Merge changes from topic 'notedb-accounts-1'

* changes:
  AccountsUpdate: Rename atomicUpdate to update
  AccountsUpdate: Rename update method to replace
  Always update accounts atomically
  Migrate accounts to NoteDb (part 2)
  Disallow updates to account.config by direct push or submit
  Migrate accounts to NoteDb (part 1)
  Let AccountsUpdate#insert create the Account instance
  AccountsUpdate: Remove upsert method

gerrit-acceptance-framework/src/test/java/com/google/gerrit/acceptance/AccountCreator.java

@@ -19,7 +19,6 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import static java.nio.charset.StandardCharsets.US_ASCII;
 
 import com.google.gerrit.common.Nullable;
-import com.google.gerrit.common.TimeUtil;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.AccountGroup;
 import com.google.gerrit.reviewdb.client.AccountGroupMember;
@@ -109,10 +108,15 @@ public class AccountCreator {
       }
       externalIdsUpdate.create().insert(extIds);
 
-      Account a = new Account(id, TimeUtil.nowTs());
-      a.setFullName(fullName);
-      a.setPreferredEmail(email);
-      accountsUpdate.create().insert(db, a);
+      accountsUpdate
+          .create()
+          .insert(
+              db,
+              id,
+              a -> {
+                a.setFullName(fullName);
+                a.setPreferredEmail(email);
+              });
 
       if (groups != null) {
         for (String n : groups) {

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/accounts/AccountIT.java

@@ -32,6 +32,7 @@ import static com.google.gerrit.server.group.SystemGroupBackend.ANONYMOUS_USERS;
 import static com.google.gerrit.server.group.SystemGroupBackend.REGISTERED_USERS;
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.util.stream.Collectors.toSet;
+import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
 import static org.junit.Assert.fail;
 
 import com.google.common.collect.FluentIterable;
@@ -74,6 +75,7 @@ import com.google.gerrit.gpg.testutil.TestKey;
 import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.RefNames;
 import com.google.gerrit.server.account.AccountByEmailCache;
+import com.google.gerrit.server.account.AccountConfig;
 import com.google.gerrit.server.account.WatchConfig;
 import com.google.gerrit.server.account.WatchConfig.NotifyType;
 import com.google.gerrit.server.account.externalids.ExternalId;
@@ -91,7 +93,6 @@ import com.google.inject.Provider;
 import java.io.ByteArrayOutputStream;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collection;
 import java.util.EnumSet;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -106,6 +107,7 @@ import org.eclipse.jgit.api.errors.TransportException;
 import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
 import org.eclipse.jgit.junit.TestRepository;
 import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.Repository;
@@ -114,6 +116,7 @@ import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.transport.PushCertificateIdent;
 import org.eclipse.jgit.transport.PushResult;
 import org.eclipse.jgit.transport.RemoteRefUpdate;
+import org.eclipse.jgit.treewalk.TreeWalk;
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
@@ -162,8 +165,8 @@ public class AccountIT extends AbstractDaemonTest {
     externalIdsUpdate = externalIdsUpdateFactory.create();
 
     savedExternalIds = new ArrayList<>();
-    savedExternalIds.addAll(getExternalIds(admin));
-    savedExternalIds.addAll(getExternalIds(user));
+    savedExternalIds.addAll(externalIds.byAccount(admin.id));
+    savedExternalIds.addAll(externalIds.byAccount(user.id));
   }
 
   @After
@@ -172,8 +175,8 @@ public class AccountIT extends AbstractDaemonTest {
       // savedExternalIds is null when we don't run SSH tests and the assume in
       // @Before in AbstractDaemonTest prevents this class' @Before method from
       // being executed.
-      externalIdsUpdate.delete(getExternalIds(admin));
-      externalIdsUpdate.delete(getExternalIds(user));
+      externalIdsUpdate.delete(externalIds.byAccount(admin.id));
+      externalIdsUpdate.delete(externalIds.byAccount(user.id));
       externalIdsUpdate.insert(savedExternalIds);
     }
   }
@@ -190,10 +193,6 @@ public class AccountIT extends AbstractDaemonTest {
     }
   }
 
-  private Collection<ExternalId> getExternalIds(TestAccount account) throws Exception {
-    return accountCache.get(account.getId()).getExternalIds();
-  }
-
   @After
   public void deleteGpgKeys() throws Exception {
     String ref = REFS_GPG_KEYS;
@@ -220,6 +219,67 @@ public class AccountIT extends AbstractDaemonTest {
     create(3); // account creation + external ID creation + adding SSH keys
   }
 
+  private void create(int expectedAccountReindexCalls) throws Exception {
+    String name = "foo";
+    TestAccount foo = accountCreator.create(name);
+    AccountInfo info = gApi.accounts().id(foo.id.get()).get();
+    assertThat(info.username).isEqualTo(name);
+    assertThat(info.name).isEqualTo(name);
+    accountIndexedCounter.assertReindexOf(foo, expectedAccountReindexCalls);
+
+    // check user branch
+    try (Repository repo = repoManager.openRepository(allUsers);
+        RevWalk rw = new RevWalk(repo);
+        ObjectReader or = repo.newObjectReader()) {
+      Ref ref = repo.exactRef(RefNames.refsUsers(foo.getId()));
+      assertThat(ref).isNotNull();
+      RevCommit c = rw.parseCommit(ref.getObjectId());
+      long timestampDiffMs =
+          Math.abs(
+              c.getCommitTime() * 1000L
+                  - accountCache.get(foo.getId()).getAccount().getRegisteredOn().getTime());
+      assertThat(timestampDiffMs).isAtMost(ChangeRebuilderImpl.MAX_WINDOW_MS);
+
+      // Check the 'account.config' file.
+      try (TreeWalk tw = TreeWalk.forPath(or, AccountConfig.ACCOUNT_CONFIG, c.getTree())) {
+        assertThat(tw).isNotNull();
+        Config cfg = new Config();
+        cfg.fromText(new String(or.open(tw.getObjectId(0), OBJ_BLOB).getBytes(), UTF_8));
+        assertThat(cfg.getString(AccountConfig.ACCOUNT, null, AccountConfig.KEY_FULL_NAME))
+            .isEqualTo(name);
+      }
+    }
+  }
+
+  @Test
+  public void createAnonymousCoward() throws Exception {
+    TestAccount anonymousCoward = accountCreator.create();
+    accountIndexedCounter.assertReindexOf(anonymousCoward);
+
+    // check user branch
+    try (Repository repo = repoManager.openRepository(allUsers);
+        RevWalk rw = new RevWalk(repo);
+        ObjectReader or = repo.newObjectReader()) {
+      Ref ref = repo.exactRef(RefNames.refsUsers(anonymousCoward.getId()));
+      assertThat(ref).isNotNull();
+      RevCommit c = rw.parseCommit(ref.getObjectId());
+      long timestampDiffMs =
+          Math.abs(
+              c.getCommitTime() * 1000L
+                  - accountCache
+                      .get(anonymousCoward.getId())
+                      .getAccount()
+                      .getRegisteredOn()
+                      .getTime());
+      assertThat(timestampDiffMs).isAtMost(ChangeRebuilderImpl.MAX_WINDOW_MS);
+
+      // No account properties were set, hence an 'account.config' file was not created.
+      try (TreeWalk tw = TreeWalk.forPath(or, AccountConfig.ACCOUNT_CONFIG, c.getTree())) {
+        assertThat(tw).isNull();
+      }
+    }
+  }
+
   @Test
   public void get() throws Exception {
     AccountInfo info = gApi.accounts().id("admin").get();
@@ -693,6 +753,36 @@ public class AccountIT extends AbstractDaemonTest {
     accountIndexedCounter.assertReindexOf(admin);
   }
 
+  @Test
+  public void pushAccountConfigToUserBranchForReviewIsRejectedOnSubmit() throws Exception {
+    String userRefName = RefNames.refsUsers(admin.id);
+    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+    fetch(allUsersRepo, userRefName + ":userRef");
+    allUsersRepo.reset("userRef");
+
+    Config ac = getAccountConfig(allUsersRepo);
+    ac.setString(AccountConfig.ACCOUNT, null, AccountConfig.KEY_STATUS, "OOO");
+
+    PushOneCommit.Result r =
+        pushFactory
+            .create(
+                db,
+                admin.getIdent(),
+                allUsersRepo,
+                "Update account config",
+                AccountConfig.ACCOUNT_CONFIG,
+                ac.toText())
+            .to(MagicBranch.NEW_CHANGE + userRefName);
+    r.assertOkStatus();
+    accountIndexedCounter.assertNoReindex();
+    assertThat(r.getChange().change().getDest().get()).isEqualTo(userRefName);
+    gApi.changes().id(r.getChangeId()).current().review(ReviewInput.approve());
+    exception.expect(ResourceConflictException.class);
+    exception.expectMessage(
+        String.format("update of %s not allowed", AccountConfig.ACCOUNT_CONFIG));
+    gApi.changes().id(r.getChangeId()).current().submit();
+  }
+
   @Test
   public void pushWatchConfigToUserBranch() throws Exception {
     TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
@@ -734,6 +824,28 @@ public class AccountIT extends AbstractDaemonTest {
             WatchConfig.WATCH_CONFIG, admin.getId().get(), project.get(), invalidNotifyValue));
   }
 
+  @Test
+  public void pushAccountConfigToUserBranchIsRejected() throws Exception {
+    TestRepository<InMemoryRepository> allUsersRepo = cloneProject(allUsers);
+    fetch(allUsersRepo, RefNames.refsUsers(admin.id) + ":userRef");
+    allUsersRepo.reset("userRef");
+
+    Config ac = getAccountConfig(allUsersRepo);
+    ac.setString(AccountConfig.ACCOUNT, null, AccountConfig.KEY_STATUS, "OOO");
+
+    PushOneCommit.Result r =
+        pushFactory
+            .create(
+                db,
+                admin.getIdent(),
+                allUsersRepo,
+                "Update account config",
+                AccountConfig.ACCOUNT_CONFIG,
+                ac.toText())
+            .to(RefNames.REFS_USERS_SELF);
+    r.assertErrorStatus("account update not allowed");
+  }
+
   @Test
   @Sandboxed
   public void cannotCreateUserBranch() throws Exception {
@@ -1071,26 +1183,6 @@ public class AccountIT extends AbstractDaemonTest {
     assertThat(checkInfo.checkAccountsResult.problems).containsExactlyElementsIn(expectedProblems);
   }
 
-  public void create(int expectedAccountReindexCalls) throws Exception {
-    TestAccount foo = accountCreator.create("foo");
-    AccountInfo info = gApi.accounts().id(foo.id.get()).get();
-    assertThat(info.username).isEqualTo("foo");
-    accountIndexedCounter.assertReindexOf(foo, expectedAccountReindexCalls);
-
-    // check user branch
-    try (Repository repo = repoManager.openRepository(allUsers);
-        RevWalk rw = new RevWalk(repo)) {
-      Ref ref = repo.exactRef(RefNames.refsUsers(foo.getId()));
-      assertThat(ref).isNotNull();
-      RevCommit c = rw.parseCommit(ref.getObjectId());
-      long timestampDiffMs =
-          Math.abs(
-              c.getCommitTime() * 1000L
-                  - accountCache.get(foo.getId()).getAccount().getRegisteredOn().getTime());
-      assertThat(timestampDiffMs).isAtMost(ChangeRebuilderImpl.MAX_WINDOW_MS);
-    }
-  }
-
   private void assertSequenceNumbers(List<SshKeyInfo> sshKeys) {
     int seq = 1;
     for (SshKeyInfo key : sshKeys) {
@@ -1212,6 +1304,26 @@ public class AccountIT extends AbstractDaemonTest {
     assertThat(Iterables.getOnlyElement(accounts)).isEqualTo(expectedAccount.getId());
   }
 
+  private Config getAccountConfig(TestRepository<?> allUsersRepo) throws Exception {
+    Config ac = new Config();
+    try (TreeWalk tw =
+        TreeWalk.forPath(
+            allUsersRepo.getRepository(),
+            AccountConfig.ACCOUNT_CONFIG,
+            getHead(allUsersRepo.getRepository()).getTree())) {
+      assertThat(tw).isNotNull();
+      ac.fromText(
+          new String(
+              allUsersRepo
+                  .getRevWalk()
+                  .getObjectReader()
+                  .open(tw.getObjectId(0), OBJ_BLOB)
+                  .getBytes(),
+              UTF_8));
+    }
+    return ac;
+  }
+
   private static class AccountIndexedCounter implements AccountIndexedListener {
     private final AtomicLongMap<Integer> countsByAccount = AtomicLongMap.create();
 

gerrit-gpg/src/test/java/com/google/gerrit/gpg/GerritPublicKeyCheckerTest.java

@@ -37,7 +37,6 @@ import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.account.AccountManager;
-import com.google.gerrit.server.account.Accounts;
 import com.google.gerrit.server.account.AccountsUpdate;
 import com.google.gerrit.server.account.AuthRequest;
 import com.google.gerrit.server.account.externalids.ExternalId;
@@ -71,8 +70,6 @@ import org.junit.Test;
 
 /** Unit tests for {@link GerritPublicKeyChecker}. */
 public class GerritPublicKeyCheckerTest {
-  @Inject private Accounts accounts;
-
   @Inject private AccountsUpdate.Server accountsUpdate;
 
   @Inject private AccountManager accountManager;
@@ -117,10 +114,8 @@ public class GerritPublicKeyCheckerTest {
     db = schemaFactory.open();
     schemaCreator.create(db);
     userId = accountManager.authenticate(AuthRequest.forUser("user")).getAccountId();
-    Account userAccount = accounts.get(db, userId);
     // Note: does not match any key in TestKeys.
-    userAccount.setPreferredEmail("user@example.com");
-    accountsUpdate.create().update(db, userAccount);
+    accountsUpdate.create().update(db, userId, a -> a.setPreferredEmail("user@example.com"));
     user = reloadUser();
 
     requestContext.setContext(

gerrit-httpd/src/main/java/com/google/gerrit/httpd/RunAsFilter.java

@@ -42,6 +42,7 @@ import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -111,7 +112,7 @@ class RunAsFilter implements Filter {
       Account target;
       try {
         target = accountResolver.find(db.get(), runas);
-      } catch (OrmException e) {
+      } catch (OrmException | IOException | ConfigInvalidException e) {
         log.warn("cannot resolve account for " + RUN_AS, e);
         replyError(req, res, SC_INTERNAL_SERVER_ERROR, "cannot resolve " + RUN_AS, e);
         return;

gerrit-httpd/src/main/java/com/google/gerrit/httpd/auth/become/BecomeAnyAccountLoginServlet.java

