Bug 45448 Operation unavailable attempting to search a local variable [search]
Build 20031023 Selecting a local variable declaration in a Java editor and attempting to search for references to this local variable brings up a dialog saying the the operation is unavailable for the selected element.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/FindAction.java
super(site);
		setText(label);
		fValidTypes= validTypes;
	}
	FindAction(JavaEditor editor, String label, Class[] validTypes) {
		this (editor.getEditorSite(), label, validTypes);
		fEditor= editor;
		setEnabled(SelectionConverter.canOperateOn(fEditor));
	}
	private boolean canOperateOn(IStructuredSelection sel) {
		return sel != null && !sel.isEmpty() && canOperateOn(getJavaElement(sel, true));
	}
		
	boolean canOperateOn(IJavaElement element) {
		if (fValidTypes == null || fValidTypes.length == 0)
			return false;
		if (element != null) {
			for (int i= 0; i < fValidTypes.length; i++) {
				if (fValidTypes[i].isInstance(element)) {
					if (element.getElementType() == IJavaElement.PACKAGE_FRAGMENT)
						return hasChildren((IPackageFragment)element);
					else
						return true;
				}
			}
		}
		return false;
	}
	
	private boolean hasChildren(IPackageFragment packageFragment) {