Bug 13034 Cannot create a Source Folder in a new Java Project
build 20020404 If you try and create a Source Folder in a Java Project you have just created you get an error preventing you from hitting finish. STEPS 1) Create Java Project Foo 2) Open New->Source Folder 3) Enter Bar as the name - you will get "Cannot nest entry Bar inside entry Foo/Bar" 4) Create a folder Bar. 5) Add it as a source folder in the Properties Dialog for Foo. No problem.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/BuildPathsBlock.java
ElementTreeSelectionDialog dialog= new ElementTreeSelectionDialog(getShell(), lp, cp);
		dialog.setTitle(NewWizardMessages.getString("BuildPathsBlock.ChooseOutputFolderDialog.title")); 
		dialog.setValidator(validator);
		dialog.setMessage(NewWizardMessages.getString("BuildPathsBlock.ChooseOutputFolderDialog.description")); 
		dialog.addFilter(filter);
		dialog.setInput(fWorkspaceRoot);
		dialog.setInitialSelection(initSelection);
		
		if (dialog.open() == dialog.OK) {
			return (IContainer)dialog.getFirstResult();
		}
		return null;
	}
	
	
	
	private void tabChanged(Widget widget) {
		if (widget instanceof TabItem) {
			BuildPathBasePage newPage= (BuildPathBasePage) ((TabItem) widget).getData();
			if (fCurrPage != null) {
				List selection= fCurrPage.getSelection();
				if (!selection.isEmpty()) {
					newPage.setSelection(selection);
				}
			}
			fCurrPage= newPage;
		}
	}		
}