--- old/src/jdk.incubator.jpackage/macosx/classes/jdk/incubator/jpackage/internal/MacAppImageBuilder.java	2020-02-26 17:47:28.305674200 -0500
+++ new/src/jdk.incubator.jpackage/macosx/classes/jdk/incubator/jpackage/internal/MacAppImageBuilder.java	2020-02-26 17:47:25.622419400 -0500
@@ -111,7 +111,15 @@
                             return identifier;
                         }
 
-                        return IDENTIFIER.fetchFrom(params);
+                        identifier = IDENTIFIER.fetchFrom(params);
+                        if (identifier != null) {
+                            return identifier;
+                        }
+                        // the IDENTIFIER (above) will default to derive from
+                        // the main-class, in case there is no main-class
+                        // (such as runtime installer) revert to the name.
+                        // any of these could be invalid, so check later.
+                        return APP_NAME.fetchFrom(params);
                     },
                     (s, p) -> s);
 
--- old/src/jdk.incubator.jpackage/macosx/classes/jdk/incubator/jpackage/internal/MacPkgBundler.java	2020-02-26 17:47:47.693426000 -0500
+++ new/src/jdk.incubator.jpackage/macosx/classes/jdk/incubator/jpackage/internal/MacPkgBundler.java	2020-02-26 17:47:45.252803900 -0500
@@ -510,22 +510,43 @@
         return "pkg";
     }
 
+    private static boolean isValidBundleIdentifier(String id) {
+        for (int i = 0; i < id.length(); i++) {
+            char a = id.charAt(i);
+            // We check for ASCII codes first which we accept. If check fails,
+            // check if it is acceptable extended ASCII or unicode character.
+            if ((a >= 'A' && a <= 'Z') || (a >= 'a' && a <= 'z')
+                    || (a >= '0' && a <= '9') || (a == '-' || a == '.')) {
+                continue;
+            }
+            return false;
+        }
+        return true;
+    }
+
     @Override
     public boolean validate(Map<String, ? super Object> params)
             throws ConfigException {
         try {
             Objects.requireNonNull(params);
 
-            // run basic validation to ensure requirements are met
+            // run basic validation to ensure requirements are met 
             // we are not interested in return code, only possible exception
             validateAppImageAndBundeler(params);
 
-            if (MAC_CF_BUNDLE_IDENTIFIER.fetchFrom(params) == null) {
+            String identifier = MAC_CF_BUNDLE_IDENTIFIER.fetchFrom(params);
+            if (identifier == null) {
                 throw new ConfigException(
                         I18N.getString("message.app-image-requires-identifier"),
                         I18N.getString(
                             "message.app-image-requires-identifier.advice"));
             }
+            if (!isValidBundleIdentifier(identifier)) {
+                throw new ConfigException(
+                        MessageFormat.format(I18N.getString(
+                        "message.invalid-identifier"), identifier),
+                        I18N.getString("message.invalid-identifier.advice"));
+            }
 
             // reject explicitly set sign to true and no valid signature key
             if (Optional.ofNullable(MacAppImageBuilder.
--- old/src/jdk.incubator.jpackage/macosx/classes/jdk/incubator/jpackage/internal/resources/MacResources.properties	2020-02-26 17:48:04.379839700 -0500
+++ new/src/jdk.incubator.jpackage/macosx/classes/jdk/incubator/jpackage/internal/resources/MacResources.properties	2020-02-26 17:48:02.312837200 -0500
@@ -76,6 +76,8 @@
 message.app-image-requires-app-name.advice=Set the app name via the -name CLI flag, the fx:application/@name ANT attribute, or via the 'appName' bundler argument.
 message.app-image-requires-identifier=Unable to extract identifier from app image.
 message.app-image-requires-identifier.advice=Use "--verbose" for extended error message or specify it via "--mac-package-identifier".
+message.invalid-identifier=invalid mac bundle identifier [{0}].
+message.invalid-identifier.advice=specify identifier with "--mac-package-identifier".
 message.building-dmg=Building DMG package for {0}.
 message.running-script=Running shell script on application image [{0}].
 message.preparing-dmg-setup=Preparing dmg setup: {0}.