diff --git a/java/com/google/gerrit/pgm/init/InitAdminUser.java b/java/com/google/gerrit/pgm/init/InitAdminUser.java
index f12fa50..4b435de 100644
--- a/java/com/google/gerrit/pgm/init/InitAdminUser.java
+++ b/java/com/google/gerrit/pgm/init/InitAdminUser.java
@@ -110,7 +110,7 @@
       if (!accounts.hasAnyAccount()) {
         ui.header("Gerrit Administrator");
         if (ui.yesno(true, "Create administrator user")) {
-          Account.Id id = new Account.Id(sequencesOnInit.nextAccountId(db));
+          Account.Id id = new Account.Id(sequencesOnInit.nextAccountId());
           String username = ui.readString("admin", "username");
           String name = ui.readString("Administrator", "name");
           String httpPassword = ui.readString("secret", "HTTP password");
diff --git a/java/com/google/gerrit/pgm/init/api/SequencesOnInit.java b/java/com/google/gerrit/pgm/init/api/SequencesOnInit.java
index c9c3a64..1716a3c 100644
--- a/java/com/google/gerrit/pgm/init/api/SequencesOnInit.java
+++ b/java/com/google/gerrit/pgm/init/api/SequencesOnInit.java
@@ -35,16 +35,14 @@
     this.allUsersName = allUsersName;
   }
 
-  public int nextAccountId(ReviewDb db) throws OrmException {
-    @SuppressWarnings("deprecation")
-    RepoSequence.Seed accountSeed = db::nextAccountId;
+  public int nextAccountId() throws OrmException {
     RepoSequence accountSeq =
         new RepoSequence(
             repoManager,
             GitReferenceUpdated.DISABLED,
             new Project.NameKey(allUsersName.get()),
             Sequences.NAME_ACCOUNTS,
-            accountSeed,
+            () -> ReviewDb.FIRST_ACCOUNT_ID,
             1);
     return accountSeq.next();
   }
diff --git a/java/com/google/gerrit/reviewdb/server/ReviewDb.java b/java/com/google/gerrit/reviewdb/server/ReviewDb.java
index 8e4292c..6668727 100644
--- a/java/com/google/gerrit/reviewdb/server/ReviewDb.java
+++ b/java/com/google/gerrit/reviewdb/server/ReviewDb.java
@@ -14,7 +14,6 @@
 
 package com.google.gerrit.reviewdb.server;
 
-import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.AccountGroup;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gwtorm.server.OrmException;
@@ -28,7 +27,6 @@
  * <p>Root entities that are at the top level of some important data graph:
  *
  * <ul>
- *   <li>{@link Account}: Per-user account registration, preferences, identity.
  *   <li>{@link Change}: All review information about a single proposed change.
  * </ul>
  */
@@ -91,15 +89,6 @@
 
   int FIRST_ACCOUNT_ID = 1000000;
 
-  /**
-   * Next unique id for a {@link Account}.
-   *
-   * @deprecated use {@link com.google.gerrit.server.Sequences#nextAccountId()}.
-   */
-  @Sequence(startWith = FIRST_ACCOUNT_ID)
-  @Deprecated
-  int nextAccountId() throws OrmException;
-
   int FIRST_GROUP_ID = 1;
 
   /** Next unique id for a {@link AccountGroup}. */
diff --git a/java/com/google/gerrit/reviewdb/server/ReviewDbWrapper.java b/java/com/google/gerrit/reviewdb/server/ReviewDbWrapper.java
index 202729e..27a4e29 100644
--- a/java/com/google/gerrit/reviewdb/server/ReviewDbWrapper.java
+++ b/java/com/google/gerrit/reviewdb/server/ReviewDbWrapper.java
@@ -136,12 +136,6 @@
 
   @Override
   @SuppressWarnings("deprecation")
-  public int nextAccountId() throws OrmException {
-    return delegate.nextAccountId();
-  }
-
-  @Override
-  @SuppressWarnings("deprecation")
   public int nextAccountGroupId() throws OrmException {
     return delegate.nextAccountGroupId();
   }
diff --git a/java/com/google/gerrit/server/git/receive/ReceiveCommits.java b/java/com/google/gerrit/server/git/receive/ReceiveCommits.java
index b23fe71..a3b094a 100644
--- a/java/com/google/gerrit/server/git/receive/ReceiveCommits.java
+++ b/java/com/google/gerrit/server/git/receive/ReceiveCommits.java
@@ -2727,10 +2727,13 @@
 
