Merge branch 'stable-3.8' into stable-3.9

* stable-3.8:
  Revert urelated changes to external_plugin_deps.bzl
  Fix starred changes clash after repo import from another site
  Resolve draft comment reference ambiguity for imported changes
  Fix DereferenceWithNullBranch bug pattern flagged by error prone
  Expose change's serverid in Change class
  Make ChangeNumberBitmapMaskAlgorithm a NOOP for local serverId
  Set version to 3.7.9-SNAPSHOT
  Set version to 3.7.8

Release-Notes: skip
Forward-Compatible: checked
Change-Id: Id634dd61b4a3de41d8cb3fdd72706d52a823f094

21 files changed, 268 insertions, 78 deletions

diff --git a/java/com/google/gerrit/entities/Change.java b/java/com/google/gerrit/entities/Change.java
index 56fb748e1d..fad3aa84ab 100644
--- a/java/com/google/gerrit/entities/Change.java
+++ b/java/com/google/gerrit/entities/Change.java
@@ -433,6 +433,9 @@ public final class Change {
   /** Locally assigned unique identifier of the change */
   private Id changeId;
 
+  /** ServerId of the Gerrit instance that has created the change */
+  private String serverId;
+
   /** Globally assigned unique identifier of the change */
   private Key changeKey;
 
@@ -530,6 +533,22 @@ public final class Change {
     return changeId;
   }
 
+  /**
+   * Set the serverId of the Gerrit instance that created the change. It can be set to null for
+   * testing purposes in the protobuf converter tests.
+   */
+  public void setServerId(@Nullable String serverId) {
+    this.serverId = serverId;
+  }
+
+  /**
+   * ServerId of the Gerrit instance that created the change. It could be null when the change is
+   * not fetched from NoteDb but obtained through protobuf deserialisation.
+   */
+  public @Nullable String getServerId() {
+    return serverId;
+  }
+
   /** 32 bit integer identity for a change. */
   public int getChangeId() {
     return changeId.get();
diff --git a/java/com/google/gerrit/extensions/common/ChangeInfo.java b/java/com/google/gerrit/extensions/common/ChangeInfo.java
index a2e2e8ffa9..69160e96ab 100644
--- a/java/com/google/gerrit/extensions/common/ChangeInfo.java
+++ b/java/com/google/gerrit/extensions/common/ChangeInfo.java
@@ -102,6 +102,7 @@ public class ChangeInfo {
   public Boolean containsGitConflicts;
 
   public Integer _number;
+  public Integer _virtualIdNumber;
 
   public AccountInfo owner;
 
diff --git a/java/com/google/gerrit/lucene/LuceneChangeIndex.java b/java/com/google/gerrit/lucene/LuceneChangeIndex.java
index 6718e368ed..990476ccf0 100644
--- a/java/com/google/gerrit/lucene/LuceneChangeIndex.java
+++ b/java/com/google/gerrit/lucene/LuceneChangeIndex.java
@@ -113,7 +113,7 @@ public class LuceneChangeIndex implements ChangeIndex {
   private static final String CHANGE_FIELD = ChangeField.CHANGE_SPEC.getName();
 
   static Term idTerm(ChangeData cd) {
-    return idTerm(cd.getVirtualId());
+    return idTerm(cd.virtualId());
   }
 
   static Term idTerm(Change.Id id) {
@@ -544,7 +544,13 @@ public class LuceneChangeIndex implements ChangeIndex {
     IndexableField cb = Iterables.getFirst(doc.get(CHANGE_FIELD), null);
     if (cb != null) {
       BytesRef proto = cb.binaryValue();
-      cd = changeDataFactory.create(parseProtoFrom(proto, ChangeProtoConverter.INSTANCE));
+      // pass the id field value (which is the change virtual id for the imported changes) when
+      // available
+      IndexableField f = Iterables.getFirst(doc.get(idFieldName), null);
+      cd =
+          changeDataFactory.create(
+              parseProtoFrom(proto, ChangeProtoConverter.INSTANCE),
+              f != null ? Change.id(Integer.valueOf(f.stringValue())) : null);
     } else {
       IndexableField f = Iterables.getFirst(doc.get(idFieldName), null);
 
diff --git a/java/com/google/gerrit/server/CommentsUtil.java b/java/com/google/gerrit/server/CommentsUtil.java
index 9d5d46aea6..bddd86af8c 100644
--- a/java/com/google/gerrit/server/CommentsUtil.java
+++ b/java/com/google/gerrit/server/CommentsUtil.java
@@ -24,6 +24,7 @@ import com.google.common.collect.ComparisonChain;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Ordering;
 import com.google.gerrit.common.Nullable;
+import com.google.gerrit.entities.Account;
 import com.google.gerrit.entities.Change;
 import com.google.gerrit.entities.ChangeMessage;
 import com.google.gerrit.entities.Comment;
@@ -31,10 +32,12 @@ import com.google.gerrit.entities.HumanComment;
 import com.google.gerrit.entities.Patch;
 import com.google.gerrit.entities.PatchSet;
 import com.google.gerrit.entities.Project;
+import com.google.gerrit.entities.RefNames;
 import com.google.gerrit.entities.RobotComment;
 import com.google.gerrit.exceptions.StorageException;
 import com.google.gerrit.extensions.client.Side;
 import com.google.gerrit.extensions.common.CommentInfo;
+import com.google.gerrit.server.config.AllUsersName;
 import com.google.gerrit.server.config.GerritServerId;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.notedb.ChangeNotes;
@@ -43,6 +46,7 @@ import com.google.gerrit.server.patch.DiffNotAvailableException;
 import com.google.gerrit.server.patch.DiffOperations;
 import com.google.gerrit.server.patch.DiffOptions;
 import com.google.gerrit.server.patch.filediff.FileDiffOutput;
+import com.google.gerrit.server.query.change.ChangeNumberVirtualIdAlgorithm;
 import com.google.gerrit.server.update.ChangeContext;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
@@ -55,6 +59,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 
@@ -111,16 +116,22 @@ public class CommentsUtil {
 
   private final DiffOperations diffOperations;
   private final GitRepositoryManager repoManager;
+  private final AllUsersName allUsers;
   private final String serverId;
+  private final ChangeNumberVirtualIdAlgorithm virtualIdAlgorithm;
 
