Bug 30630 nested source folders: unclear error message
20030129 create a jproject, a source folder s1 and a nested in it source folder s2 delete s1 open the 'new' wizard and try creating a source folder s1 the error message is very long and compilicated while it should be a simple warning saying 'You have a folder s1 - I will turn it into a source folder fo you' (and then it could automagically add excelusion filter so that s2 is still a source folder)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/SourceContainerWorkbookPage.java
if (elem instanceof CPListElementAttribute) {
				CPListElementAttribute attrib= (CPListElementAttribute) elem;
				if (attrib.getKey().equals(CPListElement.EXCLUSION)) {
					if (((IPath[]) attrib.getValue()).length == 0) {
						return false;
					}
				} else if (attrib.getValue() == null) {
					return false;
				}
			} else if (elem instanceof CPListElement) {
				CPListElement curr= (CPListElement) elem;
				if (curr.getParentContainer() != null) {
					return false;
				}
			}
		}
		return true;
	}		
	
	private boolean canEdit(List selElements) {
		if (selElements.size() != 1) {
			return false;
		}
		Object elem= selElements.get(0);
		if (fFoldersList.getIndexOfElement(elem) != -1) {
			return true;
		}
		if (elem instanceof CPListElementAttribute) {
			return true;
		}