Index: src/main/java/common/javax/swing/JEditorPane.java =================================================================== --- src/main/java/common/javax/swing/JEditorPane.java (revision 496662) +++ src/main/java/common/javax/swing/JEditorPane.java (working copy) @@ -248,6 +248,10 @@ } public static String getEditorKitClassNameForContentType(final String type) { + if (type == null) { + throw new NullPointerException(); + } + int index = contentTypes.indexOf(type); return (index >= 0) ? editorKitNames.get(index) : null; }