   @Inject
   CommentsUtil(
       DiffOperations diffOperations,
       GitRepositoryManager repoManager,
-      @GerritServerId String serverId) {
+      AllUsersName allUsers,
+      @GerritServerId String serverId,
+      @Nullable ChangeNumberVirtualIdAlgorithm virtualIdAlgorithm) {
     this.diffOperations = diffOperations;
     this.repoManager = repoManager;
+    this.allUsers = allUsers;
     this.serverId = serverId;
+    this.virtualIdAlgorithm = virtualIdAlgorithm;
   }
 
   public HumanComment newHumanComment(
@@ -311,6 +322,17 @@ public class CommentsUtil {
         .collect(toList());
   }
 
+  public List<HumanComment> draftByPatchSetAuthor(
+      PatchSet.Id psId, Account.Id author, ChangeNotes notes) {
+    return commentsOnPatchSet(notes.load().getDraftComments(author, getVirtualId(notes)), psId);
+  }
+
+  public List<HumanComment> draftByChangeAuthor(ChangeNotes notes, Account.Id author) {
+    List<HumanComment> comments = new ArrayList<>();
+    comments.addAll(notes.getDraftComments(author, getVirtualId(notes)));
+    return sort(comments);
+  }
+
   public void putHumanComments(
       ChangeUpdate update, Comment.Status status, Iterable<HumanComment> comments) {
     for (HumanComment c : comments) {
@@ -425,8 +447,36 @@ public class CommentsUtil {
     }
   }
 
+  /**
+   * Get NoteDb draft refs for a change.
+   *
+   * <p>This is just a simple ref scan, so the results may potentially include refs for zombie draft
+   * comments. A zombie draft is one which has been published but the write to delete the draft ref
+   * from All-Users failed.
+   *
+   * @param changeId change ID.
+   * @return raw refs from All-Users repo.
+   */
+  public Collection<Ref> getDraftRefs(Change.Id changeId) {
+    try (Repository repo = repoManager.openRepository(allUsers)) {
+      return getDraftRefs(repo, changeId);
+    } catch (IOException e) {
+      throw new StorageException(e);
+    }
+  }
+
+  private Collection<Ref> getDraftRefs(Repository repo, Change.Id virtualId) throws IOException {
+    return repo.getRefDatabase().getRefsByPrefix(RefNames.refsDraftCommentsPrefix(virtualId));
+  }
+
   public static <T extends Comment> List<T> sort(List<T> comments) {
     comments.sort(COMMENT_ORDER);
     return comments;
   }
+
+  private Change.Id getVirtualId(ChangeNotes notes) {
+    return virtualIdAlgorithm == null
+        ? notes.getChangeId()
+        : virtualIdAlgorithm.apply(notes.getServerId(), notes.getChangeId());
+  }
 }
diff --git a/java/com/google/gerrit/server/account/AccountResource.java b/java/com/google/gerrit/server/account/AccountResource.java
index 9629809eca..14b363b2f7 100644
--- a/java/com/google/gerrit/server/account/AccountResource.java
+++ b/java/com/google/gerrit/server/account/AccountResource.java
@@ -99,6 +99,10 @@ public class AccountResource implements RestResource {
     public Change getChange() {
       return change.getChange();
     }
+
+    public Change.Id getVirtualId() {
+      return change.getVirtualId();
+    }
   }
 
   public static class Star implements RestResource {
diff --git a/java/com/google/gerrit/server/change/ChangeJson.java b/java/com/google/gerrit/server/change/ChangeJson.java
index beff1a36a6..2fce4755b5 100644
--- a/java/com/google/gerrit/server/change/ChangeJson.java
+++ b/java/com/google/gerrit/server/change/ChangeJson.java
@@ -490,6 +490,9 @@ public class ChangeJson {
       if (has(REVIEWED) && userProvider.get().isIdentifiedUser()) {
         ChangeData.ensureReviewedByLoadedForOpenChanges(all);
       }
+      if (has(STAR) && userProvider.get().isIdentifiedUser()) {
+        ChangeData.ensureChangeServerId(all);
+      }
       ChangeData.ensureCurrentApprovalsLoaded(all);
     } else {
       for (ChangeData cd : all) {
@@ -781,6 +784,8 @@ public class ChangeJson {
               .collect(toList());
     }
 
+    out._virtualIdNumber = cd.virtualId().get();
+
     return out;
   }
 
@@ -972,14 +977,15 @@ public class ChangeJson {
     // repository only once
     try (Repository allUsersRepo = repoManager.openRepository(allUsers)) {
       List<Change.Id> changeIds =
-          changeInfos.stream().map(c -> Change.id(c._number)).collect(Collectors.toList());
+          changeInfos.stream().map(c -> Change.id(c._virtualIdNumber)).collect(Collectors.toList());
       Set<Change.Id> starredChanges =
           starredChangesreader.areStarred(
               allUsersRepo, changeIds, userProvider.get().asIdentifiedUser().getAccountId());
       if (starredChanges.isEmpty()) {
         return;
       }
-      changeInfos.stream().forEach(c -> c.starred = starredChanges.contains(Change.id(c._number)));
+      changeInfos.stream()
+          .forEach(c -> c.starred = starredChanges.contains(Change.id(c._virtualIdNumber)));
     } catch (IOException e) {
       logger.atWarning().withCause(e).log("Failed to open All-Users repo.");
     }
diff --git a/java/com/google/gerrit/server/change/ChangeResource.java b/java/com/google/gerrit/server/change/ChangeResource.java
index 481c17b89c..fe7fd8e07d 100644
--- a/java/com/google/gerrit/server/change/ChangeResource.java
+++ b/java/com/google/gerrit/server/change/ChangeResource.java
@@ -161,6 +161,10 @@ public class ChangeResource implements RestResource, HasETag {
     return changeData;
   }
 
+  public Change.Id getVirtualId() {
+    return getChangeData().virtualId();
+  }
+
   // This includes all information relevant for ETag computation
   // unrelated to the UI.
   public void prepareETag(Hasher h, CurrentUser user) {
@@ -237,7 +241,7 @@ public class ChangeResource implements RestResource, HasETag {
                 .build())) {
       Hasher h = Hashing.murmur3_128().newHasher();
       if (user.isIdentifiedUser()) {
-        h.putBoolean(starredChangesReader.isStarred(user.getAccountId(), getId()));
+        h.putBoolean(starredChangesReader.isStarred(user.getAccountId(), getVirtualId()));
       }
       prepareETag(h, user);
       return h.hash().toString();
diff --git a/java/com/google/gerrit/server/change/DeleteChangeOp.java b/java/com/google/gerrit/server/change/DeleteChangeOp.java
index bc54ce473e..7789392c5b 100644
--- a/java/com/google/gerrit/server/change/DeleteChangeOp.java
+++ b/java/com/google/gerrit/server/change/DeleteChangeOp.java
@@ -80,7 +80,8 @@ public class DeleteChangeOp implements BatchUpdateOp {
     ensureDeletable(ctx, id, patchSets);
     // Cleaning up is only possible as long as the change and its elements are
     // still part of the database.
-    cleanUpReferences(id);
+    ChangeData cd = changeDataFactory.create(ctx.getChange());
+    cleanUpReferences(cd);
 
     logger.atFine().log(
         "Deleting change %s, current patch set %d is commit %s",
@@ -94,7 +95,7 @@ public class DeleteChangeOp implements BatchUpdateOp {
                     .map(p -> p.commitId().name())
                     .orElse("n/a")));
     ctx.deleteChange();
-    changeDeleted.fire(changeDataFactory.create(ctx.getChange()), ctx.getAccount(), ctx.getWhen());
+    changeDeleted.fire(cd, ctx.getAccount(), ctx.getWhen());
     return true;
   }
 
