src/java.desktop/macosx/classes/com/apple/laf/AquaComboBoxRendererInternal.java

*** 1,7 ****
  /*
!  * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 2013, 2019, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 50,60 ****
      public Dimension getPreferredSize() {
          // From BasicComboBoxRenderer - trick to avoid zero-height items
          final Dimension size;
  
          final String text = getText();
!         if ((text == null) || ("".equals(text))) {
              setText(" ");
              size = super.getPreferredSize();
              setText("");
          } else {
              size = super.getPreferredSize();
--- 50,60 ----
      public Dimension getPreferredSize() {
          // From BasicComboBoxRenderer - trick to avoid zero-height items
          final Dimension size;
  
          final String text = getText();
!         if (text == null || text.isEmpty()) {
              setText(" ");
              size = super.getPreferredSize();
              setText("");
          } else {
              size = super.getPreferredSize();