Add draft comments to PatchLineCommentsUtil

I added the ability to read and write published comments from either
the notedb or the ReviewDb depending on the state of the
NotesMigration instance. Additionally, I modified all callers of
PatchLineCommentAccess that query for or edit comments to use the
corresponding methods in PatchLineCommentsUtil.

I added a new test to CommentsTest to test the reading and
writing of draft comments from both the notedb and the ReviewDb with
these new PatchLineCommentsUtil methods.

Finally, I added a full integration test for inline comments in
CommentsIT.java.

Change-Id: Iac4ea144497fe68d28c3e886b91c7698741d6615

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/server/change/CommentsIT.java

@@ -0,0 +1,198 @@
+// Copyright (C) 2014 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.acceptance.server.change;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
+import com.google.gerrit.acceptance.AbstractDaemonTest;
+import com.google.gerrit.acceptance.PushOneCommit;
+import com.google.gerrit.acceptance.RestResponse;
+import com.google.gerrit.extensions.api.changes.ReviewInput;
+import com.google.gerrit.extensions.common.Comment;
+import com.google.gerrit.extensions.common.CommentInfo;
+import com.google.gerrit.extensions.restapi.RestApiException;
+import com.google.gerrit.testutil.ConfigSuite;
+import com.google.gson.reflect.TypeToken;
+
+import org.apache.http.HttpStatus;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.lib.Config;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class CommentsIT extends AbstractDaemonTest {
+  @ConfigSuite.Config
+  public static Config noteDbEnabled() {
+    Config cfg = new Config();
+    cfg.setBoolean("notedb", null, "write", true);
+    cfg.setBoolean("notedb", "comments", "read", true);
+    return cfg;
+  }
+
+  @Test
+  public void createDraft() throws GitAPIException, IOException {
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+    String revId = r.getCommit().getName();
+    ReviewInput.CommentInput comment = newCommentInfo(
+        "file1", Comment.Side.REVISION, 1, "comment 1");
+    addDraft(changeId, revId, comment);
+    Map<String, List<CommentInfo>> result = getDraftComments(changeId, revId);
+    assertEquals(1, result.size());
+    CommentInfo actual = Iterables.getOnlyElement(result.get(comment.path));
+    assertCommentInfo(comment, actual);
+  }
+
+  @Test
+  public void postComment() throws RestApiException, Exception {
+    String file = "file";
+    String contents = "contents";
+    PushOneCommit push = pushFactory.create(db, admin.getIdent(),
+        "first subject", file, contents);
+    PushOneCommit.Result r = push.to(git, "refs/for/master");
+    String changeId = r.getChangeId();
+    String revId = r.getCommit().getName();
+    ReviewInput input = new ReviewInput();
+    ReviewInput.CommentInput comment = newCommentInfo(
+        file, Comment.Side.REVISION, 1, "comment 1");
+    input.comments = new HashMap<String, List<ReviewInput.CommentInput>>();
+    input.comments.put(comment.path, Lists.newArrayList(comment));
+    revision(r).review(input);
+    Map<String, List<CommentInfo>> result = getPublishedComments(changeId, revId);
+    assertTrue(!result.isEmpty());
+    CommentInfo actual = Iterables.getOnlyElement(result.get(comment.path));
+    assertCommentInfo(comment, actual);
+  }
+
+  @Test
+  public void putDraft() throws GitAPIException, IOException {
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+    String revId = r.getCommit().getName();
+    ReviewInput.CommentInput comment = newCommentInfo(
+        "file1", Comment.Side.REVISION, 1, "comment 1");
+    addDraft(changeId, revId, comment);
+    Map<String, List<CommentInfo>> result = getDraftComments(changeId, revId);
+    CommentInfo actual = Iterables.getOnlyElement(result.get(comment.path));
+    assertCommentInfo(comment, actual);
+    String uuid = actual.id;
+    comment.message = "updated comment 1";
+    updateDraft(changeId, revId, comment, uuid);