@@ -123,11 +124,11 @@ public class DeleteChangeOp implements BatchUpdateOp {
         revWalk.parseCommit(patchSet.commitId()), revWalk.parseCommit(destId.get()));
   }
 
-  private void cleanUpReferences(Change.Id id) throws IOException {
-    accountPatchReviewStore.run(s -> s.clearReviewed(id));
+  private void cleanUpReferences(ChangeData cd) throws IOException {
+    accountPatchReviewStore.run(s -> s.clearReviewed(cd.getId()));
 
     // Non-atomic operation on All-Users refs; not much we can do to make it atomic.
-    starredChangesWriter.unstarAllForChangeDeletion(id);
+    starredChangesWriter.unstarAllForChangeDeletion(cd.virtualId());
   }
 
   @Override
diff --git a/java/com/google/gerrit/server/index/change/ChangeField.java b/java/com/google/gerrit/server/index/change/ChangeField.java
index f859fe93e9..2b91d9adc8 100644
--- a/java/com/google/gerrit/server/index/change/ChangeField.java
+++ b/java/com/google/gerrit/server/index/change/ChangeField.java
@@ -128,7 +128,7 @@ public class ChangeField {
           .required()
           // The numeric change id is integer in string form
           .size(10)
-          .build(cd -> String.valueOf(cd.getVirtualId().get()));
+          .build(cd -> String.valueOf(cd.virtualId().get()));
 
   public static final IndexedField<ChangeData, String>.SearchSpec NUMERIC_ID_STR_SPEC =
       NUMERIC_ID_STR_FIELD.exact("legacy_id_str");
diff --git a/java/com/google/gerrit/server/notedb/ChangeDraftNotesUpdate.java b/java/com/google/gerrit/server/notedb/ChangeDraftNotesUpdate.java
index 8faca679d4..b15cb503a1 100644
--- a/java/com/google/gerrit/server/notedb/ChangeDraftNotesUpdate.java
+++ b/java/com/google/gerrit/server/notedb/ChangeDraftNotesUpdate.java
@@ -30,6 +30,7 @@ import com.google.gerrit.exceptions.StorageException;
 import com.google.gerrit.server.ChangeDraftUpdate;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.config.AllUsersName;
+import com.google.gerrit.server.query.change.ChangeNumberVirtualIdAlgorithm;
 import com.google.inject.assistedinject.Assisted;
 import com.google.inject.assistedinject.AssistedInject;
 import java.io.IOException;
@@ -57,6 +58,8 @@ import org.eclipse.jgit.revwalk.RevWalk;
  * <p>This class is not thread safe.
  */
 public class ChangeDraftNotesUpdate extends AbstractChangeUpdate implements ChangeDraftUpdate {
+  private final ChangeNumberVirtualIdAlgorithm virtualIdFunc;
+
   public interface Factory extends ChangeDraftUpdateFactory {
     @Override
     ChangeDraftNotesUpdate create(
@@ -103,6 +106,7 @@ public class ChangeDraftNotesUpdate extends AbstractChangeUpdate implements Chan
       @GerritPersonIdent PersonIdent serverIdent,
       AllUsersName allUsers,
       ChangeNoteUtil noteUtil,
+      @Nullable ChangeNumberVirtualIdAlgorithm virtualIdFunc,
       @Assisted ChangeNotes notes,
       @Assisted("effective") Account.Id accountId,
       @Assisted("real") Account.Id realAccountId,
@@ -110,6 +114,7 @@ public class ChangeDraftNotesUpdate extends AbstractChangeUpdate implements Chan
       @Assisted Instant when) {
     super(noteUtil, serverIdent, notes, null, accountId, realAccountId, authorIdent, when);
     this.draftsProject = allUsers;
+    this.virtualIdFunc = virtualIdFunc;
   }
 
   @AssistedInject
@@ -117,6 +122,7 @@ public class ChangeDraftNotesUpdate extends AbstractChangeUpdate implements Chan
       @GerritPersonIdent PersonIdent serverIdent,
       AllUsersName allUsers,
       ChangeNoteUtil noteUtil,
+      @Nullable ChangeNumberVirtualIdAlgorithm virtualIdFunc,
       @Assisted Change change,
       @Assisted("effective") Account.Id accountId,
       @Assisted("real") Account.Id realAccountId,
@@ -124,6 +130,7 @@ public class ChangeDraftNotesUpdate extends AbstractChangeUpdate implements Chan
       @Assisted Instant when) {
     super(noteUtil, serverIdent, null, change, accountId, realAccountId, authorIdent, when);
     this.draftsProject = allUsers;
+    this.virtualIdFunc = virtualIdFunc;
   }
 
   @Override
@@ -177,6 +184,7 @@ public class ChangeDraftNotesUpdate extends AbstractChangeUpdate implements Chan
             authorIdent,
             draftsProject,
             noteUtil,
+            virtualIdFunc,
             new Change(getChange()),
             accountId,
             realAccountId,
@@ -283,7 +291,7 @@ public class ChangeDraftNotesUpdate extends AbstractChangeUpdate implements Chan
 
   @Override
   protected String getRefName() {
-    return RefNames.refsDraftComments(getId(), accountId);
+    return RefNames.refsDraftComments(getVirtualId(), accountId);
   }
 