@@ -49,6 +49,7 @@ import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 
@@ -231,7 +232,7 @@ class BecomeAnyAccountLoginServlet extends HttpServlet {
     }
     try (ReviewDb db = schema.open()) {
       return auth(accounts.get(db, id));
-    } catch (OrmException e) {
+    } catch (OrmException | IOException | ConfigInvalidException e) {
       getServletContext().log("cannot query database", e);
       return null;
     }

gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/AccountsOnInit.java

@@ -19,11 +19,13 @@ import static com.google.common.base.Preconditions.checkArgument;
 import com.google.common.collect.ImmutableSet;
 import com.google.gerrit.pgm.init.api.InitFlags;
 import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.GerritPersonIdentProvider;
 import com.google.gerrit.server.account.Accounts;
 import com.google.gerrit.server.account.AccountsUpdate;
 import com.google.gerrit.server.config.SitePaths;
+import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import java.io.File;
@@ -57,7 +59,15 @@ public class AccountsOnInit {
           ObjectInserter oi = repo.newObjectInserter()) {
         PersonIdent serverIdent = new GerritPersonIdentProvider(flags.cfg).get();
         AccountsUpdate.createUserBranch(
-            repo, oi, serverIdent, serverIdent, account.getId(), account.getRegisteredOn());
+            repo,
+            new Project.NameKey(allUsers),
+            GitReferenceUpdated.DISABLED,
+            null,
+            oi,
+            serverIdent,
+            serverIdent,
+            account.getId(),
+            account.getRegisteredOn());
       }
     }
   }

gerrit-server/src/main/java/com/google/gerrit/server/ReviewerRecommender.java

@@ -44,6 +44,7 @@ import com.google.gerrit.server.query.change.InternalChangeQuery;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.EnumSet;
@@ -60,6 +61,7 @@ import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Stream;
 import org.apache.commons.lang.mutable.MutableDouble;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -73,7 +75,7 @@ public class ReviewerRecommender {
       new double[] {
         BASE_REVIEWER_WEIGHT, BASE_OWNER_WEIGHT, BASE_COMMENT_WEIGHT,
       };
-  private static final long PLUGIN_QUERY_TIMEOUT = 500; //ms
+  private static final long PLUGIN_QUERY_TIMEOUT = 500; // ms
 
   private final ChangeQueryBuilder changeQueryBuilder;
   private final Config config;
@@ -108,7 +110,7 @@ public class ReviewerRecommender {
       SuggestReviewers suggestReviewers,
       ProjectControl projectControl,
       List<Account.Id> candidateList)
-      throws OrmException {
+      throws OrmException, IOException, ConfigInvalidException {
     String query = suggestReviewers.getQuery();
     double baseWeight = config.getInt("addReviewer", "baseWeight", 1);
 
@@ -196,7 +198,7 @@ public class ReviewerRecommender {
   }
 
   private Map<Account.Id, MutableDouble> baseRankingForEmptyQuery(double baseWeight)
-      throws OrmException {
+      throws OrmException, IOException, ConfigInvalidException {
     // Get the user's last 25 changes, check approvals
     try {
       List<ChangeData> result =
@@ -225,7 +227,7 @@ public class ReviewerRecommender {
 
   private Map<Account.Id, MutableDouble> baseRankingForCandidateList(
       List<Account.Id> candidates, ProjectControl projectControl, double baseWeight)
-      throws OrmException {
+      throws OrmException, IOException, ConfigInvalidException {
     // Get each reviewer's activity based on number of applied labels
     // (weighted 10d), number of comments (weighted 0.5d) and number of owned
     // changes (weighted 1d).

gerrit-server/src/main/java/com/google/gerrit/server/ReviewersUtil.java

@@ -56,6 +56,7 @@ import java.util.EnumSet;
 import java.util.List;
 import java.util.Objects;
 import java.util.Set;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 public class ReviewersUtil {
   @Singleton
@@ -146,7 +147,7 @@ public class ReviewersUtil {
       ProjectControl projectControl,
       VisibilityControl visibilityControl,
       boolean excludeGroups)
-      throws IOException, OrmException {
+      throws IOException, OrmException, ConfigInvalidException {
     String query = suggestReviewers.getQuery();
     int limit = suggestReviewers.getLimit();
 
@@ -212,7 +213,7 @@ public class ReviewersUtil {
       SuggestReviewers suggestReviewers,
       ProjectControl projectControl,
       List<Account.Id> candidateList)
-      throws OrmException {
+      throws OrmException, IOException, ConfigInvalidException {
     try (Timer0.Context ctx = metrics.recommendAccountsLatency.start()) {
       return reviewerRecommender.suggestReviewers(
           changeNotes, suggestReviewers, projectControl, candidateList);

gerrit-server/src/main/java/com/google/gerrit/server/account/AccountConfig.java

@@ -0,0 +1,260 @@
+// Copyright (C) 2017 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.account;
+
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableList;
+import com.google.gerrit.common.Nullable;
+import com.google.gerrit.common.TimeUtil;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.RefNames;
+import com.google.gerrit.server.git.ValidationError;
+import com.google.gerrit.server.git.VersionedMetaData;
+import com.google.gerrit.server.mail.send.OutgoingEmailValidator;
+import com.google.gwtorm.server.OrmDuplicateKeyException;
+import java.io.IOException;
+import java.sql.Timestamp;
+import java.util.ArrayList;
+import java.util.List;
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.lib.CommitBuilder;
+import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.revwalk.RevSort;
+
+/**
+ * ‘account.config’ file in the user branch in the All-Users repository that contains the properties
+ * of the account.
+ *
+ * <p>The 'account.config' file is a git config file that has one 'account' section with the
+ * properties of the account:
+ *
+ * <pre>
+ *   [account]
+ *     active = false
+ *     fullName = John Doe
+ *     preferredEmail = john.doe@foo.com
+ *     status = Overloaded with reviews
+ * </pre>
+ *
+ * <p>All keys are optional. This means 'account.config' may not exist on the user branch if no
+ * properties are set.
+ *
+ * <p>Not setting a key and setting a key to an empty string are treated the same way and result in
+ * a {@code null} value.
+ *
+ * <p>If no value for 'active' is specified, by default the account is considered as active.
+ *
+ * <p>The commit date of the first commit on the user branch is used as registration date of the
+ * account. The first commit may be an empty commit (if no properties were set and 'account.config'
+ * doesn't exist).
+ */
+public class AccountConfig extends VersionedMetaData implements ValidationError.Sink {
+  public static final String ACCOUNT_CONFIG = "account.config";
+  public static final String ACCOUNT = "account";
+  public static final String KEY_ACTIVE = "active";
+  public static final String KEY_FULL_NAME = "fullName";
+  public static final String KEY_PREFERRED_EMAIL = "preferredEmail";
+  public static final String KEY_STATUS = "status";
+
+  @Nullable private final OutgoingEmailValidator emailValidator;
+  private final Account.Id accountId;
+  private final String ref;
+
+  private boolean isLoaded;
+  private Account account;
+  private Timestamp registeredOn;
+  private List<ValidationError> validationErrors;
+
+  public AccountConfig(@Nullable OutgoingEmailValidator emailValidator, Account.Id accountId) {
+    this.emailValidator = emailValidator;
+    this.accountId = accountId;
+    this.ref = RefNames.refsUsers(accountId);
+  }
+
+  @Override
+  protected String getRefName() {
+    return ref;
+  }
+
+  /**
+   * Get the loaded account.
+   *
+   * @return loaded account.
+   * @throws IllegalStateException if the account was not loaded yet
+   */
+  public Account getAccount() {
+    checkLoaded();
+    return account;
+  }
+
+  /**
+   * Sets the account. This means the loaded account will be overwritten with the given account.
+   *
+   * <p>Changing the registration date of an account is not supported.
+   *
+   * @param account account that should be set
+   * @throws IllegalStateException if the account was not loaded yet
+   */
+  public void setAccount(Account account) {
+    checkLoaded();
+    this.account = account;
+    this.registeredOn = account.getRegisteredOn();
+  }
+
+  /**
+   * Creates a new account.
+   *
+   * @return the new account
+   * @throws OrmDuplicateKeyException if the user branch already exists
+   */
+  public Account getNewAccount() throws OrmDuplicateKeyException {
+    checkLoaded();
+    if (revision != null) {
+      throw new OrmDuplicateKeyException(String.format("account %s already exists", accountId));
+    }
+    this.registeredOn = TimeUtil.nowTs();
+    this.account = new Account(accountId, registeredOn);
+    return account;
+  }
+
+  @Override
+  protected void onLoad() throws IOException, ConfigInvalidException {
+    if (revision != null) {
+      rw.markStart(revision);
+      rw.sort(RevSort.REVERSE);
+      registeredOn = new Timestamp(rw.next().getCommitTime() * 1000L);
+
+      Config cfg = readConfig(ACCOUNT_CONFIG);
+
+      account = parse(cfg);
+    }
+
+    isLoaded = true;
+  }
+
+  private Account parse(Config cfg) {
+    Account account = new Account(accountId, registeredOn);
+    account.setActive(cfg.getBoolean(ACCOUNT, null, KEY_ACTIVE, true));
+    account.setFullName(get(cfg, KEY_FULL_NAME));
+
+    String preferredEmail = get(cfg, KEY_PREFERRED_EMAIL);
+    account.setPreferredEmail(preferredEmail);
+    if (emailValidator != null && !emailValidator.isValid(preferredEmail)) {
+      error(
+          new ValidationError(
+              ACCOUNT_CONFIG, String.format("Invalid preferred email: %s", preferredEmail)));
+    }
+
+    account.setStatus(get(cfg, KEY_STATUS));
+    return account;
+  }
+
+  @Override
+  protected boolean onSave(CommitBuilder commit) throws IOException, ConfigInvalidException {
+    checkLoaded();
+
+    if (revision != null) {
+      commit.setMessage("Update account\n");
+    } else if (account != null) {
+      commit.setMessage("Create account\n");
+      commit.setAuthor(new PersonIdent(commit.getAuthor(), registeredOn));
+      commit.setCommitter(new PersonIdent(commit.getCommitter(), registeredOn));
+    }
+
+    Config cfg = readConfig(ACCOUNT_CONFIG);
+    setActive(cfg, account.isActive());
+    set(cfg, KEY_FULL_NAME, account.getFullName());
+    set(cfg, KEY_PREFERRED_EMAIL, account.getPreferredEmail());
+    set(cfg, KEY_STATUS, account.getStatus());
+    saveConfig(ACCOUNT_CONFIG, cfg);
+    return true;
+  }
+
+  /**
+   * Sets/Unsets {@code account.active} in the given config.
+   *
+   * <p>{@code account.active} is set to {@code false} if the account is inactive.
+   *
+   * <p>If the account is active {@code account.active} is unset since {@code true} is the default
+   * if this field is missing.
+   *
+   * @param cfg the config
+   * @param value whether the account is active
+   */
+  private static void setActive(Config cfg, boolean value) {
+    if (!value) {
+      cfg.setBoolean(ACCOUNT, null, KEY_ACTIVE, false);
+    } else {
+      cfg.unset(ACCOUNT, null, KEY_ACTIVE);
+    }
+  }
+
+  /**
+   * Sets/Unsets the given key in the given config.
+   *
+   * <p>The key unset if the value is {@code null}.
+   *
+   * @param cfg the config
+   * @param key the key
+   * @param value the value
+   */
+  private static void set(Config cfg, String key, String value) {
+    if (!Strings.isNullOrEmpty(value)) {
+      cfg.setString(ACCOUNT, null, key, value);
+    } else {
+      cfg.unset(ACCOUNT, null, key);
+    }
+  }
+
+  /**
+   * Gets the given key from the given config.
+   *
+   * <p>Empty values are returned as {@code null}
+   *
+   * @param cfg the config
+   * @param key the key
+   * @return the value, {@code null} if key was not set or key was set to empty string
+   */
+  private static String get(Config cfg, String key) {
+    return Strings.emptyToNull(cfg.getString(ACCOUNT, null, key));
+  }
+
+  private void checkLoaded() {
+    checkState(isLoaded, "account not loaded yet");
+  }
+
+  /**
+   * Get the validation errors, if any were discovered during load.
+   *
+   * @return list of errors; empty list if there are no errors.
+   */
+  public List<ValidationError> getValidationErrors() {
+    if (validationErrors != null) {
+      return ImmutableList.copyOf(validationErrors);
+    }
+    return ImmutableList.of();
+  }
+
+  @Override
+  public void error(ValidationError error) {
+    if (validationErrors == null) {
+      validationErrors = new ArrayList<>(4);
+    }
+    validationErrors.add(error);
+  }
+}

gerrit-server/src/main/java/com/google/gerrit/server/account/AccountManager.java

@@ -16,7 +16,6 @@ package com.google.gerrit.server.account;
 
 import com.google.common.base.Strings;
 import com.google.gerrit.audit.AuditService;
-import com.google.gerrit.common.TimeUtil;
 import com.google.gerrit.common.data.AccessSection;
 import com.google.gerrit.common.data.GlobalCapability;
 import com.google.gerrit.common.data.Permission;
@@ -39,10 +38,13 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
 import org.slf4j.Logger;
@@ -150,7 +152,7 @@ public class AccountManager {
   private void update(ReviewDb db, AuthRequest who, ExternalId extId)
       throws OrmException, IOException, ConfigInvalidException {
     IdentifiedUser user = userFactory.create(extId.accountId());
-    Account toUpdate = null;
+    List<Consumer<Account>> accountUpdates = new ArrayList<>();
 
     // If the email address was modified by the authentication provider,
     // update our records to match the changed email.
@@ -159,8 +161,7 @@ public class AccountManager {
     String oldEmail = extId.email();
     if (newEmail != null && !newEmail.equals(oldEmail)) {
       if (oldEmail != null && oldEmail.equals(user.getAccount().getPreferredEmail())) {
-        toUpdate = load(toUpdate, user.getAccountId(), db);
-        toUpdate.setPreferredEmail(newEmail);
+        accountUpdates.add(a -> a.setPreferredEmail(newEmail));
       }
 
       externalIdsUpdateFactory
@@ -172,8 +173,7 @@ public class AccountManager {
     if (!realm.allowsEdit(AccountFieldName.FULL_NAME)
         && !Strings.isNullOrEmpty(who.getDisplayName())
         && !eq(user.getAccount().getFullName(), who.getDisplayName())) {
-      toUpdate = load(toUpdate, user.getAccountId(), db);
-      toUpdate.setFullName(who.getDisplayName());
+      accountUpdates.add(a -> a.setFullName(who.getDisplayName()));
     }
 
     if (!realm.allowsEdit(AccountFieldName.USER_NAME)
@@ -184,8 +184,12 @@ public class AccountManager {
               "Not changing already set username %s to %s", user.getUserName(), who.getUserName()));
     }
 
-    if (toUpdate != null) {
-      accountsUpdateFactory.create().update(db, toUpdate);
+    if (!accountUpdates.isEmpty()) {
+      Account account =
+          accountsUpdateFactory.create().update(db, user.getAccountId(), accountUpdates);
+      if (account == null) {
+        throw new OrmException("Account " + user.getAccountId() + " has been deleted");
+      }
     }
 
     if (newEmail != null && !newEmail.equals(oldEmail)) {
@@ -194,16 +198,6 @@ public class AccountManager {
     }
   }
 
-  private Account load(Account toUpdate, Account.Id accountId, ReviewDb db) throws OrmException {
-    if (toUpdate == null) {
-      toUpdate = accounts.get(db, accountId);
-      if (toUpdate == null) {
-        throw new OrmException("Account " + accountId + " has been deleted");
-      }
-    }
-    return toUpdate;
-  }
-
   private static boolean eq(String a, String b) {
     return (a == null && b == null) || (a != null && a.equals(b));
   }
@@ -211,18 +205,23 @@ public class AccountManager {
   private AuthResult create(ReviewDb db, AuthRequest who)
       throws OrmException, AccountException, IOException, ConfigInvalidException {
     Account.Id newId = new Account.Id(db.nextAccountId());
-    Account account = new Account(newId, TimeUtil.nowTs());
 
     ExternalId extId =
         ExternalId.createWithEmail(who.getExternalIdKey(), newId, who.getEmailAddress());
-    account.setFullName(who.getDisplayName());
-    account.setPreferredEmail(extId.email());
 
     boolean isFirstAccount = awaitsFirstAccountCheck.getAndSet(false) && !accounts.hasAnyAccount();
 