+    result = getDraftComments(changeId, revId);
+    actual = Iterables.getOnlyElement(result.get(comment.path));
+    assertCommentInfo(comment, actual);
+  }
+
+  @Test
+  public void getDraft() throws GitAPIException, IOException {
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+    String revId = r.getCommit().getName();
+    ReviewInput.CommentInput comment = newCommentInfo(
+        "file1", Comment.Side.REVISION, 1, "comment 1");
+    CommentInfo returned = addDraft(changeId, revId, comment);
+    CommentInfo actual = getDraftComment(changeId, revId, returned.id);
+    assertCommentInfo(comment, actual);
+  }
+
+  @Test
+  public void deleteDraft() throws IOException, GitAPIException {
+    PushOneCommit.Result r = createChange();
+    String changeId = r.getChangeId();
+    String revId = r.getCommit().getName();
+    ReviewInput.CommentInput comment = newCommentInfo(
+        "file1", Comment.Side.REVISION, 1, "comment 1");
+    CommentInfo returned = addDraft(changeId, revId, comment);
+    deleteDraft(changeId, revId, returned.id);
+    Map<String, List<CommentInfo>> drafts = getDraftComments(changeId, revId);
+    assertTrue(drafts.isEmpty());
+  }
+
+  private CommentInfo addDraft(String changeId, String revId,
+      ReviewInput.CommentInput c) throws IOException {
+    RestResponse r = userSession.put(
+        "/changes/" + changeId + "/revisions/" + revId + "/drafts", c);
+    assertEquals(HttpStatus.SC_CREATED, r.getStatusCode());
+    return newGson().fromJson(r.getReader(), CommentInfo.class);
+  }
+
+  private void updateDraft(String changeId, String revId,
+      ReviewInput.CommentInput c, String uuid) throws IOException {
+    RestResponse r = userSession.put(
+        "/changes/" + changeId + "/revisions/" + revId + "/drafts/" + uuid, c);
+    assertEquals(HttpStatus.SC_OK, r.getStatusCode());
+  }
+
+  private void deleteDraft(String changeId, String revId, String uuid)
+      throws IOException {
+    RestResponse r = userSession.delete(
+        "/changes/" + changeId + "/revisions/" + revId + "/drafts/" + uuid);
+    assertEquals(HttpStatus.SC_NO_CONTENT, r.getStatusCode());
+  }
+
+  private Map<String, List<CommentInfo>> getPublishedComments(String changeId,
+      String revId) throws IOException {
+    RestResponse r = userSession.get(
+        "/changes/" + changeId + "/revisions/" + revId + "/comments/");
+    assertEquals(HttpStatus.SC_OK, r.getStatusCode());
+    Type mapType = new TypeToken<Map<String, List<CommentInfo>>>() {}.getType();
+    return newGson().fromJson(r.getReader(), mapType);
+  }
+
+  private Map<String, List<CommentInfo>> getDraftComments(String changeId,
+      String revId) throws IOException {
+    RestResponse r = userSession.get(
+        "/changes/" + changeId + "/revisions/" + revId + "/drafts/");
+    assertEquals(HttpStatus.SC_OK, r.getStatusCode());
+    Type mapType = new TypeToken<Map<String, List<CommentInfo>>>() {}.getType();
+    return newGson().fromJson(r.getReader(), mapType);
+  }
+
+  private CommentInfo getDraftComment(String changeId, String revId,
+      String uuid) throws IOException {
+    RestResponse r = userSession.get(
+        "/changes/" + changeId + "/revisions/" + revId + "/drafts/" + uuid);
+    assertEquals(HttpStatus.SC_OK, r.getStatusCode());
+    return newGson().fromJson(r.getReader(), CommentInfo.class);
+  }
+
+  private static void assertCommentInfo(ReviewInput.CommentInput expected,
+      CommentInfo actual) {
+    assertEquals(expected.line, actual.line);
+    assertEquals(expected.message, actual.message);
+    assertEquals(expected.inReplyTo, actual.inReplyTo);
+    if (actual.side == null) {
+      assertEquals(expected.side, Comment.Side.REVISION);
+    }
+  }
+
+  private ReviewInput.CommentInput newCommentInfo(String path,
+      Comment.Side side, int line, String message) {
+    ReviewInput.CommentInput input = new ReviewInput.CommentInput();
+    input.path = path;
+    input.side = side;
+    input.line = line;
+    input.message = message;
+    return input;
+  }
+}