   @Override
@@ -306,4 +314,11 @@ public class ChangeDraftNotesUpdate extends AbstractChangeUpdate implements Chan
     }
     return Optional.empty();
   }
+
+  private Change.Id getVirtualId() {
+    Change change = getChange();
+    return virtualIdFunc == null
+        ? change.getId()
+        : virtualIdFunc.apply(change.getServerId(), change.getId());
+  }
 }
diff --git a/java/com/google/gerrit/server/notedb/ChangeNotes.java b/java/com/google/gerrit/server/notedb/ChangeNotes.java
index 7f0b0682d7..cee98d154b 100644
--- a/java/com/google/gerrit/server/notedb/ChangeNotes.java
+++ b/java/com/google/gerrit/server/notedb/ChangeNotes.java
@@ -550,11 +550,20 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
   }
 
   public ImmutableList<HumanComment> getDraftComments(Account.Id author) {
-    return getDraftComments(author, null);
+    return getDraftComments(author, null, null);
   }
 
-  ImmutableList<HumanComment> getDraftComments(Account.Id author, @Nullable Ref ref) {
-    loadDraftComments(author, ref);
+  public ImmutableList<HumanComment> getDraftComments(Account.Id author, Ref ref) {
+    return getDraftComments(author, null, ref);
+  }
+
+  public ImmutableList<HumanComment> getDraftComments(Account.Id author, Change.Id virtualId) {
+    return getDraftComments(author, virtualId, null);
+  }
+
+  ImmutableList<HumanComment> getDraftComments(
+      Account.Id author, @Nullable Change.Id virtualId, @Nullable Ref ref) {
+    loadDraftComments(author, virtualId, ref);
     // Filter out any zombie draft comments. These are drafts that are also in
     // the published map, and arise when the update to All-Users to delete them
     // during the publish operation failed.
@@ -573,9 +582,10 @@ public class ChangeNotes extends AbstractChangeNotes<ChangeNotes> {
    * However, this method will load the comments if no draft comments have been loaded or if the
    * caller would like the drafts for another author.
    */
-  private void loadDraftComments(Account.Id author, @Nullable Ref ref) {
+  private void loadDraftComments(
+      Account.Id author, @Nullable Change.Id virtualId, @Nullable Ref ref) {
     if (draftCommentNotes == null || !author.equals(draftCommentNotes.getAuthor()) || ref != null) {
-      draftCommentNotes = new DraftCommentNotes(args, getChangeId(), author, ref);
+      draftCommentNotes = new DraftCommentNotes(args, getChangeId(), virtualId, author, ref);
       draftCommentNotes.load();
     }
   }
diff --git a/java/com/google/gerrit/server/notedb/ChangeNotesState.java b/java/com/google/gerrit/server/notedb/ChangeNotesState.java
index 304b54d456..6b208f3fae 100644
--- a/java/com/google/gerrit/server/notedb/ChangeNotesState.java
+++ b/java/com/google/gerrit/server/notedb/ChangeNotesState.java
@@ -364,6 +364,7 @@ public abstract class ChangeNotesState {
     change.setOwner(c.owner());
     change.setDest(BranchNameKey.create(change.getProject(), c.branch()));
     change.setCreatedOn(c.createdOn());
+    change.setServerId(serverId());
     copyNonConstructorColumnsTo(change);
   }
 
diff --git a/java/com/google/gerrit/server/notedb/DraftCommentNotes.java b/java/com/google/gerrit/server/notedb/DraftCommentNotes.java
index 186b49a8d8..639633e6e0 100644
--- a/java/com/google/gerrit/server/notedb/DraftCommentNotes.java
+++ b/java/com/google/gerrit/server/notedb/DraftCommentNotes.java
@@ -42,8 +42,15 @@ import org.eclipse.jgit.revwalk.RevCommit;
 public class DraftCommentNotes extends AbstractChangeNotes<DraftCommentNotes> {
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
+  private final Change.Id virtualId;
+
   public interface Factory {
     DraftCommentNotes create(Change.Id changeId, Account.Id accountId);
+
+    DraftCommentNotes create(
+        @Assisted("changeId") Change.Id changeId,
+        @Assisted("virtualId") Change.Id virtualId,
+        Account.Id accountId);
   }
 
   private final Account.Id author;
@@ -54,11 +61,26 @@ public class DraftCommentNotes extends AbstractChangeNotes<DraftCommentNotes> {
 
   @AssistedInject
   DraftCommentNotes(Args args, @Assisted Change.Id changeId, @Assisted Account.Id author) {
-    this(args, changeId, author, null);
+    this(args, changeId, null, author, null);
+  }
+
+  @AssistedInject
+  DraftCommentNotes(
+      Args args,
+      @Assisted("changeId") Change.Id changeId,
+      @Assisted("virtualId") Change.Id virtualId,
+      @Assisted Account.Id author) {
+    this(args, changeId, virtualId, author, null);
   }
 
-  DraftCommentNotes(Args args, Change.Id changeId, Account.Id author, @Nullable Ref ref) {
+  DraftCommentNotes(
+      Args args,
+      Change.Id changeId,
+      @Nullable Change.Id virtualId,
+      Account.Id author,
+      @Nullable Ref ref) {
     super(args, changeId, null);
+    this.virtualId = virtualId;
     this.author = requireNonNull(author);
     this.ref = ref;
     if (ref != null) {
@@ -94,7 +116,7 @@ public class DraftCommentNotes extends AbstractChangeNotes<DraftCommentNotes> {
 
   @Override
   protected String getRefName() {
-    return refsDraftComments(getChangeId(), author);
+    return refsDraftComments(virtualId != null ? virtualId : getChangeId(), author);
   }
 
   @Override
diff --git a/java/com/google/gerrit/server/notedb/StarredChangesUtilNoteDbImpl.java b/java/com/google/gerrit/server/notedb/StarredChangesUtilNoteDbImpl.java
index 7dc8f59f83..d5258b1b4e 100644
--- a/java/com/google/gerrit/server/notedb/StarredChangesUtilNoteDbImpl.java
+++ b/java/com/google/gerrit/server/notedb/StarredChangesUtilNoteDbImpl.java
@@ -84,31 +84,31 @@ public class StarredChangesUtilNoteDbImpl implements StarredChangesUtil {
   }
 
   @Override
-  public boolean isStarred(Account.Id accountId, Change.Id changeId) {
+  public boolean isStarred(Account.Id accountId, Change.Id virtualId) {
     try (Repository repo = repoManager.openRepository(allUsers)) {
-      return getStarRef(repo, RefNames.refsStarredChanges(changeId, accountId)).isPresent();
+      return getStarRef(repo, RefNames.refsStarredChanges(virtualId, accountId)).isPresent();
     } catch (IOException e) {
       throw new StorageException(
           String.format(
               "Reading stars from change %d for account %d failed",
-              changeId.get(), accountId.get()),
+              virtualId.get(), accountId.get()),
           e);
     }
   }
 