+    Account account;
     try {
       AccountsUpdate accountsUpdate = accountsUpdateFactory.create();
-      accountsUpdate.upsert(db, account);
+      account =
+          accountsUpdate.insert(
+              db,
+              newId,
+              a -> {
+                a.setFullName(who.getDisplayName());
+                a.setPreferredEmail(extId.email());
+              });
 
       ExternalId existingExtId = externalIds.get(extId.key());
       if (existingExtId != null && !existingExtId.accountId().equals(extId.accountId())) {
@@ -364,11 +363,16 @@ public class AccountManager {
             .insert(ExternalId.createWithEmail(who.getExternalIdKey(), to, who.getEmailAddress()));
 
         if (who.getEmailAddress() != null) {
-          Account a = accounts.get(db, to);
-          if (a.getPreferredEmail() == null) {
-            a.setPreferredEmail(who.getEmailAddress());
-            accountsUpdateFactory.create().update(db, a);
-          }
+          accountsUpdateFactory
+              .create()
+              .update(
+                  db,
+                  to,
+                  a -> {
+                    if (a.getPreferredEmail() == null) {
+                      a.setPreferredEmail(who.getEmailAddress());
+                    }
+                  });
           byEmailCache.evict(who.getEmailAddress());
         }
       }
@@ -428,12 +432,17 @@ public class AccountManager {
         externalIdsUpdateFactory.create().delete(extId);
 
         if (who.getEmailAddress() != null) {
-          Account a = accounts.get(db, from);
-          if (a.getPreferredEmail() != null
-              && a.getPreferredEmail().equals(who.getEmailAddress())) {
-            a.setPreferredEmail(null);
-            accountsUpdateFactory.create().update(db, a);
-          }
+          accountsUpdateFactory
+              .create()
+              .update(
+                  db,
+                  from,
+                  a -> {
+                    if (a.getPreferredEmail() != null
+                        && a.getPreferredEmail().equals(who.getEmailAddress())) {
+                      a.setPreferredEmail(null);
+                    }
+                  });
           byEmailCache.evict(who.getEmailAddress());
         }
 

gerrit-server/src/main/java/com/google/gerrit/server/account/AccountResolver.java

@@ -23,12 +23,14 @@ import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
+import java.io.IOException;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class AccountResolver {
@@ -61,7 +63,8 @@ public class AccountResolver {
    * @return the single account that matches; null if no account matches or there are multiple
    *     candidates.
    */
-  public Account find(ReviewDb db, String nameOrEmail) throws OrmException {
+  public Account find(ReviewDb db, String nameOrEmail)
+      throws OrmException, IOException, ConfigInvalidException {
     Set<Account.Id> r = findAll(db, nameOrEmail);
     if (r.size() == 1) {
       return byId.get(r.iterator().next()).getAccount();
@@ -90,7 +93,8 @@ public class AccountResolver {
    *     name ("username").
    * @return the accounts that match, empty collection if none. Never null.
    */
-  public Set<Account.Id> findAll(ReviewDb db, String nameOrEmail) throws OrmException {
+  public Set<Account.Id> findAll(ReviewDb db, String nameOrEmail)
+      throws OrmException, IOException, ConfigInvalidException {
     Matcher m = Pattern.compile("^.* \\(([1-9][0-9]*)\\)$").matcher(nameOrEmail);
     if (m.matches()) {
       Account.Id id = Account.Id.parse(m.group(1));
@@ -118,7 +122,8 @@ public class AccountResolver {
     return findAllByNameOrEmail(db, nameOrEmail);
   }
 
-  private boolean exists(ReviewDb db, Account.Id id) throws OrmException {
+  private boolean exists(ReviewDb db, Account.Id id)
+      throws OrmException, IOException, ConfigInvalidException {
     return accounts.get(db, id) != null;
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/account/Accounts.java

@@ -22,35 +22,70 @@ import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.RefNames;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.config.AllUsersName;
+import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.mail.send.OutgoingEmailValidator;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Objects;
 import java.util.Set;
 import java.util.stream.Stream;
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Repository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /** Class to access accounts. */
 @Singleton
 public class Accounts {
+  private static final Logger log = LoggerFactory.getLogger(Accounts.class);
+
+  private final boolean readFromGit;
   private final GitRepositoryManager repoManager;
   private final AllUsersName allUsersName;
+  private final OutgoingEmailValidator emailValidator;
 
   @Inject
-  Accounts(GitRepositoryManager repoManager, AllUsersName allUsersName) {
+  Accounts(
+      @GerritServerConfig Config cfg,
+      GitRepositoryManager repoManager,
+      AllUsersName allUsersName,
+      OutgoingEmailValidator emailValidator) {
+    this.readFromGit = cfg.getBoolean("user", null, "readAccountsFromGit", false);
     this.repoManager = repoManager;
     this.allUsersName = allUsersName;
+    this.emailValidator = emailValidator;
   }
 
-  public Account get(ReviewDb db, Account.Id accountId) throws OrmException {
+  public Account get(ReviewDb db, Account.Id accountId)
+      throws OrmException, IOException, ConfigInvalidException {
+    if (readFromGit) {
+      try (Repository repo = repoManager.openRepository(allUsersName)) {
+        return read(repo, accountId);
+      }
+    }
+
     return db.accounts().get(accountId);
   }
 
-  public List<Account> get(ReviewDb db, Collection<Account.Id> accountIds) throws OrmException {
+  public List<Account> get(ReviewDb db, Collection<Account.Id> accountIds)
+      throws OrmException, IOException, ConfigInvalidException {
+    if (readFromGit) {
+      List<Account> accounts = new ArrayList<>(accountIds.size());
+      try (Repository repo = repoManager.openRepository(allUsersName)) {
+        for (Account.Id accountId : accountIds) {
+          accounts.add(read(repo, accountId));
+        }
+      }
+      return accounts;
+    }
+
     return db.accounts().get(accountIds).toList();
   }
 
@@ -59,7 +94,22 @@ public class Accounts {
    *
    * @return all accounts
    */
-  public List<Account> all(ReviewDb db) throws OrmException {
+  public List<Account> all(ReviewDb db) throws OrmException, IOException {
+    if (readFromGit) {
+      Set<Account.Id> accountIds = allIds();
+      List<Account> accounts = new ArrayList<>(accountIds.size());
+      try (Repository repo = repoManager.openRepository(allUsersName)) {
+        for (Account.Id accountId : accountIds) {
+          try {
+            accounts.add(read(repo, accountId));
+          } catch (Exception e) {
+            log.error(String.format("Ignoring invalid account %s", accountId.get()), e);
+          }
+        }
+      }
+      return accounts;
+    }
+
     return db.accounts().all().toList();
   }
 
@@ -103,6 +153,13 @@ public class Accounts {
     }
   }
 
+  private Account read(Repository allUsersRepository, Account.Id accountId)
+      throws IOException, ConfigInvalidException {
+    AccountConfig accountConfig = new AccountConfig(emailValidator, accountId);
+    accountConfig.load(allUsersRepository);
+    return accountConfig.getAccount();
+  }
+
   private static Stream<Account.Id> readUserRefs(Repository repo) throws IOException {
     return repo.getRefDatabase()
         .getRefs(RefNames.REFS_USERS)

gerrit-server/src/main/java/com/google/gerrit/server/account/AccountsCollection.java

@@ -33,6 +33,8 @@ import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
+import java.io.IOException;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class AccountsCollection
@@ -68,7 +70,8 @@ public class AccountsCollection
 
   @Override
   public AccountResource parse(TopLevelResource root, IdString id)
-      throws ResourceNotFoundException, AuthException, OrmException {
+      throws ResourceNotFoundException, AuthException, OrmException, IOException,
+          ConfigInvalidException {
     IdentifiedUser user = parseId(id.get());
     if (user == null) {
       throw new ResourceNotFoundException(id);
@@ -89,7 +92,8 @@ public class AccountsCollection
    *     account is not visible to the calling user
    */
   public IdentifiedUser parse(String id)
-      throws AuthException, UnprocessableEntityException, OrmException {
+      throws AuthException, UnprocessableEntityException, OrmException, IOException,
+          ConfigInvalidException {
     return parseOnBehalfOf(null, id);
   }
 
@@ -104,8 +108,11 @@ public class AccountsCollection
    * @throws AuthException thrown if 'self' is used as account ID and the current user is not
    *     authenticated
    * @throws OrmException
+   * @throws ConfigInvalidException
+   * @throws IOException
    */
-  public IdentifiedUser parseId(String id) throws AuthException, OrmException {
+  public IdentifiedUser parseId(String id)
+      throws AuthException, OrmException, IOException, ConfigInvalidException {
     return parseIdOnBehalfOf(null, id);
   }
 
@@ -113,7 +120,8 @@ public class AccountsCollection
    * Like {@link #parse(String)}, but also sets the {@link CurrentUser#getRealUser()} on the result.
    */
   public IdentifiedUser parseOnBehalfOf(@Nullable CurrentUser caller, String id)
-      throws AuthException, UnprocessableEntityException, OrmException {
+      throws AuthException, UnprocessableEntityException, OrmException, IOException,
+          ConfigInvalidException {
     IdentifiedUser user = parseIdOnBehalfOf(caller, id);
     if (user == null) {
       throw new UnprocessableEntityException(String.format("Account Not Found: %s", id));
@@ -124,7 +132,7 @@ public class AccountsCollection
   }
 
   private IdentifiedUser parseIdOnBehalfOf(@Nullable CurrentUser caller, String id)
-      throws AuthException, OrmException {
+      throws AuthException, OrmException, IOException, ConfigInvalidException {
     if (id.equals("self")) {
       CurrentUser user = self.get();
       if (user.isIdentifiedUser()) {

gerrit-server/src/main/java/com/google/gerrit/server/account/AccountsUpdate.java

@@ -16,15 +16,21 @@ package com.google.gerrit.server.account;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.client.RefNames;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.config.AllUsersName;
+import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
 import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.git.MetaDataUpdate;
+import com.google.gerrit.server.index.change.ReindexAfterRefUpdate;
+import com.google.gerrit.server.mail.send.OutgoingEmailValidator;
 import com.google.gwtorm.server.OrmDuplicateKeyException;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
@@ -32,7 +38,9 @@ import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
 import java.sql.Timestamp;
+import java.util.List;
 import java.util.function.Consumer;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
@@ -46,8 +54,18 @@ import org.eclipse.jgit.lib.Repository;
 /**
  * Updates accounts.
  *
- * <p>On updating accounts this class takes care to evict them from the account cache and thus
- * triggers reindex for them.
+ * <p>The account updates are written to both ReviewDb and NoteDb.
+ *
+ * <p>In NoteDb accounts are represented as user branches in the All-Users repository. Optionally a
+ * user branch can contain a 'account.config' file that stores account properties, such as full
+ * name, preferred email, status and the active flag. The timestamp of the first commit on a user
+ * branch denotes the registration date. The initial commit on the user branch may be empty (since
+ * having an 'account.config' is optional). See {@link AccountConfig} for details of the
+ * 'account.config' file format.
+ *
+ * <p>On updating accounts the accounts are evicted from the account cache and thus reindexed. The
+ * eviction from the account cache is done by the {@link ReindexAfterRefUpdate} class which receives
+ * the event about updating the user branch that is triggered by this class.
  */
 @Singleton
 public class AccountsUpdate {
@@ -60,56 +78,38 @@ public class AccountsUpdate {
   @Singleton
   public static class Server {
     private final GitRepositoryManager repoManager;
-    private final AccountCache accountCache;
+    private final GitReferenceUpdated gitRefUpdated;
     private final AllUsersName allUsersName;
+    private final OutgoingEmailValidator emailValidator;
     private final Provider<PersonIdent> serverIdent;
+    private final Provider<MetaDataUpdate.Server> metaDataUpdateServerFactory;
 
     @Inject
     public Server(
         GitRepositoryManager repoManager,
-        AccountCache accountCache,
+        GitReferenceUpdated gitRefUpdated,
         AllUsersName allUsersName,
-        @GerritPersonIdent Provider<PersonIdent> serverIdent) {
+        OutgoingEmailValidator emailValidator,
+        @GerritPersonIdent Provider<PersonIdent> serverIdent,
+        Provider<MetaDataUpdate.Server> metaDataUpdateServerFactory) {
       this.repoManager = repoManager;
-      this.accountCache = accountCache;
+      this.gitRefUpdated = gitRefUpdated;
       this.allUsersName = allUsersName;
+      this.emailValidator = emailValidator;
       this.serverIdent = serverIdent;
+      this.metaDataUpdateServerFactory = metaDataUpdateServerFactory;
     }
 
     public AccountsUpdate create() {
       PersonIdent i = serverIdent.get();
-      return new AccountsUpdate(repoManager, accountCache, allUsersName, i, i);
-    }
-  }
-
-  /**
-   * Factory to create an AccountsUpdate instance for updating accounts by the Gerrit server.
-   *
-   * <p>Using this class will not perform reindexing for the updated accounts and they will also not
-   * be evicted from the account cache.
-   *
-   * <p>The Gerrit server identity will be used as author and committer for all commits that update
-   * the accounts.
-   */
-  @Singleton
-  public static class ServerNoReindex {
-    private final GitRepositoryManager repoManager;
-    private final AllUsersName allUsersName;
-    private final Provider<PersonIdent> serverIdent;
-
-    @Inject
-    public ServerNoReindex(
-        GitRepositoryManager repoManager,
-        AllUsersName allUsersName,
-        @GerritPersonIdent Provider<PersonIdent> serverIdent) {
-      this.repoManager = repoManager;
-      this.allUsersName = allUsersName;
-      this.serverIdent = serverIdent;
-    }
-
-    public AccountsUpdate create() {
-      PersonIdent i = serverIdent.get();
-      return new AccountsUpdate(repoManager, null, allUsersName, i, i);
+      return new AccountsUpdate(
+          repoManager,
+          gitRefUpdated,
+          null,
+          allUsersName,
+          emailValidator,
+          i,
+          () -> metaDataUpdateServerFactory.get().create(allUsersName));
     }
   }
 
@@ -122,29 +122,42 @@ public class AccountsUpdate {
   @Singleton
   public static class User {
     private final GitRepositoryManager repoManager;
-    private final AccountCache accountCache;
+    private final GitReferenceUpdated gitRefUpdated;
     private final AllUsersName allUsersName;
+    private final OutgoingEmailValidator emailValidator;
     private final Provider<PersonIdent> serverIdent;
     private final Provider<IdentifiedUser> identifiedUser;
+    private final Provider<MetaDataUpdate.User> metaDataUpdateUserFactory;
 
