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core/src/main/java/org/elasticsearch/gateway/TransportNodesListGatewayStartedShards.java

@@ -131,7 +131,7 @@ public class TransportNodesListGatewayStartedShards extends TransportNodesAction
                 if (metaData != null) {
                     ShardPath shardPath = null;
                     try {
-                        IndexSettings indexSettings = new IndexSettings(new Index(metaData.getIndex()), Settings.settingsBuilder().put(settings).put(metaData.getSettings()).build(), Collections.EMPTY_LIST);
+                        IndexSettings indexSettings = new IndexSettings(shardId.index(), Settings.settingsBuilder().put(settings).put(metaData.getSettings()).build(), Collections.EMPTY_LIST);
                         shardPath = ShardPath.loadShardPath(logger, nodeEnv, shardId, indexSettings);
                         if (shardPath == null) {
                             throw new IllegalStateException(shardId + " no shard path found");

core/src/main/java/org/elasticsearch/index/IndexModule.java

@@ -90,7 +90,7 @@ public class IndexModule extends AbstractModule {
      * Note: an index might be created on a node multiple times. For instance if the last shard from an index is
      * relocated to another node the internal representation will be destroyed which includes the registered listeners.
      * Once the node holds at least one shard of an index all modules are reloaded and listeners are registered again.
-     * Listeners can't be unregistered the will stay alive for the entire time the index is allocated on a node.
+     * Listeners can't be unregistered they will stay alive for the entire time the index is allocated on a node.
      * </p>
      */
     public void addIndexEventListener(IndexEventListener listener) {

core/src/main/java/org/elasticsearch/index/IndexService.java

@@ -57,7 +57,6 @@ import java.nio.file.Path;
 import java.util.*;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.function.Consumer;
 
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.unmodifiableMap;
@@ -509,7 +508,7 @@ public class IndexService extends AbstractIndexComponent implements IndexCompone
     public synchronized void updateMetaData(final IndexMetaData metadata) {
         this.indexMetaData = metadata;
         Settings settings = metadata.getSettings();
-        if (this.indexSettings.updateSettings(metadata.getSettings())) {
+        if (this.indexSettings.updateIndexSettings(metadata.getSettings())) {
             for (final IndexShard shard : this.shards.values()) {
                 try {
                     shard.onRefreshSettings(settings);

core/src/main/java/org/elasticsearch/index/IndexSettings.java

@@ -112,25 +112,26 @@ public final class IndexSettings {
      *
      * @return <code>true</code> iff any setting has been updated otherwise <code>false</code>.
      */
-    synchronized boolean updateSettings(Settings settings) {
+    synchronized boolean updateIndexSettings(Settings newSettings) {
-        if (Version.indexCreated(settings) != version) {
+        if (Version.indexCreated(newSettings) != version) {
-            throw new IllegalArgumentException("version mismatch on settings update expected: " + version + " but was: " + Version.indexCreated(settings));
+            throw new IllegalArgumentException("version mismatch on settings update expected: " + version + " but was: " + Version.indexCreated(newSettings));
         }
-        final String newUUID = settings.get(IndexMetaData.SETTING_INDEX_UUID, IndexMetaData.INDEX_UUID_NA_VALUE);
+        final String newUUID = newSettings.get(IndexMetaData.SETTING_INDEX_UUID, IndexMetaData.INDEX_UUID_NA_VALUE);
         if (newUUID.equals(getUUID()) == false) {
             throw new IllegalArgumentException("uuid mismatch on settings update expected: " + uuid + " but was: " + newUUID);
         }
-
+        final Settings existingSettings = this.settings;
-        if (this.settings.getByPrefix(IndexMetaData.INDEX_SETTING_PREFIX).getAsMap().equals(settings.getByPrefix(IndexMetaData.INDEX_SETTING_PREFIX).getAsMap())) {
+        if (existingSettings.getByPrefix(IndexMetaData.INDEX_SETTING_PREFIX).getAsMap().equals(newSettings.getByPrefix(IndexMetaData.INDEX_SETTING_PREFIX).getAsMap())) {
             // nothing to update, same settings
             return false;
         }
-        this.settings = Settings.builder().put(this.settings).put(settings).build();
+        this.settings = Settings.builder().put(existingSettings).put(newSettings).build();
+        final Settings mergedSettings = this.settings;
         for (final Consumer<Settings> consumer : updateListeners) {
             try {
-                consumer.accept(settings);
+                consumer.accept(mergedSettings);
             } catch (Exception e) {
-                logger.warn("failed to refresh index settings for [{}]", e, settings);
+                logger.warn("failed to refresh index settings for [{}]", e, mergedSettings);
             }
         }
         return true;