   @Override
-  public void star(Account.Id accountId, Change.Id changeId) {
-    updateStar(accountId, changeId, true);
+  public void star(Account.Id accountId, Change.Id virtualId) {
+    updateStar(accountId, virtualId, true);
   }
 
   @Override
-  public void unstar(Account.Id accountId, Change.Id changeId) {
-    updateStar(accountId, changeId, false);
+  public void unstar(Account.Id accountId, Change.Id virtualId) {
+    updateStar(accountId, virtualId, false);
   }
 
-  private void updateStar(Account.Id accountId, Change.Id changeId, boolean shouldAdd) {
+  private void updateStar(Account.Id accountId, Change.Id virtualId, boolean shouldAdd) {
     try (Repository repo = repoManager.openRepository(allUsers)) {
-      String refName = RefNames.refsStarredChanges(changeId, accountId);
+      String refName = RefNames.refsStarredChanges(virtualId, accountId);
       if (shouldAdd) {
         addRef(repo, refName, null);
       } else {
@@ -119,16 +119,16 @@ public class StarredChangesUtilNoteDbImpl implements StarredChangesUtil {
       }
     } catch (IOException e) {
       throw new StorageException(
-          String.format("Star change %d for account %d failed", changeId.get(), accountId.get()),
+          String.format("Star change %d for account %d failed", virtualId.get(), accountId.get()),
           e);
     }
   }
 
   @Override
   public Set<Change.Id> areStarred(
-      Repository allUsersRepo, List<Change.Id> changeIds, Account.Id caller) {
+      Repository allUsersRepo, List<Change.Id> virtualIds, Account.Id caller) {
     List<String> starRefs =
-        changeIds.stream()
+        virtualIds.stream()
             .map(c -> RefNames.refsStarredChanges(c, caller))
             .collect(Collectors.toList());
     try {
@@ -139,21 +139,21 @@ public class StarredChangesUtilNoteDbImpl implements StarredChangesUtil {
     } catch (IOException e) {
       logger.atWarning().withCause(e).log(
           "Failed getting starred changes for account %d within changes: %s",
-          caller.get(), Joiner.on(", ").join(changeIds));
+          caller.get(), Joiner.on(", ").join(virtualIds));
       return ImmutableSet.of();
     }
   }
 
   @Override
-  public void unstarAllForChangeDeletion(Change.Id changeId) throws IOException {
+  public void unstarAllForChangeDeletion(Change.Id virtualId) throws IOException {
     try (Repository repo = repoManager.openRepository(allUsers);
         RevWalk rw = new RevWalk(repo)) {
       BatchRefUpdate batchUpdate = repo.getRefDatabase().newBatchUpdate();
       batchUpdate.setAllowNonFastForwards(true);
       batchUpdate.setRefLogIdent(serverIdent.get());
-      batchUpdate.setRefLogMessage("Unstar change " + changeId.get(), true);
-      for (Account.Id accountId : getStars(repo, changeId)) {
-        String refName = RefNames.refsStarredChanges(changeId, accountId);
+      batchUpdate.setRefLogMessage("Unstar change " + virtualId.get(), true);
+      for (Account.Id accountId : getStars(repo, virtualId)) {
+        String refName = RefNames.refsStarredChanges(virtualId, accountId);
         Ref ref = repo.getRefDatabase().exactRef(refName);
         if (ref != null) {
           batchUpdate.addCommand(new ReceiveCommand(ref.getObjectId(), ObjectId.zeroId(), refName));
@@ -165,7 +165,7 @@ public class StarredChangesUtilNoteDbImpl implements StarredChangesUtil {
           String message =
               String.format(
                   "Unstar change %d failed, ref %s could not be deleted: %s",
-                  changeId.get(), command.getRefName(), command.getResult());
+                  virtualId.get(), command.getRefName(), command.getResult());
           if (command.getResult() == ReceiveCommand.Result.LOCK_FAILURE) {
             throw new LockFailureException(message, batchUpdate);
           }
@@ -176,11 +176,11 @@ public class StarredChangesUtilNoteDbImpl implements StarredChangesUtil {
   }
 
   @Override
-  public ImmutableMap<Account.Id, Ref> byChange(Change.Id changeId) {
+  public ImmutableMap<Account.Id, Ref> byChange(Change.Id virtualId) {
     try (Repository repo = repoManager.openRepository(allUsers)) {
       ImmutableMap.Builder<Account.Id, Ref> builder = ImmutableMap.builder();
-      for (Account.Id accountId : getStars(repo, changeId)) {
-        Optional<Ref> starRef = getStarRef(repo, RefNames.refsStarredChanges(changeId, accountId));
+      for (Account.Id accountId : getStars(repo, virtualId)) {
+        Optional<Ref> starRef = getStarRef(repo, RefNames.refsStarredChanges(virtualId, accountId));
         if (starRef.isPresent()) {
           builder.put(accountId, starRef.get());
         }
@@ -188,7 +188,7 @@ public class StarredChangesUtilNoteDbImpl implements StarredChangesUtil {
       return builder.build();
     } catch (IOException e) {
       throw new StorageException(
-          String.format("Get accounts that starred change %d failed", changeId.get()), e);
+          String.format("Get accounts that starred change %d failed", virtualId.get()), e);
     }
   }
 
@@ -222,9 +222,9 @@ public class StarredChangesUtilNoteDbImpl implements StarredChangesUtil {
     }
   }
 
-  private static Set<Account.Id> getStars(Repository allUsers, Change.Id changeId)
+  private static Set<Account.Id> getStars(Repository allUsers, Change.Id virtualId)
       throws IOException {
-    String prefix = RefNames.refsStarredChangesPrefix(changeId);
+    String prefix = RefNames.refsStarredChangesPrefix(virtualId);
     RefDatabase refDb = allUsers.getRefDatabase();
     return refDb.getRefsByPrefix(prefix).stream()
         .map(r -> r.getName().substring(prefix.length()))
diff --git a/java/com/google/gerrit/server/query/change/ChangeData.java b/java/com/google/gerrit/server/query/change/ChangeData.java
index 9522b832df..4718a69041 100644
--- a/java/com/google/gerrit/server/query/change/ChangeData.java
+++ b/java/com/google/gerrit/server/query/change/ChangeData.java
@@ -77,7 +77,6 @@ import com.google.gerrit.server.change.MergeabilityCache;
 import com.google.gerrit.server.change.PureRevert;
 import com.google.gerrit.server.config.AllUsersName;
 import com.google.gerrit.server.config.GerritServerConfig;
-import com.google.gerrit.server.config.GerritServerId;
 import com.google.gerrit.server.config.SkipCurrentRulesEvaluationOnClosedChanges;
 import com.google.gerrit.server.config.TrackingFooters;
 import com.google.gerrit.server.git.GitRepositoryManager;
@@ -109,6 +108,7 @@ import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.Function;
@@ -241,11 +241,11 @@ public class ChangeData {
     }
 