     @Inject
     public User(
         GitRepositoryManager repoManager,
-        AccountCache accountCache,
+        GitReferenceUpdated gitRefUpdated,
         AllUsersName allUsersName,
+        OutgoingEmailValidator emailValidator,
         @GerritPersonIdent Provider<PersonIdent> serverIdent,
-        Provider<IdentifiedUser> identifiedUser) {
+        Provider<IdentifiedUser> identifiedUser,
+        Provider<MetaDataUpdate.User> metaDataUpdateUserFactory) {
       this.repoManager = repoManager;
-      this.accountCache = accountCache;
+      this.gitRefUpdated = gitRefUpdated;
       this.allUsersName = allUsersName;
       this.serverIdent = serverIdent;
+      this.emailValidator = emailValidator;
       this.identifiedUser = identifiedUser;
+      this.metaDataUpdateUserFactory = metaDataUpdateUserFactory;
     }
 
     public AccountsUpdate create() {
+      IdentifiedUser user = identifiedUser.get();
       PersonIdent i = serverIdent.get();
       return new AccountsUpdate(
-          repoManager, accountCache, allUsersName, createPersonIdent(i, identifiedUser.get()), i);
+          repoManager,
+          gitRefUpdated,
+          user,
+          allUsersName,
+          emailValidator,
+          createPersonIdent(i, user),
+          () -> metaDataUpdateUserFactory.get().create(allUsersName));
     }
 
     private PersonIdent createPersonIdent(PersonIdent ident, IdentifiedUser user) {
@@ -153,117 +166,178 @@ public class AccountsUpdate {
   }
 
   private final GitRepositoryManager repoManager;
-  @Nullable private final AccountCache accountCache;
+  private final GitReferenceUpdated gitRefUpdated;
+  @Nullable private final IdentifiedUser currentUser;
   private final AllUsersName allUsersName;
+  private final OutgoingEmailValidator emailValidator;
   private final PersonIdent committerIdent;
-  private final PersonIdent authorIdent;
+  private final MetaDataUpdateFactory metaDataUpdateFactory;
 
   private AccountsUpdate(
       GitRepositoryManager repoManager,
-      @Nullable AccountCache accountCache,
+      GitReferenceUpdated gitRefUpdated,
+      @Nullable IdentifiedUser currentUser,
       AllUsersName allUsersName,
+      OutgoingEmailValidator emailValidator,
       PersonIdent committerIdent,
-      PersonIdent authorIdent) {
+      MetaDataUpdateFactory metaDataUpdateFactory) {
     this.repoManager = checkNotNull(repoManager, "repoManager");
-    this.accountCache = accountCache;
+    this.gitRefUpdated = checkNotNull(gitRefUpdated, "gitRefUpdated");
+    this.currentUser = currentUser;
     this.allUsersName = checkNotNull(allUsersName, "allUsersName");
+    this.emailValidator = checkNotNull(emailValidator, "emailValidator");
     this.committerIdent = checkNotNull(committerIdent, "committerIdent");
-    this.authorIdent = checkNotNull(authorIdent, "authorIdent");
+    this.metaDataUpdateFactory = checkNotNull(metaDataUpdateFactory, "metaDataUpdateFactory");
   }
 
   /**
    * Inserts a new account.
    *
+   * @param db ReviewDb
+   * @param accountId ID of the new account
+   * @param init consumer to populate the new account
+   * @return the newly created account
+   * @throws OrmException if updating the database fails
    * @throws OrmDuplicateKeyException if the account already exists
    * @throws IOException if updating the user branch fails
+   * @throws ConfigInvalidException if any of the account fields has an invalid value
    */
-  public void insert(ReviewDb db, Account account) throws OrmException, IOException {
+  public Account insert(ReviewDb db, Account.Id accountId, Consumer<Account> init)
+      throws OrmException, IOException, ConfigInvalidException {
+    AccountConfig accountConfig = read(accountId);
+    Account account = accountConfig.getNewAccount();
+    init.accept(account);
+
+    // Create in ReviewDb
     db.accounts().insert(ImmutableSet.of(account));
-    createUserBranch(account);
-    evictAccount(account.getId());
-  }
 
-  /**
-   * Inserts or updates an account.
-   *
-   * <p>If the account already exists, it is overwritten, otherwise it is inserted.
-   */
-  public void upsert(ReviewDb db, Account account) throws OrmException, IOException {
-    db.accounts().upsert(ImmutableSet.of(account));
-    createUserBranchIfNeeded(account);
-    evictAccount(account.getId());
-  }
-
-  /** Updates the account. */
-  public void update(ReviewDb db, Account account) throws OrmException, IOException {
-    db.accounts().update(ImmutableSet.of(account));
-    evictAccount(account.getId());
+    // Create in NoteDb
+    commitNew(accountConfig);
+    return account;
   }
 
   /**
    * Gets the account and updates it atomically.
    *
+   * <p>Changing the registration date of an account is not supported.
+   *
    * @param db ReviewDb
    * @param accountId ID of the account
    * @param consumer consumer to update the account, only invoked if the account exists
    * @return the updated account, {@code null} if the account doesn't exist
-   * @throws OrmException if updating the account fails
+   * @throws OrmException if updating the database fails
+   * @throws IOException if updating the user branch fails
+   * @throws ConfigInvalidException if any of the account fields has an invalid value
    */
-  public Account atomicUpdate(ReviewDb db, Account.Id accountId, Consumer<Account> consumer)
-      throws OrmException, IOException {
-    Account account =
-        db.accounts()
-            .atomicUpdate(
-                accountId,
-                a -> {
-                  consumer.accept(a);
-                  return a;
-                });
-    evictAccount(accountId);
+  public Account update(ReviewDb db, Account.Id accountId, Consumer<Account> consumer)
+      throws OrmException, IOException, ConfigInvalidException {
+    return update(db, accountId, ImmutableList.of(consumer));
+  }
+
+  /**
+   * Gets the account and updates it atomically.
+   *
+   * <p>Changing the registration date of an account is not supported.
+   *
+   * @param db ReviewDb
+   * @param accountId ID of the account
+   * @param consumers consumers to update the account, only invoked if the account exists
+   * @return the updated account, {@code null} if the account doesn't exist
+   * @throws OrmException if updating the database fails
+   * @throws IOException if updating the user branch fails
+   * @throws ConfigInvalidException if any of the account fields has an invalid value
+   */
+  public Account update(ReviewDb db, Account.Id accountId, List<Consumer<Account>> consumers)
+      throws OrmException, IOException, ConfigInvalidException {
+    if (consumers.isEmpty()) {
+      return null;
+    }
+
+    // Update in ReviewDb
+    db.accounts()
+        .atomicUpdate(
+            accountId,
+            a -> {
+              consumers.stream().forEach(c -> c.accept(a));
+              return a;
+            });
+
+    // Update in NoteDb
+    AccountConfig accountConfig = read(accountId);
+    Account account = accountConfig.getAccount();
+    consumers.stream().forEach(c -> c.accept(account));
+    commit(accountConfig);
+
     return account;
   }
 
-  /** Deletes the account. */
+  /**
+   * Replaces the account.
+   *
+   * <p>The existing account with the same account ID is overwritten by the given account. Choosing
+   * to overwrite an account means that any updates that were done to the account by a racing
+   * request after the account was read are lost. Updates are also lost if the account was read from
+   * a stale account index. This is why using {@link #update(ReviewDb,
+   * com.google.gerrit.reviewdb.client.Account.Id, Consumer)} to do an atomic update is always
+   * preferred.
+   *
+   * <p>Changing the registration date of an account is not supported.
+   *
+   * @param db ReviewDb
+   * @param account the new account
+   * @throws OrmException if updating the database fails
+   * @throws IOException if updating the user branch fails
+   * @throws ConfigInvalidException if any of the account fields has an invalid value
+   * @see #update(ReviewDb, com.google.gerrit.reviewdb.client.Account.Id, Consumer)
+   */
+  public void replace(ReviewDb db, Account account)
+      throws OrmException, IOException, ConfigInvalidException {
+    // Update in ReviewDb
+    db.accounts().update(ImmutableSet.of(account));
+
+    // Update in NoteDb
+    AccountConfig accountConfig = read(account.getId());
+    accountConfig.setAccount(account);
+    commit(accountConfig);
+  }
+
+  /**
+   * Deletes the account.
+   *
+   * @param db ReviewDb
+   * @param account the account that should be deleted
+   * @throws OrmException if updating the database fails
+   * @throws IOException if updating the user branch fails
+   */
   public void delete(ReviewDb db, Account account) throws OrmException, IOException {
+    // Delete in ReviewDb
     db.accounts().delete(ImmutableSet.of(account));
+
+    // Delete in NoteDb
     deleteUserBranch(account.getId());
-    evictAccount(account.getId());
   }
 
-  /** Deletes the account. */
+  /**
+   * Deletes the account.
+   *
+   * @param db ReviewDb
+   * @param accountId the ID of the account that should be deleted
+   * @throws OrmException if updating the database fails
+   * @throws IOException if updating the user branch fails
+   */
   public void deleteByKey(ReviewDb db, Account.Id accountId) throws OrmException, IOException {
+    // Delete in ReviewDb
     db.accounts().deleteKeys(ImmutableSet.of(accountId));
+
+    // Delete in NoteDb
     deleteUserBranch(accountId);
-    evictAccount(accountId);
-  }
-
-  private void createUserBranch(Account account) throws IOException {
-    try (Repository repo = repoManager.openRepository(allUsersName);
-        ObjectInserter oi = repo.newObjectInserter()) {
-      String refName = RefNames.refsUsers(account.getId());
-      if (repo.exactRef(refName) != null) {
-        throw new IOException(
-            String.format(
-                "User branch %s for newly created account %s already exists.",
-                refName, account.getId().get()));
-      }
-      createUserBranch(
-          repo, oi, committerIdent, authorIdent, account.getId(), account.getRegisteredOn());
-    }
-  }
-
-  private void createUserBranchIfNeeded(Account account) throws IOException {
-    try (Repository repo = repoManager.openRepository(allUsersName);
-        ObjectInserter oi = repo.newObjectInserter()) {
-      if (repo.exactRef(RefNames.refsUsers(account.getId())) == null) {
-        createUserBranch(
-            repo, oi, committerIdent, authorIdent, account.getId(), account.getRegisteredOn());
-      }
-    }
   }
 
   public static void createUserBranch(
       Repository repo,
+      Project.NameKey project,
+      GitReferenceUpdated gitRefUpdated,
+      @Nullable IdentifiedUser user,
       ObjectInserter oi,
       PersonIdent committerIdent,
       PersonIdent authorIdent,
@@ -283,6 +357,7 @@ public class AccountsUpdate {
     if (result != Result.NEW) {
       throw new IOException(String.format("Failed to update ref %s: %s", refName, result.name()));
     }
+    gitRefUpdated.fire(project, ru, user != null ? user.getAccount() : null);
   }
 
   private static ObjectId createInitialEmptyCommit(
@@ -307,12 +382,18 @@ public class AccountsUpdate {
 
   private void deleteUserBranch(Account.Id accountId) throws IOException {
     try (Repository repo = repoManager.openRepository(allUsersName)) {
-      deleteUserBranch(repo, committerIdent, accountId);
+      deleteUserBranch(repo, allUsersName, gitRefUpdated, currentUser, committerIdent, accountId);
     }
   }
 
   public static void deleteUserBranch(
-      Repository repo, PersonIdent refLogIdent, Account.Id accountId) throws IOException {
+      Repository repo,
+      Project.NameKey project,
+      GitReferenceUpdated gitRefUpdated,
+      @Nullable IdentifiedUser user,
+      PersonIdent refLogIdent,
+      Account.Id accountId)
+      throws IOException {
     String refName = RefNames.refsUsers(accountId);
     Ref ref = repo.exactRef(refName);
     if (ref == null) {
@@ -329,11 +410,37 @@ public class AccountsUpdate {
     if (result != Result.FORCED) {
       throw new IOException(String.format("Failed to delete ref %s: %s", refName, result.name()));
     }
+    gitRefUpdated.fire(project, ru, user != null ? user.getAccount() : null);
   }
 
-  private void evictAccount(Account.Id accountId) throws IOException {
-    if (accountCache != null) {
-      accountCache.evict(accountId);
+  private AccountConfig read(Account.Id accountId) throws IOException, ConfigInvalidException {
+    try (Repository repo = repoManager.openRepository(allUsersName)) {
+      AccountConfig accountConfig = new AccountConfig(emailValidator, accountId);
+      accountConfig.load(repo);
+      return accountConfig;
     }
   }
+
+  private void commitNew(AccountConfig accountConfig) throws IOException {
+    // When creating a new account we must allow empty commits so that the user branch gets created
+    // with an empty commit when no account properties are set and hence no 'account.config' file
+    // will be created.
+    commit(accountConfig, true);
+  }
+
+  private void commit(AccountConfig accountConfig) throws IOException {
+    commit(accountConfig, false);
+  }
+
+  private void commit(AccountConfig accountConfig, boolean allowEmptyCommit) throws IOException {
+    try (MetaDataUpdate md = metaDataUpdateFactory.create()) {
+      md.setAllowEmpty(allowEmptyCommit);
+      accountConfig.commit(md);
+    }
+  }
+
+  @FunctionalInterface
+  private static interface MetaDataUpdateFactory {
+    MetaDataUpdate create() throws IOException;
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/account/CreateAccount.java

@@ -17,7 +17,7 @@ package com.google.gerrit.server.account;
 import static com.google.gerrit.server.account.externalids.ExternalId.SCHEME_MAILTO;
 
 import com.google.gerrit.audit.AuditService;
-import com.google.gerrit.common.TimeUtil;
+import com.google.gerrit.common.Nullable;
 import com.google.gerrit.common.data.GlobalCapability;
 import com.google.gerrit.common.data.GroupDescriptions;
 import com.google.gerrit.common.errors.InvalidSshKeyException;
@@ -113,12 +113,15 @@ public class CreateAccount implements RestModifyView<TopLevelResource, AccountIn
   }
 
   @Override
-  public Response<AccountInfo> apply(TopLevelResource rsrc, AccountInput input)
+  public Response<AccountInfo> apply(TopLevelResource rsrc, @Nullable AccountInput input)
+      throws BadRequestException, ResourceConflictException, UnprocessableEntityException,
+          OrmException, IOException, ConfigInvalidException {
+    return apply(input != null ? input : new AccountInput());
+  }
+
+  public Response<AccountInfo> apply(AccountInput input)
       throws BadRequestException, ResourceConflictException, UnprocessableEntityException,
           OrmException, IOException, ConfigInvalidException {
-    if (input == null) {
-      input = new AccountInput();
-    }
     if (input.username != null && !username.equals(input.username)) {
       throw new BadRequestException("username must match URL");
     }
@@ -171,10 +174,15 @@ public class CreateAccount implements RestModifyView<TopLevelResource, AccountIn
       }
     }
 
-    Account a = new Account(id, TimeUtil.nowTs());
-    a.setFullName(input.name);
-    a.setPreferredEmail(input.email);
-    accountsUpdate.create().insert(db, a);
+    accountsUpdate
+        .create()
+        .insert(
+            db,
+            id,
+            a -> {
+              a.setFullName(input.name);
+              a.setPreferredEmail(input.email);
+            });
 
     for (AccountGroup.Id groupId : groups) {
       AccountGroupMember m = new AccountGroupMember(new AccountGroupMember.Key(id, groupId));

gerrit-server/src/main/java/com/google/gerrit/server/account/DeleteActive.java

@@ -31,6 +31,7 @@ import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicBoolean;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @RequiresCapability(GlobalCapability.MODIFY_ACCOUNT)
 @Singleton
@@ -53,7 +54,7 @@ public class DeleteActive implements RestModifyView<AccountResource, Input> {
 
   @Override
   public Response<?> apply(AccountResource rsrc, Input input)
-      throws RestApiException, OrmException, IOException {
+      throws RestApiException, OrmException, IOException, ConfigInvalidException {
     if (self.get() == rsrc.getUser()) {
       throw new ResourceConflictException("cannot deactivate own account");
     }
@@ -62,7 +63,7 @@ public class DeleteActive implements RestModifyView<AccountResource, Input> {
     Account account =
         accountsUpdate
             .create()
-            .atomicUpdate(
+            .update(
                 dbProvider.get(),
                 rsrc.getUser().getAccountId(),
                 a -> {

gerrit-server/src/main/java/com/google/gerrit/server/account/PutActive.java

@@ -28,6 +28,7 @@ import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicBoolean;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @RequiresCapability(GlobalCapability.MODIFY_ACCOUNT)
 @Singleton
@@ -45,12 +46,12 @@ public class PutActive implements RestModifyView<AccountResource, Input> {
 