gerrit-httpd/src/main/java/com/google/gerrit/httpd/rpc/changedetail/PatchSetDetailFactory.java

@@ -170,7 +170,8 @@ class PatchSetDetailFactory extends Handler<PatchSetDetail> {
       // quickly locate where they have pending drafts, and review them.
       //
       final Account.Id me = ((IdentifiedUser) user).getAccountId();
-      for (final PatchLineComment c : db.patchComments().draftByPatchSetAuthor(psIdNew, me)) {
+      for (PatchLineComment c
+          : plcUtil.draftByPatchSetAuthor(db, psIdNew, me, notes)) {
         final Patch p = byKey.get(c.getKey().getParentKey());
         if (p != null) {
           p.setDraftCount(p.getDraftCount() + 1);

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

@@ -508,8 +508,8 @@ public class ChangeUtil {
     ReviewDb db = this.db.get();
     db.accountPatchReviews().delete(db.accountPatchReviews().byPatchSet(patchSetId));
     db.changeMessages().delete(db.changeMessages().byPatchSet(patchSetId));
-    db.patchComments().delete(db.patchComments().byPatchSet(patchSetId));
     // No need to delete from notedb; draft patch sets will be filtered out.
+    db.patchComments().delete(db.patchComments().byPatchSet(patchSetId));
     db.patchSetApprovals().delete(db.patchSetApprovals().byPatchSet(patchSetId));
     db.patchSetAncestors().delete(db.patchSetAncestors().byPatchSet(patchSetId));
 

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

@@ -12,25 +12,44 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-
 package com.google.gerrit.server;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Optional;
+import com.google.common.base.Predicate;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
+import com.google.gerrit.reviewdb.client.Account;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.PatchLineComment;
+import com.google.gerrit.reviewdb.client.RefNames;
 import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.RevId;
 import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.config.AllUsersName;
+import com.google.gerrit.server.config.AllUsersNameProvider;
+import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.notedb.ChangeNotes;
 import com.google.gerrit.server.notedb.ChangeUpdate;
+import com.google.gerrit.server.notedb.DraftCommentNotes;
 import com.google.gerrit.server.notedb.NotesMigration;
+import com.google.gerrit.server.patch.PatchList;
+import com.google.gerrit.server.patch.PatchListCache;
+import com.google.gerrit.server.patch.PatchListNotAvailableException;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.RefDatabase;
+import org.eclipse.jgit.lib.Repository;
+
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Utility functions to manipulate PatchLineComments.
@@ -40,45 +59,179 @@ import java.util.List;
  */
 @Singleton
 public class PatchLineCommentsUtil {
+  private final GitRepositoryManager repoManager;
+  private final AllUsersName allUsers;
+  private final DraftCommentNotes.Factory draftFactory;
   private final NotesMigration migration;
 
   @VisibleForTesting
   @Inject
-  public PatchLineCommentsUtil(NotesMigration migration) {
+  public PatchLineCommentsUtil(GitRepositoryManager repoManager,
+      AllUsersNameProvider allUsersProvider,
+      DraftCommentNotes.Factory draftFactory,
+      NotesMigration migration) {
+    this.repoManager = repoManager;
+    this.allUsers = allUsersProvider.get();
+    this.draftFactory = draftFactory;
     this.migration = migration;
   }
 