     public ChangeData create(Project.NameKey project, Change.Id id) {
-      return assistedFactory.create(project, id, null, null);
+      return assistedFactory.create(project, id, null, null, null);
     }
 
     public ChangeData create(Project.NameKey project, Change.Id id, ObjectId metaRevision) {
-      ChangeData cd = assistedFactory.create(project, id, null, null);
+      ChangeData cd = assistedFactory.create(project, id, null, null, null);
       cd.setMetaRevision(metaRevision);
       return cd;
     }
@@ -258,19 +258,29 @@ public class ChangeData {
     }
 
     public ChangeData create(Change change) {
-      return assistedFactory.create(change.getProject(), change.getId(), change, null);
+      return create(change, null);
+    }
+
+    public ChangeData create(Change change, Change.Id virtualId) {
+      return assistedFactory.create(
+          change.getProject(),
+          change.getId(),
+          !Objects.equals(virtualId, change.getId()) ? virtualId : null,
+          change,
+          null);
     }
 
     public ChangeData create(ChangeNotes notes) {
       return assistedFactory.create(
-          notes.getChange().getProject(), notes.getChangeId(), notes.getChange(), notes);
+          notes.getChange().getProject(), notes.getChangeId(), null, notes.getChange(), notes);
     }
   }
 
   public interface AssistedFactory {
     ChangeData create(
         Project.NameKey project,
-        Change.Id id,
+        @Assisted("changeId") Change.Id id,
+        @Assisted("virtualId") @Nullable Change.Id virtualId,
         @Nullable Change change,
         @Nullable ChangeNotes notes);
   }
@@ -289,7 +299,7 @@ public class ChangeData {
    */
   public static ChangeData createForTest(
       Project.NameKey project, Change.Id id, int currentPatchSetId, ObjectId commitId) {
-    return createForTest(project, id, currentPatchSetId, commitId, null, null, null);
+    return createForTest(project, id, currentPatchSetId, commitId, null, null);
   }
 
   /**
@@ -302,7 +312,6 @@ public class ChangeData {
    * @param id change ID
    * @param currentPatchSetId current patchset number
    * @param commitId commit SHA1 of the current patchset
-   * @param serverId Gerrit server id
    * @param virtualIdAlgo algorithm for virtualising the Change number
    * @param changeNotes notes associated with the Change
    * @return instance for testing.
@@ -312,7 +321,6 @@ public class ChangeData {
       Change.Id id,
       int currentPatchSetId,
       ObjectId commitId,
-      @Nullable String serverId,
       @Nullable ChangeNumberVirtualIdAlgorithm virtualIdAlgo,
       @Nullable ChangeNotes changeNotes) {
     ChangeData cd =
@@ -336,12 +344,12 @@ public class ChangeData {
             null,
             null,
             null,
-            serverId,
             virtualIdAlgo,
             false,
             project,
             id,
             null,
+            null,
             changeNotes);
     cd.currentPatchSet =
         PatchSet.builder()
@@ -445,10 +453,10 @@ public class ChangeData {
   private Optional<Instant> mergedOn;
   private ImmutableSetMultimap<NameKey, RefState> refStates;
   private ImmutableList<byte[]> refStatePatterns;
-  private String gerritServerId;
   private String changeServerId;
   private ChangeNumberVirtualIdAlgorithm virtualIdFunc;
   private Boolean failedParsingFromIndex = false;
+  private Change.Id virtualId;
 
   @Inject
   private ChangeData(
@@ -471,11 +479,11 @@ public class ChangeData {
       SubmitRequirementsEvaluator submitRequirementsEvaluator,
       SubmitRequirementsUtil submitRequirementsUtil,
       SubmitRuleEvaluator.Factory submitRuleEvaluatorFactory,
-      @GerritServerId String gerritServerId,
       ChangeNumberVirtualIdAlgorithm virtualIdFunc,
       @SkipCurrentRulesEvaluationOnClosedChanges Boolean skipCurrentRulesEvaluationOnClosedChange,
       @Assisted Project.NameKey project,
-      @Assisted Change.Id id,
+      @Assisted("changeId") Change.Id id,
+      @Assisted("virtualId") @Nullable Change.Id virtualId,
       @Assisted @Nullable Change change,
       @Assisted @Nullable ChangeNotes notes) {
     this.approvalsUtil = approvalsUtil;
@@ -509,8 +517,8 @@ public class ChangeData {
     this.notes = notes;
 
     this.changeServerId = notes == null ? null : notes.getServerId();
-    this.gerritServerId = gerritServerId;
     this.virtualIdFunc = virtualIdFunc;
+    this.virtualId = virtualId;
   }
 
   /**
@@ -640,12 +648,33 @@ public class ChangeData {
     return legacyId;
   }
 
-  public Change.Id getVirtualId() {
-    if (virtualIdFunc == null || changeServerId == null || changeServerId.equals(gerritServerId)) {
-      return legacyId;
+  public static void ensureChangeServerId(Iterable<ChangeData> changes) {
+    ChangeData first = Iterables.getFirst(changes, null);
+    if (first == null) {
+      return;
     }
 
-    return Change.id(virtualIdFunc.apply(changeServerId, legacyId.get()));
+    for (ChangeData cd : changes) {
+      cd.changeServerId();
+    }
+  }
+
+  @Nullable
+  public String changeServerId() {
+    if (changeServerId == null) {
+      if (!lazyload()) {
+        return null;
+      }
+      changeServerId = notes().getServerId();
+    }
+    return changeServerId;
+  }
+
+  public Change.Id virtualId() {
+    if (virtualId == null) {
+      return virtualIdFunc == null ? legacyId : virtualIdFunc.apply(changeServerId, legacyId);
+    }
+    return virtualId;
   }
 