   @Override
   public Response<String> apply(AccountResource rsrc, Input input)
-      throws ResourceNotFoundException, OrmException, IOException {
+      throws ResourceNotFoundException, OrmException, IOException, ConfigInvalidException {
     AtomicBoolean alreadyActive = new AtomicBoolean(false);
     Account account =
         accountsUpdate
             .create()
-            .atomicUpdate(
+            .update(
                 dbProvider.get(),
                 rsrc.getUser().getAccountId(),
                 a -> {

gerrit-server/src/main/java/com/google/gerrit/server/account/PutName.java

@@ -35,6 +35,7 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class PutName implements RestModifyView<AccountResource, Input> {
@@ -65,7 +66,7 @@ public class PutName implements RestModifyView<AccountResource, Input> {
   @Override
   public Response<String> apply(AccountResource rsrc, Input input)
       throws AuthException, MethodNotAllowedException, ResourceNotFoundException, OrmException,
-          IOException, PermissionBackendException {
+          IOException, PermissionBackendException, ConfigInvalidException {
     if (self.get() != rsrc.getUser()) {
       permissionBackend.user(self).check(GlobalPermission.MODIFY_ACCOUNT);
     }
@@ -73,7 +74,8 @@ public class PutName implements RestModifyView<AccountResource, Input> {
   }
 
   public Response<String> apply(IdentifiedUser user, Input input)
-      throws MethodNotAllowedException, ResourceNotFoundException, OrmException, IOException {
+      throws MethodNotAllowedException, ResourceNotFoundException, OrmException, IOException,
+          ConfigInvalidException {
     if (input == null) {
       input = new Input();
     }
@@ -86,7 +88,7 @@ public class PutName implements RestModifyView<AccountResource, Input> {
     Account account =
         accountsUpdate
             .create()
-            .atomicUpdate(dbProvider.get(), user.getAccountId(), a -> a.setFullName(newName));
+            .update(dbProvider.get(), user.getAccountId(), a -> a.setFullName(newName));
     if (account == null) {
       throw new ResourceNotFoundException("account not found");
     }

gerrit-server/src/main/java/com/google/gerrit/server/account/PutPreferred.java

@@ -32,6 +32,7 @@ import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicBoolean;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class PutPreferred implements RestModifyView<AccountResource.Email, Input> {
@@ -57,7 +58,7 @@ public class PutPreferred implements RestModifyView<AccountResource.Email, Input
   @Override
   public Response<String> apply(AccountResource.Email rsrc, Input input)
       throws AuthException, ResourceNotFoundException, OrmException, IOException,
-          PermissionBackendException {
+          PermissionBackendException, ConfigInvalidException {
     if (self.get() != rsrc.getUser()) {
       permissionBackend.user(self).check(GlobalPermission.MODIFY_ACCOUNT);
     }
@@ -65,12 +66,12 @@ public class PutPreferred implements RestModifyView<AccountResource.Email, Input
   }
 
   public Response<String> apply(IdentifiedUser user, String email)
-      throws ResourceNotFoundException, OrmException, IOException {
+      throws ResourceNotFoundException, OrmException, IOException, ConfigInvalidException {
     AtomicBoolean alreadyPreferred = new AtomicBoolean(false);
     Account account =
         accountsUpdate
             .create()
-            .atomicUpdate(
+            .update(
                 dbProvider.get(),
                 user.getAccountId(),
                 a -> {

gerrit-server/src/main/java/com/google/gerrit/server/account/PutStatus.java

@@ -33,6 +33,7 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class PutStatus implements RestModifyView<AccountResource, Input> {
@@ -66,7 +67,7 @@ public class PutStatus implements RestModifyView<AccountResource, Input> {
   @Override
   public Response<String> apply(AccountResource rsrc, Input input)
       throws AuthException, ResourceNotFoundException, OrmException, IOException,
-          PermissionBackendException {
+          PermissionBackendException, ConfigInvalidException {
     if (self.get() != rsrc.getUser()) {
       permissionBackend.user(self).check(GlobalPermission.MODIFY_ACCOUNT);
     }
@@ -74,7 +75,7 @@ public class PutStatus implements RestModifyView<AccountResource, Input> {
   }
 
   public Response<String> apply(IdentifiedUser user, Input input)
-      throws ResourceNotFoundException, OrmException, IOException {
+      throws ResourceNotFoundException, OrmException, IOException, ConfigInvalidException {
     if (input == null) {
       input = new Input();
     }
@@ -83,7 +84,7 @@ public class PutStatus implements RestModifyView<AccountResource, Input> {
     Account account =
         accountsUpdate
             .create()
-            .atomicUpdate(
+            .update(
                 dbProvider.get(),
                 user.getAccountId(),
                 a -> a.setStatus(Strings.nullToEmpty(newStatus)));

gerrit-server/src/main/java/com/google/gerrit/server/args4j/AccountIdHandler.java

@@ -27,6 +27,7 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.assistedinject.Assisted;
 import java.io.IOException;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.kohsuke.args4j.CmdLineException;
 import org.kohsuke.args4j.CmdLineParser;
 import org.kohsuke.args4j.OptionDef;
@@ -82,8 +83,12 @@ public class AccountIdHandler extends OptionHandler<Account.Id> {
             throw new CmdLineException(owner, "user \"" + token + "\" not found");
         }
       }
-    } catch (OrmException | IOException e) {
+    } catch (OrmException e) {
       throw new CmdLineException(owner, "database is down");
+    } catch (IOException e) {
+      throw new CmdLineException(owner, "Failed to load account", e);
+    } catch (ConfigInvalidException e) {
+      throw new CmdLineException(owner, "Invalid account config", e);
     }
     setter.addValue(accountId);
     return 1;

gerrit-server/src/main/java/com/google/gerrit/server/change/Abandon.java

@@ -41,7 +41,9 @@ import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
+import java.io.IOException;
 import java.util.Collection;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class Abandon extends RetryingRestModifyView<ChangeResource, AbandonInput, ChangeInfo>
@@ -68,7 +70,8 @@ public class Abandon extends RetryingRestModifyView<ChangeResource, AbandonInput
   @Override
   protected ChangeInfo applyImpl(
       BatchUpdate.Factory updateFactory, ChangeResource req, AbandonInput input)
-      throws RestApiException, UpdateException, OrmException, PermissionBackendException {
+      throws RestApiException, UpdateException, OrmException, PermissionBackendException,
+          IOException, ConfigInvalidException {
     req.permissions().database(dbProvider).check(ChangePermission.ABANDON);
 
     NotifyHandling notify = input.notify == null ? defaultNotify(req.getControl()) : input.notify;

gerrit-server/src/main/java/com/google/gerrit/server/change/CherryPick.java

@@ -39,6 +39,7 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class CherryPick
@@ -67,7 +68,7 @@ public class CherryPick
   public ChangeInfo applyImpl(
       BatchUpdate.Factory updateFactory, RevisionResource rsrc, CherryPickInput input)
       throws OrmException, IOException, UpdateException, RestApiException,
-          PermissionBackendException {
+          PermissionBackendException, ConfigInvalidException {
     input.parent = input.parent == null ? 1 : input.parent;
     if (input.message == null || input.message.trim().isEmpty()) {
       throw new BadRequestException("message must be non-empty");

gerrit-server/src/main/java/com/google/gerrit/server/change/CherryPickChange.java

@@ -62,6 +62,7 @@ import java.io.IOException;
 import java.sql.Timestamp;
 import java.util.List;
 import java.util.TimeZone;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.errors.InvalidObjectIdException;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectInserter;
@@ -124,7 +125,7 @@ public class CherryPickChange {
       CherryPickInput input,
       RefControl refControl)
       throws OrmException, IOException, InvalidChangeOperationException, IntegrationException,
-          UpdateException, RestApiException {
+          UpdateException, RestApiException, ConfigInvalidException {
     return cherryPick(
         batchUpdateFactory,
         change.getId(),
@@ -148,7 +149,7 @@ public class CherryPickChange {
       CherryPickInput input,
       RefControl destRefControl)
       throws OrmException, IOException, InvalidChangeOperationException, IntegrationException,
-          UpdateException, RestApiException {
+          UpdateException, RestApiException, ConfigInvalidException {
 
     IdentifiedUser identifiedUser = user.get();
     try (Repository git = gitManager.openRepository(project);
@@ -320,7 +321,7 @@ public class CherryPickChange {
       ChangeControl destCtl,
       CodeReviewCommit cherryPickCommit,
       CherryPickInput input)
-      throws IOException, OrmException, BadRequestException {
+      throws IOException, OrmException, BadRequestException, ConfigInvalidException {
     Change destChange = destCtl.getChange();
     PatchSet.Id psId = ChangeUtil.nextPatchSetId(git, destChange.currentPatchSetId());
     PatchSet current = psUtil.current(dbProvider.get(), destCtl.getNotes());
@@ -343,7 +344,7 @@ public class CherryPickChange {
       Branch.NameKey sourceBranch,
       ObjectId sourceCommit,
       CherryPickInput input)
-      throws OrmException, IOException, BadRequestException {
+      throws OrmException, IOException, BadRequestException, ConfigInvalidException {
     Change.Id changeId = new Change.Id(seq.nextChangeId());
     ChangeInserter ins =
         changeInserterFactory.create(changeId, cherryPickCommit, refName).setTopic(topic);

gerrit-server/src/main/java/com/google/gerrit/server/change/CherryPickCommit.java

@@ -39,6 +39,7 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.revwalk.RevCommit;
 
 @Singleton
@@ -67,7 +68,7 @@ public class CherryPickCommit
   public ChangeInfo applyImpl(
       BatchUpdate.Factory updateFactory, CommitResource rsrc, CherryPickInput input)
       throws OrmException, IOException, UpdateException, RestApiException,
-          PermissionBackendException {
+          PermissionBackendException, ConfigInvalidException {
     RevCommit commit = rsrc.getCommit();
     String message = Strings.nullToEmpty(input.message).trim();
     input.message = message.isEmpty() ? commit.getFullMessage() : message;

gerrit-server/src/main/java/com/google/gerrit/server/change/ConsistencyChecker.java

@@ -68,6 +68,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
@@ -226,7 +227,7 @@ public class ConsistencyChecker {
       if (accounts.get(db.get(), change().getOwner()) == null) {
         problem("Missing change owner: " + change().getOwner());
       }
-    } catch (OrmException e) {
+    } catch (OrmException | IOException | ConfigInvalidException e) {
       error("Failed to look up owner", e);
     }
   }

gerrit-server/src/main/java/com/google/gerrit/server/change/CreateChange.java

@@ -74,6 +74,7 @@ import java.sql.Timestamp;
 import java.util.Collections;
 import java.util.List;
 import java.util.TimeZone;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.ObjectId;
@@ -151,7 +152,7 @@ public class CreateChange
   protected Response<ChangeInfo> applyImpl(
       BatchUpdate.Factory updateFactory, TopLevelResource parent, ChangeInput input)
       throws OrmException, IOException, InvalidChangeOperationException, RestApiException,
-          UpdateException, PermissionBackendException {
+          UpdateException, PermissionBackendException, ConfigInvalidException {
     if (Strings.isNullOrEmpty(input.project)) {
       throw new BadRequestException("project must be non-empty");
     }

gerrit-server/src/main/java/com/google/gerrit/server/change/NotifyUtil.java

@@ -31,10 +31,12 @@ import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class NotifyUtil {
@@ -76,7 +78,7 @@ public class NotifyUtil {
 
   public ListMultimap<RecipientType, Account.Id> resolveAccounts(
       @Nullable Map<RecipientType, NotifyInfo> notifyDetails)
-      throws OrmException, BadRequestException {
+      throws OrmException, BadRequestException, IOException, ConfigInvalidException {
     if (isNullOrEmpty(notifyDetails)) {
       return ImmutableListMultimap.of();
     }
@@ -96,7 +98,7 @@ public class NotifyUtil {
   }
 
   private List<Account.Id> find(ReviewDb db, List<String> nameOrEmails)
-      throws OrmException, BadRequestException {
+      throws OrmException, BadRequestException, IOException, ConfigInvalidException {
     List<String> missing = new ArrayList<>(nameOrEmails.size());
     List<Account.Id> r = new ArrayList<>(nameOrEmails.size());
     for (String nameOrEmail : nameOrEmails) {

gerrit-server/src/main/java/com/google/gerrit/server/change/PostReview.java

@@ -126,6 +126,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.OptionalInt;
 import java.util.Set;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
 
 @Singleton
@@ -190,14 +191,14 @@ public class PostReview
   protected Response<ReviewResult> applyImpl(
       BatchUpdate.Factory updateFactory, RevisionResource revision, ReviewInput input)
       throws RestApiException, UpdateException, OrmException, IOException,
-          PermissionBackendException {
+          PermissionBackendException, ConfigInvalidException {
     return apply(updateFactory, revision, input, TimeUtil.nowTs());
   }
 
   public Response<ReviewResult> apply(
       BatchUpdate.Factory updateFactory, RevisionResource revision, ReviewInput input, Timestamp ts)
       throws RestApiException, UpdateException, OrmException, IOException,
-          PermissionBackendException {
+          PermissionBackendException, ConfigInvalidException {
     // Respect timestamp, but truncate at change created-on time.
     ts = Ordering.natural().max(ts, revision.getChange().getCreatedOn());
     if (revision.getEdit().isPresent()) {
@@ -367,7 +368,7 @@ public class PostReview
 
   private RevisionResource onBehalfOf(RevisionResource rev, ReviewInput in)
       throws BadRequestException, AuthException, UnprocessableEntityException, OrmException,
-          PermissionBackendException {
+          PermissionBackendException, IOException, ConfigInvalidException {
     if (in.labels == null || in.labels.isEmpty()) {
       throw new AuthException(
           String.format("label required to post review on behalf of \"%s\"", in.onBehalfOf));

gerrit-server/src/main/java/com/google/gerrit/server/change/PostReviewers.java

@@ -76,6 +76,7 @@ import java.text.MessageFormat;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
 
 @Singleton
@@ -148,7 +149,7 @@ public class PostReviewers
   protected AddReviewerResult applyImpl(
       BatchUpdate.Factory updateFactory, ChangeResource rsrc, AddReviewerInput input)
       throws IOException, OrmException, RestApiException, UpdateException,
-          PermissionBackendException {
+          PermissionBackendException, ConfigInvalidException {
     if (input.reviewer == null) {
       throw new BadRequestException("missing reviewer field");
     }
@@ -170,7 +171,7 @@ public class PostReviewers
 
   public Addition prepareApplication(
       ChangeResource rsrc, AddReviewerInput input, boolean allowGroup)
-      throws OrmException, IOException, PermissionBackendException {
+      throws OrmException, IOException, PermissionBackendException, ConfigInvalidException {
     String reviewer = input.reviewer;
     ReviewerState state = input.state();
     NotifyHandling notify = input.notify;
@@ -219,7 +220,7 @@ public class PostReviewers
       ListMultimap<RecipientType, Account.Id> accountsToNotify,
       boolean allowGroup,
       boolean allowByEmail)
-      throws OrmException, PermissionBackendException {
+      throws OrmException, PermissionBackendException, IOException, ConfigInvalidException {
     Account.Id accountId = null;
     try {
       accountId = accounts.parse(reviewer).getAccountId();

gerrit-server/src/main/java/com/google/gerrit/server/change/PreviewSubmit.java

@@ -45,6 +45,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Collection;
 import org.apache.commons.compress.archivers.ArchiveOutputStream;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.NullProgressMonitor;
 import org.eclipse.jgit.lib.ObjectId;
@@ -82,7 +83,7 @@ public class PreviewSubmit implements RestReadView<RevisionResource> {
 
