Merge branch 'stable-3.3'

* stable-3.3:
  Update git submodules
  Bazel: Consume bazel-toolchains release from bazel mirror
  Align the recommended buildifier version with CI's
  crafting-changes: Add some info on Optional/Nullable
  Fix typo in event documentation section
  Bump bazel-toolchains to 5.0.0
  Set version to 2.16.28-SNAPSHOT
  Set version to 2.16.27
  ForRef#check should permit internal users to read all refs
  Fix NPE on trying to send email for user without email address
  Update git submodules
  Update highlightjs to 10.6.0
  Use NoteDb sequence seed for groups sequence initialization
  GroupsOnInit: Remove unused dependency on ReviewDb
  Use NoteDb sequence seed for accounts sequence initialization
  Do not use ReviewDb anymore when is disabled
  Elasticsearch: Discontinue EOL versions 7.2 and 7.3 support
  e2e-tests: Add SubmitChangeInBranch scenario
  Update developers based on gerritcodereview's list
  ForRef#check should permit internal users to read all refs

Change-Id: Id555d1b7b63d5cd0a27ff186be2931ff50dd442d
diff --git a/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java b/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
index e56f470..44a377a 100644
--- a/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
+++ b/java/com/google/gerrit/elasticsearch/AbstractElasticIndex.java
@@ -84,6 +84,9 @@
   protected static final String BULK = "_bulk";
   protected static final String MAPPINGS = "mappings";
   protected static final String ORDER = "order";
+  protected static final String DESC_SORT_ORDER = "desc";
+  protected static final String ASC_SORT_ORDER = "asc";
+  protected static final String UNMAPPED_TYPE = "unmapped_type";
   protected static final String SEARCH = "_search";
   protected static final String SETTINGS = "settings";
 
@@ -288,7 +291,7 @@
 
   protected JsonArray getSortArray(String idFieldName) {
     JsonObject properties = new JsonObject();
-    properties.addProperty(ORDER, "asc");
+    properties.addProperty(ORDER, ASC_SORT_ORDER);
 
     JsonArray sortArray = new JsonArray();
     addNamedElement(idFieldName, properties, sortArray);
diff --git a/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java b/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
index 625a598..969ffa5 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticChangeIndex.java
@@ -57,6 +57,9 @@
 import com.google.gson.JsonObject;
 import com.google.inject.Inject;
 import com.google.inject.assistedinject.Assisted;
+import java.sql.Timestamp;
+import java.time.Instant;
+import java.time.format.DateTimeFormatter;
 import java.util.Collections;
 import java.util.Optional;
 import java.util.Set;
@@ -133,14 +136,24 @@
 
   private JsonArray getSortArray() {
     JsonObject properties = new JsonObject();
-    properties.addProperty(ORDER, "desc");
+    properties.addProperty(ORDER, DESC_SORT_ORDER);
 
     JsonArray sortArray = new JsonArray();
     addNamedElement(ChangeField.UPDATED.getName(), properties, sortArray);
+    addNamedElement(ChangeField.MERGED_ON.getName(), getMergedOnSortOptions(), sortArray);
     addNamedElement(idField.getName(), properties, sortArray);
     return sortArray;
   }
 
+  private JsonObject getMergedOnSortOptions() {
+    JsonObject sortOptions = new JsonObject();
+    sortOptions.addProperty(ORDER, DESC_SORT_ORDER);
+    // Ignore the sort field if it does not exist in index. Otherwise the search would fail on open
+    // changes, because the corresponding documents do not have mergedOn field.
+    sortOptions.addProperty(UNMAPPED_TYPE, ElasticMapping.TIMESTAMP_FIELD_TYPE);
+    return sortOptions;
+  }
+
   @Override
   protected String getDeleteActions(Change.Id c) {
     return getDeleteRequest(c);
@@ -361,6 +374,10 @@
           cd);
     }
 
+    if (fields.contains(ChangeField.MERGED_ON.getName())) {
+      decodeMergedOn(source, cd);
+    }
+
     return cd;
   }
 