   public Project.NameKey project() {
@@ -1417,7 +1446,7 @@ public class ChangeData {
       if (!lazyload()) {
         return ImmutableMap.of();
       }
-      starRefs = requireNonNull(starredChangesReader).byChange(legacyId);
+      starRefs = requireNonNull(starredChangesReader).byChange(virtualId());
     }
     return starRefs;
   }
diff --git a/java/com/google/gerrit/server/query/change/ChangeNumberBitmapMaskAlgorithm.java b/java/com/google/gerrit/server/query/change/ChangeNumberBitmapMaskAlgorithm.java
index 726a3767c4..95c287a21e 100644
--- a/java/com/google/gerrit/server/query/change/ChangeNumberBitmapMaskAlgorithm.java
+++ b/java/com/google/gerrit/server/query/change/ChangeNumberBitmapMaskAlgorithm.java
@@ -16,7 +16,9 @@ package com.google.gerrit.server.query.change;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.gerrit.entities.Change;
 import com.google.gerrit.server.config.GerritImportedServerIds;
+import com.google.gerrit.server.config.GerritServerId;
 import com.google.inject.Inject;
 import com.google.inject.ProvisionException;
 import com.google.inject.Singleton;
@@ -38,9 +40,11 @@ public class ChangeNumberBitmapMaskAlgorithm implements ChangeNumberVirtualIdAlg
       Integer.BYTES * 8 - CHANGE_NUM_BIT_LEN; // Allows up to 64 ServerIds
 
   private final ImmutableMap<String, Integer> serverIdCodes;
+  private final String localServerId;
 
   @Inject
   public ChangeNumberBitmapMaskAlgorithm(
+      @GerritServerId String localServerId,
       @GerritImportedServerIds ImmutableList<String> importedServerIds) {
     if (importedServerIds.size() >= 1 << SERVER_ID_BIT_LEN) {
       throw new ProvisionException(
@@ -54,10 +58,17 @@ public class ChangeNumberBitmapMaskAlgorithm implements ChangeNumberVirtualIdAlg
     }
 
     serverIdCodes = serverIdCodesBuilder.build();
+    this.localServerId = localServerId;
   }
 
   @Override
-  public int apply(String changeServerId, int changeNum) {
+  public Change.Id apply(String changeServerId, Change.Id changeNumId) {
+    if (changeServerId == null || localServerId.equals(changeServerId)) {
+      return changeNumId;
+    }
+
+    int changeNum = changeNumId.get();
+
     if ((changeNum & LEGACY_ID_BIT_MASK) != changeNum) {
       throw new IllegalArgumentException(
           String.format(
@@ -71,6 +82,6 @@ public class ChangeNumberBitmapMaskAlgorithm implements ChangeNumberVirtualIdAlg
     }
     int virtualId = (changeNum & LEGACY_ID_BIT_MASK) | (encodedServerId << CHANGE_NUM_BIT_LEN);
 
-    return virtualId;
+    return Change.id(virtualId);
   }
 }
diff --git a/java/com/google/gerrit/server/query/change/ChangeNumberVirtualIdAlgorithm.java b/java/com/google/gerrit/server/query/change/ChangeNumberVirtualIdAlgorithm.java
index ab217050b9..6daf16f266 100644
--- a/java/com/google/gerrit/server/query/change/ChangeNumberVirtualIdAlgorithm.java
+++ b/java/com/google/gerrit/server/query/change/ChangeNumberVirtualIdAlgorithm.java
@@ -14,6 +14,7 @@
 
 package com.google.gerrit.server.query.change;
 
+import com.google.gerrit.entities.Change;
 import com.google.inject.ImplementedBy;
 
 /**
@@ -31,5 +32,5 @@ public interface ChangeNumberVirtualIdAlgorithm {
    * @param legacyChangeNum legacy change number
    * @return virtual id which combines serverId and legacyChangeNum together
    */
-  int apply(String serverId, int legacyChangeNum);
+  Change.Id apply(String serverId, Change.Id legacyChangeNum);
 }
diff --git a/java/com/google/gerrit/server/restapi/account/StarredChanges.java b/java/com/google/gerrit/server/restapi/account/StarredChanges.java
index 1565aba05f..95aa07c7d7 100644
--- a/java/com/google/gerrit/server/restapi/account/StarredChanges.java
+++ b/java/com/google/gerrit/server/restapi/account/StarredChanges.java
@@ -69,7 +69,7 @@ public class StarredChanges
       throws RestApiException, PermissionBackendException, IOException {
     IdentifiedUser user = parent.getUser();
     ChangeResource change = changes.parse(TopLevelResource.INSTANCE, id);
-    if (starredChangesReader.isStarred(user.getAccountId(), change.getId())) {
+    if (starredChangesReader.isStarred(user.getAccountId(), change.getVirtualId())) {
       return new AccountResource.StarredChange(user, change);
     }
     throw new ResourceNotFoundException(id);
@@ -125,7 +125,7 @@ public class StarredChanges
       }
 
       try {
-        starredChangesWriter.star(self.get().getAccountId(), change.getId());
+        starredChangesWriter.star(self.get().getAccountId(), change.getVirtualId());
       } catch (DuplicateKeyException e) {
         return Response.none();
       }
@@ -168,7 +168,7 @@ public class StarredChanges
       if (!self.get().hasSameAccountId(rsrc.getUser())) {
         throw new AuthException("not allowed remove starred change");
       }
-      starredChangesWriter.unstar(self.get().getAccountId(), rsrc.getChange().getId());
+      starredChangesWriter.unstar(self.get().getAccountId(), rsrc.getVirtualId());
       return Response.none();
     }
   }
diff --git a/javatests/com/google/gerrit/entities/converter/ChangeProtoConverterTest.java b/javatests/com/google/gerrit/entities/converter/ChangeProtoConverterTest.java
index bbf10bd6f5..812a0dfa37 100644
--- a/javatests/com/google/gerrit/entities/converter/ChangeProtoConverterTest.java
+++ b/javatests/com/google/gerrit/entities/converter/ChangeProtoConverterTest.java
@@ -32,6 +32,7 @@ import org.junit.Test;
 
 public class ChangeProtoConverterTest {
   private final ChangeProtoConverter changeProtoConverter = ChangeProtoConverter.INSTANCE;
+  private static final String TEST_SERVER_ID = "test-server-id";
 
   @Test
   public void allValuesConvertedToProto() {
@@ -42,6 +43,7 @@ public class ChangeProtoConverterTest {
             Account.id(35),
             BranchNameKey.create(Project.nameKey("project 67"), "branch 74"),
             Instant.ofEpochMilli(987654L));
+    change.setServerId(TEST_SERVER_ID);
     change.setLastUpdatedOn(Instant.ofEpochMilli(1234567L));
     change.setStatus(Change.Status.MERGED);
     change.setCurrentPatchSet(
@@ -89,6 +91,7 @@ public class ChangeProtoConverterTest {
             Account.id(35),
             BranchNameKey.create(Project.nameKey("project 67"), "branch-74"),
             Instant.ofEpochMilli(987654L));
+    change.setServerId(TEST_SERVER_ID);
 