   @Override
   public BinaryResult apply(RevisionResource rsrc)
-      throws OrmException, RestApiException, UpdateException {
+      throws OrmException, RestApiException, UpdateException, IOException, ConfigInvalidException {
     if (Strings.isNullOrEmpty(format)) {
       throw new BadRequestException("format is not specified");
     }
@@ -110,7 +111,7 @@ public class PreviewSubmit implements RestReadView<RevisionResource> {
   }
 
   private BinaryResult getBundles(RevisionResource rsrc, ArchiveFormat f)
-      throws OrmException, RestApiException, UpdateException {
+      throws OrmException, RestApiException, UpdateException, IOException, ConfigInvalidException {
     ReviewDb db = dbProvider.get();
     ChangeControl control = rsrc.getControl();
     IdentifiedUser caller = control.getUser().asIdentifiedUser();
@@ -125,7 +126,12 @@ public class PreviewSubmit implements RestReadView<RevisionResource> {
           .setContentType(f.getMimeType())
           .setAttachmentName("submit-preview-" + change.getChangeId() + "." + format);
       return bin;
-    } catch (OrmException | RestApiException | UpdateException | RuntimeException e) {
+    } catch (OrmException
+        | RestApiException
+        | UpdateException
+        | IOException
+        | ConfigInvalidException
+        | RuntimeException e) {
       op.close();
       throw e;
     }

gerrit-server/src/main/java/com/google/gerrit/server/change/PublishChangeEdit.java

@@ -35,6 +35,7 @@ import com.google.inject.Inject;
 import com.google.inject.Singleton;
 import java.io.IOException;
 import java.util.Optional;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class PublishChangeEdit
@@ -85,7 +86,8 @@ public class PublishChangeEdit
     @Override
     protected Response<?> applyImpl(
         BatchUpdate.Factory updateFactory, ChangeResource rsrc, PublishChangeEditInput in)
-        throws IOException, OrmException, RestApiException, UpdateException {
+        throws IOException, OrmException, RestApiException, UpdateException,
+            ConfigInvalidException {
       CreateChange.checkValidCLA(rsrc.getControl().getProjectControl());
       Optional<ChangeEdit> edit = editUtil.byChange(rsrc.getChange());
       if (!edit.isPresent()) {

gerrit-server/src/main/java/com/google/gerrit/server/change/PutAssignee.java

@@ -42,6 +42,7 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class PutAssignee extends RetryingRestModifyView<ChangeResource, AssigneeInput, AccountInfo>
@@ -73,7 +74,7 @@ public class PutAssignee extends RetryingRestModifyView<ChangeResource, Assignee
   protected AccountInfo applyImpl(
       BatchUpdate.Factory updateFactory, ChangeResource rsrc, AssigneeInput input)
       throws RestApiException, UpdateException, OrmException, IOException,
-          PermissionBackendException {
+          PermissionBackendException, ConfigInvalidException {
     rsrc.permissions().check(ChangePermission.EDIT_ASSIGNEE);
 
     input.assignee = Strings.nullToEmpty(input.assignee).trim();
@@ -109,7 +110,7 @@ public class PutAssignee extends RetryingRestModifyView<ChangeResource, Assignee
   }
 
   private Addition addAssigneeAsCC(ChangeResource rsrc, String assignee)
-      throws OrmException, IOException, PermissionBackendException {
+      throws OrmException, IOException, PermissionBackendException, ConfigInvalidException {
     AddReviewerInput reviewerInput = new AddReviewerInput();
     reviewerInput.reviewer = assignee;
     reviewerInput.state = ReviewerState.CC;

gerrit-server/src/main/java/com/google/gerrit/server/change/PutMessage.java

@@ -51,6 +51,7 @@ import java.util.TimeZone;
 import javax.inject.Inject;
 import javax.inject.Provider;
 import javax.inject.Singleton;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
@@ -107,7 +108,7 @@ public class PutMessage
   protected Response<String> applyImpl(
       BatchUpdate.Factory updateFactory, ChangeResource resource, Input input)
       throws IOException, UnchangedCommitMessageException, RestApiException, UpdateException,
-          PermissionBackendException, OrmException {
+          PermissionBackendException, OrmException, ConfigInvalidException {
     PatchSet ps = psUtil.current(db.get(), resource.getNotes());
     if (ps == null) {
       throw new ResourceConflictException("current revision is missing");

gerrit-server/src/main/java/com/google/gerrit/server/change/Reviewers.java

@@ -30,7 +30,9 @@ import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
+import java.io.IOException;
 import java.util.Collection;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class Reviewers implements ChildCollection<ChangeResource, ReviewerResource> {
@@ -69,7 +71,8 @@ public class Reviewers implements ChildCollection<ChangeResource, ReviewerResour
 
   @Override
   public ReviewerResource parse(ChangeResource rsrc, IdString id)
-      throws OrmException, ResourceNotFoundException, AuthException {
+      throws OrmException, ResourceNotFoundException, AuthException, IOException,
+          ConfigInvalidException {
     Address address = Address.tryParse(id.get());
 
     Account.Id accountId = null;

gerrit-server/src/main/java/com/google/gerrit/server/change/RevisionReviewers.java

@@ -31,7 +31,9 @@ import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
+import java.io.IOException;
 import java.util.Collection;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class RevisionReviewers implements ChildCollection<RevisionResource, ReviewerResource> {
@@ -70,7 +72,8 @@ public class RevisionReviewers implements ChildCollection<RevisionResource, Revi
 
   @Override
   public ReviewerResource parse(RevisionResource rsrc, IdString id)
-      throws OrmException, ResourceNotFoundException, AuthException, MethodNotAllowedException {
+      throws OrmException, ResourceNotFoundException, AuthException, MethodNotAllowedException,
+          IOException, ConfigInvalidException {
     if (!rsrc.isCurrent()) {
       throw new MethodNotAllowedException("Cannot access on non-current patch set");
     }

gerrit-server/src/main/java/com/google/gerrit/server/change/Submit.java

@@ -73,6 +73,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Queue;
 import java.util.Set;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.ObjectId;
@@ -202,7 +203,7 @@ public class Submit
   @Override
   public Output apply(RevisionResource rsrc, SubmitInput input)
       throws RestApiException, RepositoryNotFoundException, IOException, OrmException,
-          PermissionBackendException, UpdateException {
+          PermissionBackendException, UpdateException, ConfigInvalidException {
     input.onBehalfOf = Strings.emptyToNull(input.onBehalfOf);
     IdentifiedUser submitter;
     if (input.onBehalfOf != null) {
@@ -216,7 +217,7 @@ public class Submit
   }
 
   public Change mergeChange(RevisionResource rsrc, IdentifiedUser submitter, SubmitInput input)
-      throws OrmException, RestApiException, IOException, UpdateException {
+      throws OrmException, RestApiException, IOException, UpdateException, ConfigInvalidException {
     Change change = rsrc.getChange();
     if (!change.getStatus().isOpen()) {
       throw new ResourceConflictException("change is " + ChangeUtil.status(change));
@@ -249,7 +250,7 @@ public class Submit
         if (msg != null) {
           throw new ResourceConflictException(msg.getMessage());
         }
-        //$FALL-THROUGH$
+        // $FALL-THROUGH$
       case ABANDONED:
       case DRAFT:
       default:
@@ -478,7 +479,8 @@ public class Submit
   }
 
   private IdentifiedUser onBehalfOf(RevisionResource rsrc, SubmitInput in)
-      throws AuthException, UnprocessableEntityException, OrmException, PermissionBackendException {
+      throws AuthException, UnprocessableEntityException, OrmException, PermissionBackendException,
+          IOException, ConfigInvalidException {
     PermissionBackend.ForChange perm = rsrc.permissions().database(dbProvider);
     perm.check(ChangePermission.SUBMIT);
     perm.check(ChangePermission.SUBMIT_AS);
@@ -527,7 +529,7 @@ public class Submit
     @Override
     public ChangeInfo apply(ChangeResource rsrc, SubmitInput input)
         throws RestApiException, RepositoryNotFoundException, IOException, OrmException,
-            PermissionBackendException, UpdateException {
+            PermissionBackendException, UpdateException, ConfigInvalidException {
       PatchSet ps = psUtil.current(dbProvider.get(), rsrc.getNotes());
       if (ps == null) {
         throw new ResourceConflictException("current revision is missing");

gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestChangeReviewers.java

@@ -34,6 +34,7 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 import java.io.IOException;
 import java.util.List;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
 import org.kohsuke.args4j.Option;
 
@@ -66,7 +67,7 @@ public class SuggestChangeReviewers extends SuggestReviewers
 
   @Override
   public List<SuggestedReviewerInfo> apply(ChangeResource rsrc)
-      throws AuthException, BadRequestException, OrmException, IOException {
+      throws AuthException, BadRequestException, OrmException, IOException, ConfigInvalidException {
     if (!self.get().isIdentifiedUser()) {
       throw new AuthException("Authentication required");
     }

gerrit-server/src/main/java/com/google/gerrit/server/config/CheckAccess.java

@@ -39,6 +39,7 @@ import com.google.inject.Provider;
 import com.google.inject.Singleton;
 import java.io.IOException;
 import javax.servlet.http.HttpServletResponse;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class CheckAccess implements RestModifyView<ConfigResource, AccessCheckInput> {
@@ -67,7 +68,8 @@ public class CheckAccess implements RestModifyView<ConfigResource, AccessCheckIn
 
   @Override
   public AccessCheckInfo apply(ConfigResource unused, AccessCheckInput input)
-      throws OrmException, PermissionBackendException, RestApiException, IOException {
+      throws OrmException, PermissionBackendException, RestApiException, IOException,
+          ConfigInvalidException {
     permissionBackend.user(currentUser.get()).check(GlobalPermission.ADMINISTRATE_SERVER);
 
     if (input == null) {

gerrit-server/src/main/java/com/google/gerrit/server/config/GerritGlobalModule.java

@@ -126,6 +126,7 @@ import com.google.gerrit.server.git.strategy.SubmitStrategy;
 import com.google.gerrit.server.git.validators.CommitValidationListener;
 import com.google.gerrit.server.git.validators.MergeValidationListener;
 import com.google.gerrit.server.git.validators.MergeValidators;
+import com.google.gerrit.server.git.validators.MergeValidators.AccountValidator;
 import com.google.gerrit.server.git.validators.MergeValidators.ProjectConfigValidator;
 import com.google.gerrit.server.git.validators.OnSubmitValidationListener;
 import com.google.gerrit.server.git.validators.OnSubmitValidators;
@@ -389,6 +390,7 @@ public class GerritGlobalModule extends FactoryModule {
     bind(AnonymousUser.class);
 
     factory(AbandonOp.Factory.class);
+    factory(AccountValidator.Factory.class);
     factory(RefOperationValidators.Factory.class);
     factory(OnSubmitValidators.Factory.class);
     factory(MergeValidators.Factory.class);

gerrit-server/src/main/java/com/google/gerrit/server/git/MergeOp.java

@@ -88,6 +88,7 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
@@ -430,7 +431,7 @@ public class MergeOp implements AutoCloseable {
       boolean checkSubmitRules,
       SubmitInput submitInput,
       boolean dryrun)
-      throws OrmException, RestApiException, UpdateException {
+      throws OrmException, RestApiException, UpdateException, IOException, ConfigInvalidException {
     this.submitInput = submitInput;
     this.accountsToNotify = notifyUtil.resolveAccounts(submitInput.notifyDetails);
     this.dryrun = dryrun;

gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java

@@ -84,7 +84,6 @@ import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.PatchSetUtil;
 import com.google.gerrit.server.Sequences;
 import com.google.gerrit.server.account.AccountResolver;
-import com.google.gerrit.server.account.Accounts;
 import com.google.gerrit.server.account.AccountsUpdate;
 import com.google.gerrit.server.change.ChangeInserter;
 import com.google.gerrit.server.change.SetHashtagsOp;
@@ -155,6 +154,7 @@ import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.Constants;
@@ -301,7 +301,6 @@ public class ReceiveCommits {
   private final Sequences seq;
   private final Provider<InternalChangeQuery> queryProvider;
   private final ChangeNotes.Factory notesFactory;
-  private final Accounts accounts;
   private final AccountsUpdate.Server accountsUpdate;
   private final AccountResolver accountResolver;
   private final PermissionBackend permissionBackend;
@@ -376,7 +375,6 @@ public class ReceiveCommits {
       Sequences seq,
       Provider<InternalChangeQuery> queryProvider,
       ChangeNotes.Factory notesFactory,
-      Accounts accounts,
       AccountsUpdate.Server accountsUpdate,
       AccountResolver accountResolver,
       PermissionBackend permissionBackend,
@@ -416,7 +414,6 @@ public class ReceiveCommits {
     this.seq = seq;
     this.queryProvider = queryProvider;
     this.notesFactory = notesFactory;
-    this.accounts = accounts;
     this.accountsUpdate = accountsUpdate;
     this.accountResolver = accountResolver;
     this.permissionBackend = permissionBackend;
@@ -815,7 +812,11 @@ public class ReceiveCommits {
       } catch (ResourceConflictException e) {
         addMessage(e.getMessage());
         reject(magicBranchCmd, "conflict");
-      } catch (RestApiException | OrmException | UpdateException e) {
+      } catch (RestApiException
+          | OrmException
+          | UpdateException
+          | IOException
+          | ConfigInvalidException e) {
         logError("Error submitting changes to " + project.getName(), e);
         reject(magicBranchCmd, "error during submit");
       }
@@ -2258,7 +2259,7 @@ public class ReceiveCommits {
   }
 
   private void submit(Collection<CreateRequest> create, Collection<ReplaceRequest> replace)
-      throws OrmException, RestApiException, UpdateException {
+      throws OrmException, RestApiException, UpdateException, IOException, ConfigInvalidException {
     Map<ObjectId, Change> bySha = Maps.newHashMapWithExpectedSize(create.size() + replace.size());
     for (CreateRequest r : create) {
       checkNotNull(r.change, "cannot submit new change %s; op may not have run", r.changeId);
@@ -2783,13 +2784,22 @@ public class ReceiveCommits {
 
         if (defaultName && user.hasEmailAddress(c.getCommitterIdent().getEmailAddress())) {
           try {
-            Account a = accounts.get(db, user.getAccountId());
-            if (a != null && Strings.isNullOrEmpty(a.getFullName())) {
-              a.setFullName(c.getCommitterIdent().getName());
-              accountsUpdate.create().update(db, a);
-              user.getAccount().setFullName(a.getFullName());
+            String committerName = c.getCommitterIdent().getName();
+            Account account =
+                accountsUpdate
+                    .create()
+                    .update(
+                        db,
+                        user.getAccountId(),
+                        a -> {
+                          if (Strings.isNullOrEmpty(a.getFullName())) {
+                            a.setFullName(committerName);
+                          }
+                        });
+            if (account != null && Strings.isNullOrEmpty(account.getFullName())) {
+              user.getAccount().setFullName(account.getFullName());
             }
-          } catch (OrmException e) {
+          } catch (OrmException | IOException | ConfigInvalidException e) {
             logWarn("Cannot default full_name", e);
           } finally {
             defaultName = false;

gerrit-server/src/main/java/com/google/gerrit/server/git/VersionedMetaData.java

@@ -75,6 +75,7 @@ public abstract class VersionedMetaData {
   }
 
   protected RevCommit revision;
+  protected RevWalk rw;
   protected ObjectReader reader;
   protected ObjectInserter inserter;
   protected DirCache newTree;
@@ -153,11 +154,13 @@ public abstract class VersionedMetaData {
    * @throws ConfigInvalidException
    */
   public void load(RevWalk walk, ObjectId id) throws IOException, ConfigInvalidException {
+    this.rw = walk;
     this.reader = walk.getObjectReader();
     try {
       revision = id != null ? walk.parseCommit(id) : null;
       onLoad();
     } finally {
+      walk = null;
       reader = null;
     }
   }

gerrit-server/src/main/java/com/google/gerrit/server/git/validators/CommitValidators.java

