src/jdk.jlink/share/classes/jdk/tools/jlink/internal/plugins/IncludeLocalesPlugin.java

@@ -305,22 +305,26 @@
         return modified[0];
     }
 
     private boolean filterOutUnsupportedTags(byte[] b) {
         List<Locale> locales;
+        String original = new String(b);
 
         try {
-            locales = Arrays.asList(new String(b).split(" ")).stream()
+            locales = Arrays.asList(original.split(" ")).stream()
                 .filter(tag -> !tag.isEmpty())
                 .map(IncludeLocalesPlugin::tagToLocale)
                 .collect(Collectors.toList());
         } catch (IllformedLocaleException ile) {
             // Seems not an available locales string literal.
             return false;
         }
 
         byte[] filteredBytes = filterLocales(locales).stream()
+            // Make sure the filtered language tags do exist in the
+            // original supported tags for compatibility codes, e.g., "iw"
+            .filter(t -> original.indexOf(t) != -1)
             .collect(Collectors.joining(" "))
             .getBytes();
 
         if (filteredBytes.length > b.length) {
             throw new InternalError("Size of filtered locales is bigger than the original one");

@@ -329,10 +333,15 @@
         System.arraycopy(filteredBytes, 0, b, 0, filteredBytes.length);
         Arrays.fill(b, filteredBytes.length, b.length, (byte)' ');
         return true;
     }
 
+    /*
+     * Filter list of locales according to the secified priorityList. Note
+     * that returned list of language tags may include extra ones, such as
+     * compatibility ones (e.g., "iw" -> "iw", "he").
+     */
     private List<String> filterLocales(List<Locale> locales) {
         List<String> ret =
             Locale.filter(priorityList, locales, Locale.FilteringMode.EXTENDED_FILTERING).stream()
                 .flatMap(loc -> Stream.concat(Control.getNoFallbackControl(Control.FORMAT_DEFAULT)
                                      .getCandidateLocales("", loc).stream(),