@@ -396,4 +413,18 @@
     }
     out.setUnresolvedCommentCount(count.getAsInt());
   }
+
+  private void decodeMergedOn(JsonObject doc, ChangeData out) {
+    JsonElement mergedOnField = doc.get(ChangeField.MERGED_ON.getName());
+
+    Timestamp mergedOn = null;
+    if (mergedOnField != null) {
+      // Parse from ElasticMapping.TIMESTAMP_FIELD_FORMAT.
+      // We currently use built-in ISO-based dateOptionalTime.
+      // https://www.elastic.co/guide/en/elasticsearch/reference/current/mapping-date-format.html#built-in-date-formats
+      DateTimeFormatter isoFormatter = DateTimeFormatter.ISO_INSTANT;
+      mergedOn = Timestamp.from(Instant.from(isoFormatter.parse(mergedOnField.getAsString())));
+    }
+    out.setMergedOn(mergedOn);
+  }
 }
diff --git a/java/com/google/gerrit/elasticsearch/ElasticConfiguration.java b/java/com/google/gerrit/elasticsearch/ElasticConfiguration.java
index 06b128c..c443529 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticConfiguration.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticConfiguration.java
@@ -26,8 +26,10 @@
 import java.net.URISyntaxException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 import org.apache.http.HttpHost;
 import org.eclipse.jgit.lib.Config;
+import org.elasticsearch.client.RestClientBuilder;
 
 @Singleton
 class ElasticConfiguration {
@@ -41,12 +43,16 @@
   static final String KEY_NUMBER_OF_SHARDS = "numberOfShards";
   static final String KEY_NUMBER_OF_REPLICAS = "numberOfReplicas";
   static final String KEY_MAX_RESULT_WINDOW = "maxResultWindow";
+  static final String KEY_CONNECT_TIMEOUT = "connectTimeout";
+  static final String KEY_SOCKET_TIMEOUT = "socketTimeout";
 
   static final String DEFAULT_PORT = "9200";
   static final String DEFAULT_USERNAME = "elastic";
   static final int DEFAULT_NUMBER_OF_SHARDS = 1;
   static final int DEFAULT_NUMBER_OF_REPLICAS = 1;
   static final int DEFAULT_MAX_RESULT_WINDOW = 10000;
+  static final int DEFAULT_CONNECT_TIMEOUT = RestClientBuilder.DEFAULT_CONNECT_TIMEOUT_MILLIS;
+  static final int DEFAULT_SOCKET_TIMEOUT = RestClientBuilder.DEFAULT_SOCKET_TIMEOUT_MILLIS;
 
   private final Config cfg;
   private final List<HttpHost> hosts;
@@ -56,6 +62,8 @@
   final int numberOfShards;
   final int numberOfReplicas;
   final int maxResultWindow;
+  final int connectTimeout;
+  final int socketTimeout;
   final String prefix;
 
   @Inject
@@ -74,6 +82,22 @@
         cfg.getInt(SECTION_ELASTICSEARCH, null, KEY_NUMBER_OF_REPLICAS, DEFAULT_NUMBER_OF_REPLICAS);
     this.maxResultWindow =
         cfg.getInt(SECTION_ELASTICSEARCH, null, KEY_MAX_RESULT_WINDOW, DEFAULT_MAX_RESULT_WINDOW);
+    this.connectTimeout =
+        (int)
+            cfg.getTimeUnit(
+                SECTION_ELASTICSEARCH,
+                null,
+                KEY_CONNECT_TIMEOUT,
+                DEFAULT_CONNECT_TIMEOUT,
+                TimeUnit.MILLISECONDS);
+    this.socketTimeout =
+        (int)
+            cfg.getTimeUnit(
+                SECTION_ELASTICSEARCH,
+                null,
+                KEY_SOCKET_TIMEOUT,
+                DEFAULT_SOCKET_TIMEOUT,
+                TimeUnit.MILLISECONDS);
     this.hosts = new ArrayList<>();
     for (String server : cfg.getStringList(SECTION_ELASTICSEARCH, null, KEY_SERVER)) {
       try {
diff --git a/java/com/google/gerrit/elasticsearch/ElasticMapping.java b/java/com/google/gerrit/elasticsearch/ElasticMapping.java
index f8c4168..edd05c9 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticMapping.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticMapping.java
@@ -21,6 +21,10 @@
 import java.util.Map;
 