@@ -31,6 +31,7 @@ import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.RefNames;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.account.AccountConfig;
 import com.google.gerrit.server.account.WatchConfig;
 import com.google.gerrit.server.account.externalids.ExternalIdsConsistencyChecker;
 import com.google.gerrit.server.config.AllUsersName;
@@ -57,9 +58,11 @@ import java.net.URL;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 import java.util.regex.Pattern;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.notes.NoteMap;
@@ -67,6 +70,7 @@ import org.eclipse.jgit.revwalk.FooterKey;
 import org.eclipse.jgit.revwalk.FooterLine;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.treewalk.TreeWalk;
 import org.eclipse.jgit.util.SystemReader;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -120,7 +124,8 @@ public class CommitValidators {
               new ConfigValidator(refctl, rw, allUsers),
               new BannedCommitsValidator(rejectCommits),
               new PluginCommitValidationListener(pluginValidators),
-              new ExternalIdUpdateListener(allUsers, externalIdsConsistencyChecker)));
+              new ExternalIdUpdateListener(allUsers, externalIdsConsistencyChecker),
+              new AccountValidator(allUsers)));
     }
 
     public CommitValidators forGerritCommits(
@@ -135,7 +140,8 @@ public class CommitValidators {
               new ChangeIdValidator(refctl, canonicalWebUrl, installCommitMsgHookCommand, sshInfo),
               new ConfigValidator(refctl, rw, allUsers),
               new PluginCommitValidationListener(pluginValidators),
-              new ExternalIdUpdateListener(allUsers, externalIdsConsistencyChecker)));
+              new ExternalIdUpdateListener(allUsers, externalIdsConsistencyChecker),
+              new AccountValidator(allUsers)));
     }
 
     public CommitValidators forMergedCommits(PermissionBackend.ForRef perm, RefControl refControl) {
@@ -679,6 +685,60 @@ public class CommitValidators {
     }
   }
 
+  /** Rejects updates to 'account.config' in user branches. */
+  public static class AccountValidator implements CommitValidationListener {
+    private final AllUsersName allUsers;
+
+    public AccountValidator(AllUsersName allUsers) {
+      this.allUsers = allUsers;
+    }
+
+    @Override
+    public List<CommitValidationMessage> onCommitReceived(CommitReceivedEvent receiveEvent)
+        throws CommitValidationException {
+      if (!allUsers.equals(receiveEvent.project.getNameKey())) {
+        return Collections.emptyList();
+      }
+
+      if (receiveEvent.command.getRefName().startsWith(MagicBranch.NEW_CHANGE)) {
+        // no validation on push for review, will be checked on submit by
+        // MergeValidators.AccountValidator
+        return Collections.emptyList();
+      }
+
+      Account.Id accountId = Account.Id.fromRef(receiveEvent.refName);
+      if (accountId == null) {
+        return Collections.emptyList();
+      }
+
+      try {
+        ObjectId newBlobId = getAccountConfigBlobId(receiveEvent.revWalk, receiveEvent.commit);
+
+        ObjectId oldId = receiveEvent.command.getOldId();
+        ObjectId oldBlobId =
+            !ObjectId.zeroId().equals(oldId)
+                ? getAccountConfigBlobId(receiveEvent.revWalk, oldId)
+                : null;
+        if (!Objects.equals(oldBlobId, newBlobId)) {
+          throw new CommitValidationException("account update not allowed");
+        }
+      } catch (IOException e) {
+        String m = String.format("Validating update for account %s failed", accountId.get());
+        log.error(m, e);
+        throw new CommitValidationException(m, e);
+      }
+      return Collections.emptyList();
+    }
+
+    private ObjectId getAccountConfigBlobId(RevWalk rw, ObjectId id) throws IOException {
+      RevCommit commit = rw.parseCommit(id);
+      try (TreeWalk tw =
+          TreeWalk.forPath(rw.getObjectReader(), AccountConfig.ACCOUNT_CONFIG, commit.getTree())) {
+        return tw != null ? tw.getObjectId(0) : null;
+      }
+    }
+  }
+
   private static CommitValidationMessage invalidEmail(
       RevCommit c,
       String type,

gerrit-server/src/main/java/com/google/gerrit/server/git/validators/MergeValidators.java

@@ -20,12 +20,16 @@ import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.extensions.registration.DynamicMap.Entry;
 import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.extensions.restapi.AuthException;
+import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.Branch;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.client.RefNames;
+import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.account.AccountConfig;
 import com.google.gerrit.server.config.AllProjectsName;
+import com.google.gerrit.server.config.AllUsersName;
 import com.google.gerrit.server.config.PluginConfig;
 import com.google.gerrit.server.config.ProjectConfigEntry;
 import com.google.gerrit.server.git.CodeReviewCommit;
@@ -35,7 +39,10 @@ import com.google.gerrit.server.permissions.PermissionBackend;
 import com.google.gerrit.server.permissions.PermissionBackendException;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.project.ProjectState;
+import com.google.gerrit.server.query.change.ChangeData;
+import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
+import com.google.inject.Provider;
 import java.io.IOException;
 import java.util.List;
 import org.eclipse.jgit.errors.ConfigInvalidException;
@@ -48,6 +55,7 @@ public class MergeValidators {
 
   private final DynamicSet<MergeValidationListener> mergeValidationListeners;
   private final ProjectConfigValidator.Factory projectConfigValidatorFactory;
+  private final AccountValidator.Factory accountValidatorFactory;
 
   public interface Factory {
     MergeValidators create();
@@ -56,9 +64,11 @@ public class MergeValidators {
   @Inject
   MergeValidators(
       DynamicSet<MergeValidationListener> mergeValidationListeners,
-      ProjectConfigValidator.Factory projectConfigValidatorFactory) {
+      ProjectConfigValidator.Factory projectConfigValidatorFactory,
+      AccountValidator.Factory accountValidatorFactory) {
     this.mergeValidationListeners = mergeValidationListeners;
     this.projectConfigValidatorFactory = projectConfigValidatorFactory;
+    this.accountValidatorFactory = accountValidatorFactory;
   }
 
   public void validatePreMerge(
@@ -72,7 +82,8 @@ public class MergeValidators {
     List<MergeValidationListener> validators =
         ImmutableList.of(
             new PluginMergeValidationListener(mergeValidationListeners),
-            projectConfigValidatorFactory.create());
+            projectConfigValidatorFactory.create(),
+            accountValidatorFactory.create());
 
     for (MergeValidationListener validator : validators) {
       validator.onPreMerge(repo, commit, destProject, destBranch, patchSetId, caller);
@@ -210,4 +221,59 @@ public class MergeValidators {
       }
     }
   }
+
+  public static class AccountValidator implements MergeValidationListener {
+    public interface Factory {
+      AccountValidator create();
+    }
+
+    private final Provider<ReviewDb> dbProvider;
+    private final AllUsersName allUsersName;
+    private final ChangeData.Factory changeDataFactory;
+
+    @Inject
+    public AccountValidator(
+        Provider<ReviewDb> dbProvider,
+        AllUsersName allUsersName,
+        ChangeData.Factory changeDataFactory) {
+      this.dbProvider = dbProvider;
+      this.allUsersName = allUsersName;
+      this.changeDataFactory = changeDataFactory;
+    }
+
+    @Override
+    public void onPreMerge(
+        Repository repo,
+        CodeReviewCommit commit,
+        ProjectState destProject,
+        Branch.NameKey destBranch,
+        PatchSet.Id patchSetId,
+        IdentifiedUser caller)
+        throws MergeValidationException {
+      if (!allUsersName.equals(destProject.getProject().getNameKey())
+          || Account.Id.fromRef(destBranch.get()) == null) {
+        return;
+      }
+
+      if (commit.getParentCount() > 1) {
+        // for merge commits we cannot ensure that the 'account.config' file is not modified, since
+        // for merge commits file modifications that come in through the merge don't appear in the
+        // file list that is returned by ChangeData#currentFilePaths()
+        throw new MergeValidationException("cannot submit merge commit to user branch");
+      }
+
+      ChangeData cd =
+          changeDataFactory.create(
+              dbProvider.get(), destProject.getProject().getNameKey(), patchSetId.getParentKey());
+      try {
+        if (cd.currentFilePaths().contains(AccountConfig.ACCOUNT_CONFIG)) {
+          throw new MergeValidationException(
+              String.format("update of %s not allowed", AccountConfig.ACCOUNT_CONFIG));
+        }
+      } catch (OrmException e) {
+        log.error("Cannot validate account update", e);
+        throw new MergeValidationException("account validation unavailable");
+      }
+    }
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/group/AddMembers.java

@@ -52,6 +52,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class AddMembers implements RestModifyView<GroupResource, Input> {
@@ -115,7 +116,7 @@ public class AddMembers implements RestModifyView<GroupResource, Input> {
   @Override
   public List<AccountInfo> apply(GroupResource resource, Input input)
       throws AuthException, MethodNotAllowedException, UnprocessableEntityException, OrmException,
-          IOException {
+          IOException, ConfigInvalidException {
     AccountGroup internalGroup = resource.toAccountGroup();
     if (internalGroup == null) {
       throw new MethodNotAllowedException();
@@ -143,7 +144,8 @@ public class AddMembers implements RestModifyView<GroupResource, Input> {
   }
 
   Account findAccount(String nameOrEmailOrId)
-      throws AuthException, UnprocessableEntityException, OrmException, IOException {
+      throws AuthException, UnprocessableEntityException, OrmException, IOException,
+          ConfigInvalidException {
     try {
       return accounts.parse(nameOrEmailOrId).getAccount();
     } catch (UnprocessableEntityException e) {
@@ -235,7 +237,7 @@ public class AddMembers implements RestModifyView<GroupResource, Input> {
     @Override
     public AccountInfo apply(GroupResource resource, PutMember.Input input)
         throws AuthException, MethodNotAllowedException, ResourceNotFoundException, OrmException,
-            IOException {
+            IOException, ConfigInvalidException {
       AddMembers.Input in = new AddMembers.Input();
       in._oneMember = id;
       try {

gerrit-server/src/main/java/com/google/gerrit/server/group/CreateGroup.java

@@ -55,6 +55,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.PersonIdent;
 
@@ -115,7 +116,7 @@ public class CreateGroup implements RestModifyView<TopLevelResource, GroupInput>
   @Override
   public GroupInfo apply(TopLevelResource resource, GroupInput input)
       throws AuthException, BadRequestException, UnprocessableEntityException,
-          ResourceConflictException, OrmException, IOException {
+          ResourceConflictException, OrmException, IOException, ConfigInvalidException {
     if (input == null) {
       input = new GroupInput();
     }

gerrit-server/src/main/java/com/google/gerrit/server/group/DeleteMembers.java

@@ -38,6 +38,7 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class DeleteMembers implements RestModifyView<GroupResource, Input> {
@@ -64,7 +65,7 @@ public class DeleteMembers implements RestModifyView<GroupResource, Input> {
   @Override
   public Response<?> apply(GroupResource resource, Input input)
       throws AuthException, MethodNotAllowedException, UnprocessableEntityException, OrmException,
-          IOException {
+          IOException, ConfigInvalidException {
     AccountGroup internalGroup = resource.toAccountGroup();
     if (internalGroup == null) {
       throw new MethodNotAllowedException();
@@ -125,7 +126,7 @@ public class DeleteMembers implements RestModifyView<GroupResource, Input> {
     @Override
     public Response<?> apply(MemberResource resource, Input input)
         throws AuthException, MethodNotAllowedException, UnprocessableEntityException, OrmException,
-            IOException {
+            IOException, ConfigInvalidException {
       AddMembers.Input in = new AddMembers.Input();
       in._oneMember = resource.getMember().getAccountId().toString();
       return delete.get().apply(resource, in);

gerrit-server/src/main/java/com/google/gerrit/server/group/MembersCollection.java

@@ -32,6 +32,8 @@ import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
+import java.io.IOException;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 
 @Singleton
 public class MembersCollection
@@ -63,7 +65,8 @@ public class MembersCollection
 
   @Override
   public MemberResource parse(GroupResource parent, IdString id)
-      throws MethodNotAllowedException, AuthException, ResourceNotFoundException, OrmException {
+      throws MethodNotAllowedException, AuthException, ResourceNotFoundException, OrmException,
+          IOException, ConfigInvalidException {
     if (parent.toAccountGroup() == null) {
       throw new MethodNotAllowedException();
     }

gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java

@@ -732,7 +732,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> label(String name) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> label(String name)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     Set<Account.Id> accounts = null;
     AccountGroup.UUID group = null;
 
@@ -846,7 +847,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> starredby(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> starredby(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     return starredby(parseAccount(who));
   }
 
@@ -863,7 +865,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> watchedby(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> watchedby(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     Set<Account.Id> m = parseAccount(who);
     List<IsWatchedByPredicate> p = Lists.newArrayListWithCapacity(m.size());
 
@@ -887,7 +890,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> draftby(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> draftby(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     Set<Account.Id> m = parseAccount(who);
     List<Predicate<ChangeData>> p = Lists.newArrayListWithCapacity(m.size());
     for (Account.Id id : m) {
@@ -905,7 +909,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> visibleto(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> visibleto(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     if (isSelf(who)) {
       return is_visible();
     }
@@ -942,12 +947,14 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> o(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> o(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     return owner(who);
   }
 
   @Operator
-  public Predicate<ChangeData> owner(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> owner(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     return owner(parseAccount(who));
   }
 
@@ -960,7 +967,7 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   private Predicate<ChangeData> ownerDefaultField(String who)
-      throws QueryParseException, OrmException {
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     Set<Account.Id> accounts = parseAccount(who);
     if (accounts.size() > MAX_ACCOUNTS_PER_DEFAULT_FIELD) {
       return Predicate.any();
@@ -969,7 +976,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> assignee(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> assignee(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     return assignee(parseAccount(who));
   }
 
@@ -991,22 +999,24 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> r(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> r(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     return reviewer(who);
   }
 
   @Operator
-  public Predicate<ChangeData> reviewer(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> reviewer(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     return reviewer(who, false);
   }
 
   private Predicate<ChangeData> reviewerDefaultField(String who)
-      throws QueryParseException, OrmException {
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     return reviewer(who, true);
   }
 
   private Predicate<ChangeData> reviewer(String who, boolean forDefaultField)
-      throws QueryParseException, OrmException {
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     Predicate<ChangeData> byState =
         reviewerByState(who, ReviewerStateInternal.REVIEWER, forDefaultField);
     if (Objects.equals(byState, Predicate.<ChangeData>any())) {
@@ -1020,7 +1030,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> cc(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> cc(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     return reviewerByState(who, ReviewerStateInternal.CC, false);
   }
 
@@ -1073,7 +1084,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> commentby(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> commentby(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     return commentby(parseAccount(who));
   }
 