     /** prints a warning if the new PS has the same tree as the previous commit. */
     private void sameTreeWarning() throws IOException {
-      RevCommit newCommit = receivePack.getRevWalk().parseCommit(newCommitId);
+      RevWalk rw = receivePack.getRevWalk();
+      RevCommit newCommit = rw.parseCommit(newCommitId);
       RevCommit priorCommit = revisions.inverse().get(priorPatchSet);
 
       if (newCommit.getTree().equals(priorCommit.getTree())) {
+        rw.parseBody(newCommit);
+        rw.parseBody(priorCommit);
         boolean messageEq =
             Objects.equals(newCommit.getFullMessage(), priorCommit.getFullMessage());
         boolean parentsEq = parentsEqual(newCommit, priorCommit);
diff --git a/java/com/google/gerrit/server/schema/Schema_155.java b/java/com/google/gerrit/server/schema/Schema_155.java
index 812d7a6..e9372a5 100644
--- a/java/com/google/gerrit/server/schema/Schema_155.java
+++ b/java/com/google/gerrit/server/schema/Schema_155.java
@@ -40,15 +40,13 @@
 
   @Override
   protected void migrateData(ReviewDb db, UpdateUI ui) throws OrmException, SQLException {
-    @SuppressWarnings("deprecation")
-    RepoSequence.Seed accountSeed = db::nextAccountId;
     RepoSequence accountSeq =
         new RepoSequence(
             repoManager,
             GitReferenceUpdated.DISABLED,
             allUsersName,
             Sequences.NAME_ACCOUNTS,
-            accountSeed,
+            () -> ReviewDb.FIRST_ACCOUNT_ID,
             1);
 
     // consume one account ID to ensure that the account sequence is initialized in NoteDb
diff --git a/java/com/google/gerrit/testing/DisabledReviewDb.java b/java/com/google/gerrit/testing/DisabledReviewDb.java
index 2bf95b0..037c452 100644
--- a/java/com/google/gerrit/testing/DisabledReviewDb.java
+++ b/java/com/google/gerrit/testing/DisabledReviewDb.java
@@ -95,11 +95,6 @@
   }
 
   @Override
-  public int nextAccountId() {
-    throw new Disabled();
-  }
-
-  @Override
   public int nextAccountGroupId() {
     throw new Disabled();
   }
diff --git a/javatests/com/google/gerrit/acceptance/git/AbstractPushForReview.java b/javatests/com/google/gerrit/acceptance/git/AbstractPushForReview.java
index 228784b..5e82f84 100644
--- a/javatests/com/google/gerrit/acceptance/git/AbstractPushForReview.java
+++ b/javatests/com/google/gerrit/acceptance/git/AbstractPushForReview.java
@@ -1464,14 +1464,7 @@
 
   @Test
   public void pushSameCommitTwice() throws Exception {
-    try (ProjectConfigUpdate u = updateProject(project)) {
-      u.getConfig()
-          .getProject()
-          .setBooleanConfig(
-              BooleanProjectConfig.CREATE_NEW_CHANGE_FOR_ALL_NOT_IN_TARGET,
-              InheritableBoolean.TRUE);
-      u.save();
-    }
+    enableCreateNewChangeForAllNotInTarget();
 
     PushOneCommit push =
         pushFactory.create(
@@ -1493,14 +1486,7 @@
 
   @Test
   public void pushSameCommitTwiceWhenIndexFailed() throws Exception {
-    try (ProjectConfigUpdate u = updateProject(project)) {
-      u.getConfig()
-          .getProject()
-          .setBooleanConfig(
-              BooleanProjectConfig.CREATE_NEW_CHANGE_FOR_ALL_NOT_IN_TARGET,
-              InheritableBoolean.TRUE);
-      u.save();
-    }
+    enableCreateNewChangeForAllNotInTarget();
 
