Bug 68011 [java search] "Search the JRE System Libraries" looks like a local preference but behaves as a global one... [search]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/FindAction.java
private void showOperationUnavailableDialog() {
		MessageDialog.openInformation(getShell(), SearchMessages.JavaElementAction_operationUnavailable_title, getOperationUnavailableMessage()); 
	}	
	String getOperationUnavailableMessage() {
		return SearchMessages.JavaElementAction_operationUnavailable_generic; 
	}
	private IJavaElement findType(ICompilationUnit cu, boolean silent) {
		IType[] types= null;
		try {					
			types= cu.getAllTypes();
		} catch (JavaModelException ex) {
			if (JavaModelUtil.isExceptionToBeLogged(ex))
				ExceptionHandler.log(ex, SearchMessages.JavaElementAction_error_open_message); 
			if (silent)
				return RETURN_WITHOUT_BEEP;
			else
				return null;
		}
		if (types.length == 1 || (silent && types.length > 0))
			return types[0];
		if (silent)
			return RETURN_WITHOUT_BEEP;
		if (types.length == 0)
			return null;
		String title= SearchMessages.JavaElementAction_typeSelectionDialog_title; 
		String message = SearchMessages.JavaElementAction_typeSelectionDialog_message; 
		int flags= (JavaElementLabelProvider.SHOW_DEFAULT);						
		ElementListSelectionDialog dialog= new ElementListSelectionDialog(getShell(), new JavaElementLabelProvider(flags));
		dialog.setTitle(title);
		dialog.setMessage(message);