core/src/test/java/org/elasticsearch/index/IndexSettingsTests.java

@@ -42,13 +42,36 @@ public class IndexSettingsTests extends ESTestCase {
         assertEquals("0xdeadbeef", settings.getUUID());
 
         assertEquals(1, settings.getUpdateListeners().size());
-        assertFalse(settings.updateSettings(theSettings));
+        assertFalse(settings.updateIndexSettings(theSettings));
         assertSame(theSettings, settings.getSettings());
         assertEquals(0, integer.get());
-        assertTrue(settings.updateSettings(Settings.builder().put(theSettings).put("index.test.setting.int", 42).build()));
+        assertTrue(settings.updateIndexSettings(Settings.builder().put(theSettings).put("index.test.setting.int", 42).build()));
         assertEquals(42, integer.get());
     }
 
+    public void testMergedSettingsArePassed() {
+        Version version = VersionUtils.getPreviousVersion();
+        Settings theSettings = Settings.settingsBuilder().put(IndexMetaData.SETTING_VERSION_CREATED, version)
+                .put(IndexMetaData.SETTING_INDEX_UUID, "0xdeadbeef").build();
+        final AtomicInteger integer = new AtomicInteger(0);
+        final StringBuilder builder = new StringBuilder();
+        Consumer<Settings> settingsConsumer = (s) -> {
+            integer.set(s.getAsInt("index.test.setting.int", -1));
+            builder.append(s.get("not.updated", ""));
+        };
+        IndexSettings settings = new IndexSettings(new Index("index"), theSettings, Collections.singleton(settingsConsumer));
+        assertEquals(0, integer.get());
+        assertEquals("", builder.toString());
+        assertTrue(settings.updateIndexSettings(Settings.builder().put(theSettings).put("index.test.setting.int", 42).build()));
+        assertEquals(42, integer.get());
+        assertEquals("", builder.toString());
+        integer.set(0);
+        assertTrue(settings.updateIndexSettings(Settings.builder().put(theSettings).put("not.updated", "boom").build()));
+        assertEquals("boom", builder.toString());
+        assertEquals(42, integer.get());
+
+    }
+
     public void testListenerCanThrowException() {
         Version version = VersionUtils.getPreviousVersion();
         Settings theSettings = Settings.settingsBuilder().put(IndexMetaData.SETTING_VERSION_CREATED, version).put(IndexMetaData.SETTING_INDEX_UUID, "0xdeadbeef").build();
@@ -61,7 +84,7 @@ public class IndexSettingsTests extends ESTestCase {
         Collections.shuffle(list, random());
         IndexSettings settings = new IndexSettings(new Index("index"), theSettings, list);
         assertEquals(0, integer.get());
-        assertTrue(settings.updateSettings(Settings.builder().put(theSettings).put("index.test.setting.int", 42).build()));
+        assertTrue(settings.updateIndexSettings(Settings.builder().put(theSettings).put("index.test.setting.int", 42).build()));
         assertEquals(42, integer.get());
     }
 
@@ -72,7 +95,7 @@ public class IndexSettingsTests extends ESTestCase {
         assertEquals(version, settings.getIndexVersionCreated());
         assertEquals("_na_", settings.getUUID());
         try {
-            settings.updateSettings(Settings.builder().put(IndexMetaData.SETTING_VERSION_CREATED, Version.CURRENT).put("index.test.setting.int", 42).build());
+            settings.updateIndexSettings(Settings.builder().put(IndexMetaData.SETTING_VERSION_CREATED, Version.CURRENT).put("index.test.setting.int", 42).build());
             fail("version has changed");
         } catch (IllegalArgumentException ex) {
             assertTrue(ex.getMessage(), ex.getMessage().startsWith("version mismatch on settings update expected: "));
@@ -81,7 +104,7 @@ public class IndexSettingsTests extends ESTestCase {
         theSettings = Settings.settingsBuilder().put(IndexMetaData.SETTING_VERSION_CREATED, Version.CURRENT).put(IndexMetaData.SETTING_INDEX_UUID, "0xdeadbeef").build();
         settings = new IndexSettings(new Index("index"), theSettings, Collections.EMPTY_LIST);
         try {
-            settings.updateSettings(Settings.builder().put(IndexMetaData.SETTING_VERSION_CREATED, Version.CURRENT).put("index.test.setting.int", 42).build());
+            settings.updateIndexSettings(Settings.builder().put(IndexMetaData.SETTING_VERSION_CREATED, Version.CURRENT).put("index.test.setting.int", 42).build());
             fail("uuid missing/change");
         } catch (IllegalArgumentException ex) {
             assertEquals("uuid mismatch on settings update expected: 0xdeadbeef but was: _na_", ex.getMessage());