>

However both are contained in the same source file! How do I get to the source of java.awt.LightweightDispatcher? Is this a bug?

Strange, I can't even open the source using ctrl+n. It only happens
using one jdk and deleting the caches doesn't help.

Bas