     Entities.Change proto = changeProtoConverter.toProto(change);
 
@@ -124,6 +127,7 @@ public class ChangeProtoConverterTest {
             Account.id(35),
             BranchNameKey.create(Project.nameKey("project 67"), "branch-74"),
             Instant.ofEpochMilli(987654L));
+    change.setServerId(TEST_SERVER_ID);
     // O as ID actually means that no current patch set is present.
     change.setCurrentPatchSet(PatchSet.id(Change.id(14), 0), null, null);
 
@@ -161,6 +165,7 @@ public class ChangeProtoConverterTest {
             Account.id(35),
             BranchNameKey.create(Project.nameKey("project 67"), "branch-74"),
             Instant.ofEpochMilli(987654L));
+    change.setServerId(TEST_SERVER_ID);
     change.setCurrentPatchSet(PatchSet.id(Change.id(14), 23), "subject ABC", null);
 
     Entities.Change proto = changeProtoConverter.toProto(change);
@@ -189,7 +194,7 @@ public class ChangeProtoConverterTest {
   }
 
   @Test
-  public void allValuesConvertedToProtoAndBackAgain() {
+  public void allValuesConvertedToProtoAndBackAgainExceptServerId() {
     Change change =
         new Change(
             Change.key("change 1"),
@@ -197,6 +202,7 @@ public class ChangeProtoConverterTest {
             Account.id(35),
             BranchNameKey.create(Project.nameKey("project 67"), "branch-74"),
             Instant.ofEpochMilli(987654L));
+    change.setServerId(TEST_SERVER_ID);
     change.setLastUpdatedOn(Instant.ofEpochMilli(1234567L));
     change.setStatus(Change.Status.MERGED);
     change.setCurrentPatchSet(
@@ -209,6 +215,11 @@ public class ChangeProtoConverterTest {
     change.setRevertOf(Change.id(180));
 
     Change convertedChange = changeProtoConverter.fromProto(changeProtoConverter.toProto(change));
+
+    // Change serverId is not one of the protobuf definitions, hence is not supposed to be converted
+    // from proto
+    assertThat(convertedChange.getServerId()).isNull();
+    change.setServerId(null);
     assertEqualChange(convertedChange, change);
   }
 
@@ -275,6 +286,7 @@ public class ChangeProtoConverterTest {
         .hasFields(
             ImmutableMap.<String, Type>builder()
                 .put("changeId", Change.Id.class)
+                .put("serverId", String.class)
                 .put("changeKey", Change.Key.class)
                 .put("createdOn", Instant.class)
                 .put("lastUpdatedOn", Instant.class)
@@ -298,6 +310,7 @@ public class ChangeProtoConverterTest {
   // an AutoValue.
   private static void assertEqualChange(Change change, Change expectedChange) {
     assertThat(change.getChangeId()).isEqualTo(expectedChange.getChangeId());
+    assertThat(change.getServerId()).isEqualTo(expectedChange.getServerId());
     assertThat(change.getKey()).isEqualTo(expectedChange.getKey());
     assertThat(change.getCreatedOn()).isEqualTo(expectedChange.getCreatedOn());
     assertThat(change.getLastUpdatedOn()).isEqualTo(expectedChange.getLastUpdatedOn());
diff --git a/javatests/com/google/gerrit/server/index/change/ChangeFieldTest.java b/javatests/com/google/gerrit/server/index/change/ChangeFieldTest.java
index 59b354c0b0..4ce4262475 100644
--- a/javatests/com/google/gerrit/server/index/change/ChangeFieldTest.java
+++ b/javatests/com/google/gerrit/server/index/change/ChangeFieldTest.java
@@ -158,7 +158,7 @@ public class ChangeFieldTest {
   public void tolerateNullValuesForInsertion() {
     Project.NameKey project = Project.nameKey("project");
     ChangeData cd =
-        ChangeData.createForTest(project, Change.id(1), 1, ObjectId.zeroId(), null, null, null);
+        ChangeData.createForTest(project, Change.id(1), 1, ObjectId.zeroId(), null, null);
     assertThat(ChangeField.ADDED_LINES_SPEC.setIfPossible(cd, new FakeStoredValue(null))).isTrue();
   }
 
@@ -166,7 +166,7 @@ public class ChangeFieldTest {
   public void tolerateNullValuesForDeletion() {
     Project.NameKey project = Project.nameKey("project");
     ChangeData cd =
-        ChangeData.createForTest(project, Change.id(1), 1, ObjectId.zeroId(), null, null, null);
+        ChangeData.createForTest(project, Change.id(1), 1, ObjectId.zeroId(), null, null);
     assertThat(ChangeField.DELETED_LINES_SPEC.setIfPossible(cd, new FakeStoredValue(null)))
         .isTrue();
   }
diff --git a/javatests/com/google/gerrit/server/query/change/ChangeDataTest.java b/javatests/com/google/gerrit/server/query/change/ChangeDataTest.java
index 0ce00ebfc7..f954a573eb 100644
--- a/javatests/com/google/gerrit/server/query/change/ChangeDataTest.java
+++ b/javatests/com/google/gerrit/server/query/change/ChangeDataTest.java
@@ -34,8 +34,6 @@ import org.mockito.junit.MockitoJUnitRunner;
 
 @RunWith(MockitoJUnitRunner.class)
 public class ChangeDataTest {
-  private static final String GERRIT_SERVER_ID = UUID.randomUUID().toString();
-
   @Mock private ChangeNotes changeNotesMock;
 
   @Test
@@ -55,7 +53,7 @@ public class ChangeDataTest {
   @Test
   public void getChangeVirtualIdUsingAlgorithm() throws Exception {
     Project.NameKey project = Project.nameKey("project");
-    final int encodedChangeNum = 12345678;
+    final Change.Id encodedChangeNum = Change.id(12345678);
 
     when(changeNotesMock.getServerId()).thenReturn(UUID.randomUUID().toString());
 
@@ -65,11 +63,10 @@ public class ChangeDataTest {
             Change.id(1),
             1,
             ObjectId.zeroId(),
-            GERRIT_SERVER_ID,
             (s, c) -> encodedChangeNum,
             changeNotesMock);
 
-    assertThat(cd.getVirtualId().get()).isEqualTo(encodedChangeNum);
+    assertThat(cd.virtualId().get()).isEqualTo(encodedChangeNum.get());
   }
 
   private static PatchSet newPatchSet(Change.Id changeId, int num) {