Fix deprecated setting specializations

server/src/main/java/org/elasticsearch/common/settings/SecureSetting.java

@@ -69,7 +69,7 @@ public T getDefault(Settings settings) {
     }
 
     @Override
-    public String getRaw(Settings settings) {
+    String innerGetRaw(final Settings settings) {
         throw new UnsupportedOperationException("secure settings are not strings");
     }
 

server/src/main/java/org/elasticsearch/common/settings/Setting.java

@@ -426,8 +426,19 @@ public void diff(Settings.Builder builder, Settings source, Settings defaultSett
      * Returns the raw (string) settings value. If the setting is not present in the given settings object the default value is returned
      * instead. This is useful if the value can't be parsed due to an invalid value to access the actual value.
      */
-    public String getRaw(Settings settings) {
+    public final String getRaw(final Settings settings) {
         checkDeprecation(settings);
+        return innerGetRaw(settings);
+    }
+
+    /**
+     * The underlying implementation for {@link #getRaw(Settings)}. Setting specializations can override this as needed to convert the
+     * actual settings value to raw strings.
+     *
+     * @param settings the settings instance
+     * @return the raw string representation of the setting value
+     */
+    String innerGetRaw(final Settings settings) {
         return settings.get(getKey(), defaultValue.apply(settings));
     }
 
@@ -713,7 +724,7 @@ public T get(Settings settings) {
         }
 
         @Override
-        public String getRaw(Settings settings) {
+        public String innerGetRaw(final Settings settings) {
             throw new UnsupportedOperationException("affix settings can't return values" +
                 " use #getConcreteSetting to obtain a concrete setting");
         }
@@ -820,7 +831,7 @@ public boolean isGroupSetting() {
         }
 
         @Override
-        public String getRaw(Settings settings) {
+        public String innerGetRaw(final Settings settings) {
             Settings subSettings = get(settings);
             try {
                 XContentBuilder builder = XContentFactory.jsonBuilder();
@@ -913,7 +924,7 @@ private ListSetting(String key, Function<Settings, List<String>> defaultStringVa
         }
 
         @Override
-        public String getRaw(Settings settings) {
+        String innerGetRaw(final Settings settings) {
             List<String> array = settings.getAsList(getKey(), null);
             return array == null ? defaultValue.apply(settings) : arrayToParsableString(array);
         }

server/src/test/java/org/elasticsearch/common/settings/SettingTests.java

@@ -462,6 +462,26 @@ public void testCompositeValidator() {
 
     }
 
+    public void testListSettingsDeprecated() {
+        final Setting<List<String>> deprecatedListSetting =
+                Setting.listSetting(
+                        "foo.deprecated",
+                        Collections.singletonList("foo.deprecated"),
+                        Function.identity(),
+                        Property.Deprecated,
+                        Property.NodeScope);
+        final Setting<List<String>> nonDeprecatedListSetting =
+                Setting.listSetting(
+                        "foo.non_deprecated", Collections.singletonList("foo.non_deprecated"), Function.identity(), Property.NodeScope);
+        final Settings settings = Settings.builder()
+                .put("foo.deprecated", "foo.deprecated1,foo.deprecated2")
+                .put("foo.deprecated", "foo.non_deprecated1,foo.non_deprecated2")
+                .build();
+        deprecatedListSetting.get(settings);
+        nonDeprecatedListSetting.get(settings);
+        assertSettingDeprecationsAndWarnings(new Setting[]{deprecatedListSetting});
+    }
+
     public void testListSettings() {
         Setting<List<String>> listSetting = Setting.listSetting("foo.bar", Arrays.asList("foo,bar"), (s) -> s.toString(),
             Property.Dynamic, Property.NodeScope);