src/jdk.scripting.nashorn.shell/share/classes/jdk/nashorn/tools/jjs/EditObject.java

*** 84,94 ****
      }
  
      @Override
      public void setMember(final String name, final Object value) {
          if (name.equals("editor")) {
!             this.editor = JSType.toString(value);
          }
      }
  
      // called whenever user 'saves' script in editor
      class SaveHandler implements Consumer<String> {
--- 84,94 ----
      }
  
      @Override
      public void setMember(final String name, final Object value) {
          if (name.equals("editor")) {
!             this.editor = value != null && value != UNDEFINED? JSType.toString(value) : "";
          }
      }
  
      // called whenever user 'saves' script in editor
      class SaveHandler implements Consumer<String> {
*** 113,124 ****
      public Object call(final Object thiz, final Object... args) {
          final String initText = args.length > 0? JSType.toString(args[0]) : "";
          final SaveHandler saveHandler = new SaveHandler(initText);
          if (editor != null && !editor.isEmpty()) {
              ExternalEditor.edit(editor, errorHandler, initText, saveHandler, console);
!         } else {
              EditPad.edit(errorHandler, initText, saveHandler);
          }
          return UNDEFINED;
      }
  
      @Override
--- 113,126 ----
      public Object call(final Object thiz, final Object... args) {
          final String initText = args.length > 0? JSType.toString(args[0]) : "";
          final SaveHandler saveHandler = new SaveHandler(initText);
          if (editor != null && !editor.isEmpty()) {
              ExternalEditor.edit(editor, errorHandler, initText, saveHandler, console);
!         } else if (! Main.HEADLESS) {
              EditPad.edit(errorHandler, initText, saveHandler);
+         } else {
+             errorHandler.accept(Main.getMessage("no.editor"));
          }
          return UNDEFINED;
      }
  
      @Override