     PushOneCommit push =
         pushFactory.create(
@@ -2356,6 +2342,113 @@
     assertPushOk(pr, "refs/heads/permitted");
   }
 
+  @Test
+  public void pushCommitsWithSameTreeNoChanges() throws Exception {
+    RevCommit c =
+        testRepo
+            .commit()
+            .message("Foo")
+            .parent(getHead(testRepo.getRepository()))
+            .insertChangeId()
+            .create();
+    testRepo.reset(c);
+
+    String r = "refs/for/master";
+    PushResult pr = pushHead(testRepo, r, false);
+    assertPushOk(pr, r);
+
+    RevCommit amended = testRepo.amend(c).create();
+    testRepo.reset(amended);
+
+    pr = pushHead(testRepo, r, false);
+    assertPushOk(pr, r);
+    assertThat(pr.getMessages())
+        .contains(
+            "warning: no changes between prior commit "
+                + c.abbreviate(7).name()
+                + " and new commit "
+                + amended.abbreviate(7).name());
+  }
+
+  @Test
+  public void pushCommitsWithSameTreeNoFilesChangedMessageUpdated() throws Exception {
+    RevCommit c =
+        testRepo
+            .commit()
+            .message("Foo")
+            .parent(getHead(testRepo.getRepository()))
+            .insertChangeId()
+            .create();
+    String id = GitUtil.getChangeId(testRepo, c).get();
+    testRepo.reset(c);
+
+    String r = "refs/for/master";
+    PushResult pr = pushHead(testRepo, r, false);
+    assertPushOk(pr, r);
+
+    RevCommit amended =
+        testRepo.amend(c).message("Foo Bar").insertChangeId(id.substring(1)).create();
+    testRepo.reset(amended);
+
+    pr = pushHead(testRepo, r, false);
+    assertPushOk(pr, r);
+    assertThat(pr.getMessages())
+        .contains(
+            "warning: " + amended.abbreviate(7).name() + ": no files changed, message updated");
+  }
+
+  @Test
+  public void pushCommitsWithSameTreeNoFilesChangedAuthorChanged() throws Exception {
+    RevCommit c =
+        testRepo
+            .commit()
+            .message("Foo")
+            .parent(getHead(testRepo.getRepository()))
+            .insertChangeId()
+            .create();
+    testRepo.reset(c);
+
+    String r = "refs/for/master";
+    PushResult pr = pushHead(testRepo, r, false);
+    assertPushOk(pr, r);
+
+    RevCommit amended = testRepo.amend(c).author(user.getIdent()).create();
+    testRepo.reset(amended);
+
+    pr = pushHead(testRepo, r, false);
+    assertPushOk(pr, r);
+    assertThat(pr.getMessages())
+        .contains(
+            "warning: " + amended.abbreviate(7).name() + ": no files changed, author changed");
+  }
+
+  @Test
+  public void pushCommitsWithSameTreeNoFilesChangedWasRebased() throws Exception {
+    RevCommit head = getHead(testRepo.getRepository());
+    RevCommit c = testRepo.commit().message("Foo").parent(head).insertChangeId().create();
+    testRepo.reset(c);
+
+    String r = "refs/for/master";
+    PushResult pr = pushHead(testRepo, r, false);
+    assertPushOk(pr, r);
+
+    testRepo.reset(head);
+    RevCommit newBase = testRepo.commit().message("Base").parent(head).insertChangeId().create();
+    testRepo.reset(newBase);
+
+    pr = pushHead(testRepo, r, false);
+    assertPushOk(pr, r);
+
+    testRepo.reset(c);
+    RevCommit amended = testRepo.amend(c).parent(newBase).create();
+    testRepo.reset(amended);
+
+    pr = pushHead(testRepo, r, false);
+    assertPushOk(pr, r);
+    assertThat(pr.getMessages())
+        .contains("warning: " + amended.abbreviate(7).name() + ": no files changed, was rebased");
+  }
+
   private DraftInput newDraft(String path, int line, String message) {
     DraftInput d = new DraftInput();
     d.path = path;