 class ElasticMapping {
+
+  protected static final String TIMESTAMP_FIELD_TYPE = "date";
+  protected static final String TIMESTAMP_FIELD_FORMAT = "dateOptionalTime";
+
   static MappingProperties createMapping(Schema<?> schema, ElasticQueryAdapter adapter) {
     ElasticMapping.Builder mapping = new ElasticMapping.Builder(adapter);
     for (FieldDef<?, ?> field : schema.getFields().values()) {
@@ -71,9 +75,9 @@
     }
 
     Builder addTimestamp(String name) {
-      FieldProperties properties = new FieldProperties("date");
-      properties.type = "date";
-      properties.format = "dateOptionalTime";
+      FieldProperties properties = new FieldProperties(TIMESTAMP_FIELD_TYPE);
+      properties.type = TIMESTAMP_FIELD_TYPE;
+      properties.format = TIMESTAMP_FIELD_FORMAT;
       fields.put(name, properties);
       return this;
     }
diff --git a/java/com/google/gerrit/elasticsearch/ElasticQueryBuilder.java b/java/com/google/gerrit/elasticsearch/ElasticQueryBuilder.java
index d05e91c..40ac603 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticQueryBuilder.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticQueryBuilder.java
@@ -29,7 +29,6 @@
 import com.google.gerrit.index.query.QueryParseException;
 import com.google.gerrit.index.query.RegexPredicate;
 import com.google.gerrit.index.query.TimestampRangePredicate;
-import com.google.gerrit.server.query.change.AfterPredicate;
 import java.time.Instant;
 
 public class ElasticQueryBuilder {
@@ -130,7 +129,9 @@
   private <T> QueryBuilder timestampQuery(IndexPredicate<T> p) throws QueryParseException {
     if (p instanceof TimestampRangePredicate) {
       TimestampRangePredicate<T> r = (TimestampRangePredicate<T>) p;
-      if (p instanceof AfterPredicate) {
+      if (r.getMaxTimestamp().getTime() == Long.MAX_VALUE) {
+        // The time range only has the start value, search from the start to the max supported value
+        // Long.MAX_VALUE
         return QueryBuilders.rangeQuery(r.getField().getName())
             .gte(Instant.ofEpochMilli(r.getMinTimestamp().getTime()));
       }
diff --git a/java/com/google/gerrit/elasticsearch/ElasticRestClientProvider.java b/java/com/google/gerrit/elasticsearch/ElasticRestClientProvider.java
index f635b23..b41f365 100644
--- a/java/com/google/gerrit/elasticsearch/ElasticRestClientProvider.java
+++ b/java/com/google/gerrit/elasticsearch/ElasticRestClientProvider.java
@@ -27,6 +27,7 @@
 import org.apache.http.auth.AuthScope;
 import org.apache.http.auth.UsernamePasswordCredentials;
 import org.apache.http.client.CredentialsProvider;
+import org.apache.http.client.config.RequestConfig;
 import org.apache.http.impl.client.BasicCredentialsProvider;
 import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
 import org.elasticsearch.client.Request;
@@ -128,10 +129,19 @@
 
   private RestClient build() {
     RestClientBuilder builder = RestClient.builder(cfg.getHosts());
+    setConfiguredTimeouts(builder);
     setConfiguredCredentialsIfAny(builder);
     return builder.build();
   }
 
+  private void setConfiguredTimeouts(RestClientBuilder builder) {
+    builder.setRequestConfigCallback(
+        (RequestConfig.Builder requestConfigBuilder) ->
+            requestConfigBuilder
+                .setConnectTimeout(cfg.connectTimeout)
+                .setSocketTimeout(cfg.socketTimeout));
+  }
+
   private void setConfiguredCredentialsIfAny(RestClientBuilder builder) {
     String username = cfg.username;
     String password = cfg.password;