@@ -1086,7 +1098,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> from(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> from(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     Set<Account.Id> ownerIds = parseAccount(who);
     return Predicate.or(owner(ownerIds), commentby(ownerIds));
   }
@@ -1110,7 +1123,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
   }
 
   @Operator
-  public Predicate<ChangeData> reviewedby(String who) throws QueryParseException, OrmException {
+  public Predicate<ChangeData> reviewedby(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     return IsReviewedPredicate.create(parseAccount(who));
   }
 
@@ -1192,7 +1206,7 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
       if (!Objects.equals(p, Predicate.<ChangeData>any())) {
         predicates.add(p);
       }
-    } catch (OrmException | QueryParseException e) {
+    } catch (OrmException | IOException | ConfigInvalidException | QueryParseException e) {
       // Skip.
     }
     try {
@@ -1200,13 +1214,13 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
       if (!Objects.equals(p, Predicate.<ChangeData>any())) {
         predicates.add(p);
       }
-    } catch (OrmException | QueryParseException e) {
+    } catch (OrmException | IOException | ConfigInvalidException | QueryParseException e) {
       // Skip.
     }
     predicates.add(file(query));
     try {
       predicates.add(label(query));
-    } catch (OrmException | QueryParseException e) {
+    } catch (OrmException | IOException | ConfigInvalidException | QueryParseException e) {
       // Skip.
     }
     predicates.add(commit(query));
@@ -1245,7 +1259,8 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
     return Predicate.and(predicates);
   }
 
-  private Set<Account.Id> parseAccount(String who) throws QueryParseException, OrmException {
+  private Set<Account.Id> parseAccount(String who)
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     if (isSelf(who)) {
       return Collections.singleton(self());
     }
@@ -1291,7 +1306,7 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
 
   public Predicate<ChangeData> reviewerByState(
       String who, ReviewerStateInternal state, boolean forDefaultField)
-      throws QueryParseException, OrmException {
+      throws QueryParseException, OrmException, IOException, ConfigInvalidException {
     Predicate<ChangeData> reviewerByEmailPredicate = null;
     if (args.index.getSchema().hasField(ChangeField.REVIEWER_BY_EMAIL)) {
       Address address = Address.tryParse(who);

gerrit-server/src/main/java/com/google/gerrit/server/schema/SchemaVersion.java

@@ -35,7 +35,7 @@ import java.util.concurrent.TimeUnit;
 /** A version of the database schema. */
 public abstract class SchemaVersion {
   /** The current schema version. */
-  public static final Class<Schema_153> C = Schema_153.class;
+  public static final Class<Schema_154> C = Schema_154.class;
 
   public static int getBinaryVersion() {
     return guessVersion(C);

gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_146.java

@@ -20,6 +20,7 @@ import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.account.AccountsUpdate;
 import com.google.gerrit.server.config.AllUsersName;
+import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
@@ -88,7 +89,15 @@ public class Schema_146 extends SchemaVersion {
           rewriteUserBranch(repo, rw, oi, emptyTree, ref, e.getValue());
         } else {
           AccountsUpdate.createUserBranch(
-              repo, oi, serverIdent, serverIdent, e.getKey(), e.getValue());
+              repo,
+              allUsersName,
+              GitReferenceUpdated.DISABLED,
+              null,
+              oi,
+              serverIdent,
+              serverIdent,
+              e.getKey(),
+              e.getValue());
         }
       }
     } catch (IOException e) {

gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_147.java

@@ -22,6 +22,7 @@ import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.account.AccountsUpdate;
 import com.google.gerrit.server.config.AllUsersName;
+import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
@@ -68,7 +69,8 @@ public class Schema_147 extends SchemaVersion {
               .collect(toSet());
       accountIdsFromUserBranches.removeAll(accountIdsFromReviewDb);
       for (Account.Id accountId : accountIdsFromUserBranches) {
-        AccountsUpdate.deleteUserBranch(repo, serverIdent, accountId);
+        AccountsUpdate.deleteUserBranch(
+            repo, allUsersName, GitReferenceUpdated.DISABLED, null, serverIdent, accountId);
       }
     } catch (IOException e) {
       throw new OrmException("Failed to delete user branches for non-existing accounts.", e);

gerrit-server/src/main/java/com/google/gerrit/server/schema/Schema_154.java

@@ -0,0 +1,105 @@
+// Copyright (C) 2017 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.schema;
+
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.GerritPersonIdent;
+import com.google.gerrit.server.account.AccountConfig;
+import com.google.gerrit.server.config.AllUsersName;
+import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
+import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.git.MetaDataUpdate;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import java.io.IOException;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.HashSet;
+import java.util.Set;
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.lib.Repository;
+
+/** Migrate accounts to NoteDb. */
+public class Schema_154 extends SchemaVersion {
+  private final GitRepositoryManager repoManager;
+  private final AllUsersName allUsersName;
+  private final Provider<PersonIdent> serverIdent;
+
+  @Inject
+  Schema_154(
+      Provider<Schema_153> prior,
+      GitRepositoryManager repoManager,
+      AllUsersName allUsersName,
+      @GerritPersonIdent Provider<PersonIdent> serverIdent) {
+    super(prior);
+    this.repoManager = repoManager;
+    this.allUsersName = allUsersName;
+    this.serverIdent = serverIdent;
+  }
+
+  @Override
+  protected void migrateData(ReviewDb db, UpdateUI ui) throws OrmException, SQLException {
+    try {
+      try (Repository repo = repoManager.openRepository(allUsersName)) {
+        for (Account account : scanAccounts(db)) {
+          updateAccountInNoteDb(repo, account);
+        }
+      }
+    } catch (IOException | ConfigInvalidException e) {
+      throw new OrmException("Migrating accounts to NoteDb failed", e);
+    }
+  }
+
+  private Set<Account> scanAccounts(ReviewDb db) throws SQLException {
+    try (Statement stmt = newStatement(db);
+        ResultSet rs =
+            stmt.executeQuery(
+                "SELECT account_id,"
+                    + " registered_on,"
+                    + " full_name, "
+                    + " preferred_email,"
+                    + " status,"
+                    + " inactive"
+                    + " FROM accounts")) {
+      Set<Account> s = new HashSet<>();
+      while (rs.next()) {
+        Account a = new Account(new Account.Id(rs.getInt(1)), rs.getTimestamp(2));
+        a.setFullName(rs.getString(3));
+        a.setPreferredEmail(rs.getString(4));
+        a.setStatus(rs.getString(5));
+        a.setActive(rs.getString(6).equals("N"));
+        s.add(a);
+      }
+      return s;
+    }
+  }
+
+  private void updateAccountInNoteDb(Repository allUsersRepo, Account account)
+      throws IOException, ConfigInvalidException {
+    MetaDataUpdate md =
+        new MetaDataUpdate(GitReferenceUpdated.DISABLED, allUsersName, allUsersRepo);
+    PersonIdent ident = serverIdent.get();
+    md.getCommitBuilder().setAuthor(ident);
+    md.getCommitBuilder().setCommitter(ident);
+    AccountConfig accountConfig = new AccountConfig(null, account.getId());
+    accountConfig.load(allUsersRepo);
+    accountConfig.setAccount(account);
+    accountConfig.commit(md);
+  }
+}

gerrit-server/src/test/java/com/google/gerrit/server/query/account/AbstractQueryAccountsTest.java

@@ -33,14 +33,20 @@ import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.AnonymousUser;
 import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.account.AccountCache;
+import com.google.gerrit.server.account.AccountConfig;
 import com.google.gerrit.server.account.AccountManager;
 import com.google.gerrit.server.account.AccountState;
 import com.google.gerrit.server.account.Accounts;
 import com.google.gerrit.server.account.AccountsUpdate;
 import com.google.gerrit.server.account.AuthRequest;
 import com.google.gerrit.server.config.AllProjectsName;
+import com.google.gerrit.server.config.AllUsersName;
+import com.google.gerrit.server.extensions.events.GitReferenceUpdated;
+import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.git.MetaDataUpdate;
 import com.google.gerrit.server.schema.SchemaCreator;
 import com.google.gerrit.server.util.ManualRequestContext;
 import com.google.gerrit.server.util.OneOffRequestContext;
@@ -58,6 +64,8 @@ import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
 import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.lib.Repository;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Ignore;
@@ -82,6 +90,8 @@ public abstract class AbstractQueryAccountsTest extends GerritServerTests {
 
   @Inject protected GerritApi gApi;
 
+  @Inject @GerritPersonIdent Provider<PersonIdent> serverIdent;
+
   @Inject protected IdentifiedUser.GenericFactory userFactory;
 
   @Inject private Provider<AnonymousUser> anonymousUser;
@@ -98,6 +108,10 @@ public abstract class AbstractQueryAccountsTest extends GerritServerTests {
 
   @Inject protected AllProjectsName allProjects;
 
+  @Inject protected AllUsersName allUsers;
+
+  @Inject protected GitRepositoryManager repoManager;
+
   protected LifecycleManager lifecycle;
   protected Injector injector;
   protected ReviewDb db;
@@ -383,12 +397,25 @@ public abstract class AbstractQueryAccountsTest extends GerritServerTests {
   public void reindex() throws Exception {
     AccountInfo user1 = newAccountWithFullName("tester", "Test Usre");
 
-    // update account in the database so that account index is stale
+    // update account in ReviewDb without reindex so that account index is stale
     String newName = "Test User";
-    Account account = accounts.get(db, new Account.Id(user1._accountId));
+    Account.Id accountId = new Account.Id(user1._accountId);
+    Account account = accounts.get(db, accountId);
     account.setFullName(newName);
     db.accounts().update(ImmutableSet.of(account));
 
+    // update account in NoteDb without reindex so that account index is stale
+    try (Repository repo = repoManager.openRepository(allUsers)) {
+      MetaDataUpdate md = new MetaDataUpdate(GitReferenceUpdated.DISABLED, allUsers, repo);
+      PersonIdent ident = serverIdent.get();
+      md.getCommitBuilder().setAuthor(ident);
+      md.getCommitBuilder().setCommitter(ident);
+      AccountConfig accountConfig = new AccountConfig(null, accountId);
+      accountConfig.load(repo);
+      accountConfig.getAccount().setFullName(newName);
+      accountConfig.commit(md);
+    }
+
     assertQuery("name:" + quote(user1.name), user1);
     assertQuery("name:" + quote(newName));
 
@@ -469,11 +496,16 @@ public abstract class AbstractQueryAccountsTest extends GerritServerTests {
       if (email != null) {
         accountManager.link(id, AuthRequest.forEmail(email));
       }
-      Account a = accounts.get(db, id);
-      a.setFullName(fullName);
-      a.setPreferredEmail(email);
-      a.setActive(active);
-      accountsUpdate.create().update(db, a);
+      accountsUpdate
+          .create()
+          .update(
+              db,
+              id,
+              a -> {
+                a.setFullName(fullName);
+                a.setPreferredEmail(email);
+                a.setActive(active);
+              });
       return id;
     }
   }

gerrit-server/src/test/java/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java

@@ -208,13 +208,11 @@ public abstract class AbstractQueryChangesTest extends GerritServerTests {
     db = schemaFactory.open();
 
     userId = accountManager.authenticate(AuthRequest.forUser("user")).getAccountId();
-    Account userAccount = accounts.get(db, userId);
     String email = "user@example.com";
     externalIdsUpdate.create().insert(ExternalId.createEmail(userId, email));
-    userAccount.setPreferredEmail(email);
-    accountsUpdate.create().update(db, userAccount);
+    accountsUpdate.create().update(db, userId, a -> a.setPreferredEmail(email));
     user = userFactory.create(userId);
-    requestContext.setContext(newRequestContext(userAccount.getId()));
+    requestContext.setContext(newRequestContext(userId));
   }
 
   protected RequestContext newRequestContext(Account.Id requestUserId) {
@@ -2340,11 +2338,16 @@ public abstract class AbstractQueryChangesTest extends GerritServerTests {
       if (email != null) {
         accountManager.link(id, AuthRequest.forEmail(email));
       }
-      Account a = accounts.get(db, id);
-      a.setFullName(fullName);
-      a.setPreferredEmail(email);
-      a.setActive(active);
-      accountsUpdate.create().update(db, a);
+      accountsUpdate
+          .create()
+          .update(
+              db,
+              id,
+              a -> {
+                a.setFullName(fullName);
+                a.setPreferredEmail(email);
+                a.setActive(active);
+              });
       return id;
     }
   }

gerrit-server/src/test/java/com/google/gerrit/server/query/group/AbstractQueryGroupsTest.java

@@ -319,11 +319,16 @@ public abstract class AbstractQueryGroupsTest extends GerritServerTests {
       if (email != null) {
         accountManager.link(id, AuthRequest.forEmail(email));
       }
-      Account a = accounts.get(db, id);
-      a.setFullName(fullName);
-      a.setPreferredEmail(email);
-      a.setActive(active);
-      accountsUpdate.create().update(db, a);
+      accountsUpdate
+          .create()
+          .update(
+              db,
+              id,
+              a -> {
+                a.setFullName(fullName);
+                a.setPreferredEmail(email);
+                a.setActive(active);
+              });
       return id;
     }
   }

gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/CreateGroupCommand.java

@@ -37,6 +37,7 @@ import com.google.inject.Inject;
 import java.io.IOException;
 import java.util.HashSet;
 import java.util.Set;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.kohsuke.args4j.Argument;
 import org.kohsuke.args4j.Option;
 
@@ -103,7 +104,7 @@ final class CreateGroupCommand extends SshCommand {
   @Inject private AddIncludedGroups addIncludedGroups;
 
   @Override
-  protected void run() throws Failure, OrmException, IOException {
+  protected void run() throws Failure, OrmException, IOException, ConfigInvalidException {
     try {
       GroupResource rsrc = createGroup();
 
@@ -119,7 +120,8 @@ final class CreateGroupCommand extends SshCommand {
     }
   }
 
-  private GroupResource createGroup() throws RestApiException, OrmException, IOException {
+  private GroupResource createGroup()
+      throws RestApiException, OrmException, IOException, ConfigInvalidException {
     GroupInput input = new GroupInput();
     input.description = groupDescription;
     input.visibleToAll = visibleToAll;
@@ -132,7 +134,8 @@ final class CreateGroupCommand extends SshCommand {
     return groups.parse(TopLevelResource.INSTANCE, IdString.fromUrl(group.id));
   }
 
-  private void addMembers(GroupResource rsrc) throws RestApiException, OrmException, IOException {
+  private void addMembers(GroupResource rsrc)
+      throws RestApiException, OrmException, IOException, ConfigInvalidException {
     AddMembers.Input input =
         AddMembers.Input.fromMembers(
             initialMembers.stream().map(Object::toString).collect(toList()));

gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/LsUserRefs.java

@@ -35,6 +35,7 @@ import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import java.io.IOException;
 import java.util.Map;
+import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
@@ -79,7 +80,7 @@ public class LsUserRefs extends SshCommand {
     Account userAccount;
     try {
       userAccount = accountResolver.find(db, userName);
-    } catch (OrmException e) {
+    } catch (OrmException | IOException | ConfigInvalidException e) {
       throw die(e);
     }
     if (userAccount == null) {

gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/SetAccountCommand.java

@@ -292,7 +292,8 @@ final class SetAccountCommand extends SshCommand {
   }
 
   private void putPreferred(String email)
-      throws RestApiException, OrmException, IOException, PermissionBackendException {
+      throws RestApiException, OrmException, IOException, PermissionBackendException,
+          ConfigInvalidException {
     for (EmailInfo e : getEmails.apply(rsrc)) {
       if (e.email.equals(email)) {
         putPreferred.apply(new AccountResource.Email(user, email), null);