+  public Optional<PatchLineComment> get(ReviewDb db, ChangeNotes notes,
+      PatchLineComment.Key key) throws OrmException {
+    if (!migration.readComments()) {
+      return Optional.fromNullable(db.patchComments().get(key));
+    }
+    for (PatchLineComment c : byChange(db, notes)) {
+      if (key.equals(c.getKey())) {
+        return Optional.of(c);
+      }
+    }
+    return Optional.absent();
+  }
+
+  public List<PatchLineComment> byChange(ReviewDb db,
+      ChangeNotes notes) throws OrmException {
+    if (!migration.readComments()) {
+      return db.patchComments().byChange(notes.getChangeId()).toList();
+    }
+    notes.load();
+
+    List<PatchLineComment> comments = Lists.newArrayList();
+    comments.addAll(notes.getBaseComments().values());
+    comments.addAll(notes.getPatchSetComments().values());
+
+    Iterable<String> filtered = getDraftRefs(notes.getChangeId());
+    for (String refName : filtered) {
+      Account.Id account = Account.Id.fromRefPart(refName);
+      if (account != null) {
+        comments.addAll(draftByChangeAuthor(db, notes, account));
+      }
+    }
+    return comments;
+  }
+
+  public List<PatchLineComment> byPatchSet(ReviewDb db,
+      ChangeNotes notes, PatchSet.Id psId) throws OrmException {
+    if (!migration.readComments()) {
+      return db.patchComments().byPatchSet(psId).toList();
+    }
+    List<PatchLineComment> comments = Lists.newArrayList();
+    comments.addAll(publishedByPatchSet(db, notes, psId));
+
+    Iterable<String> filtered = getDraftRefs(notes.getChangeId());
+    for (String refName : filtered) {
+      Account.Id account = Account.Id.fromRefPart(refName);
+      if (account != null) {
+        comments.addAll(draftByPatchSetAuthor(db, psId, account, notes));
+      }
+    }
+    return comments;
+  }
+
   public List<PatchLineComment> publishedByChangeFile(ReviewDb db,
       ChangeNotes notes, Change.Id changeId, String file) throws OrmException {
-    if (!migration.readPublishedComments()) {
+    if (!migration.readComments()) {
       return db.patchComments().publishedByChangeFile(changeId, file).toList();
     }
     notes.load();
-    List<PatchLineComment> commentsOnFile = new ArrayList<PatchLineComment>();
+    List<PatchLineComment> comments = Lists.newArrayList();
 
-    // We must iterate through all comments to find the ones on this file.
+    addCommentsOnFile(comments, notes.getBaseComments().values(), file);
-    addCommentsInFile(commentsOnFile, notes.getBaseComments().values(), file);
+    addCommentsOnFile(comments, notes.getPatchSetComments().values(),
-    addCommentsInFile(commentsOnFile, notes.getPatchSetComments().values(),
         file);
-
+    Collections.sort(comments, ChangeNotes.PatchLineCommentComparator);
-    Collections.sort(commentsOnFile, ChangeNotes.PatchLineCommentComparator);
+    return comments;
-    return commentsOnFile;
   }
 
   public List<PatchLineComment> publishedByPatchSet(ReviewDb db,
       ChangeNotes notes, PatchSet.Id psId) throws OrmException {
-    if (!migration.readPublishedComments()) {
+    if (!migration.readComments()) {
       return db.patchComments().publishedByPatchSet(psId).toList();
     }
     notes.load();
-    List<PatchLineComment> commentsOnPs = new ArrayList<PatchLineComment>();
+    List<PatchLineComment> comments = new ArrayList<PatchLineComment>();
-    commentsOnPs.addAll(notes.getPatchSetComments().get(psId));
+    comments.addAll(notes.getPatchSetComments().get(psId));
-    commentsOnPs.addAll(notes.getBaseComments().get(psId));
+    comments.addAll(notes.getBaseComments().get(psId));
-    return commentsOnPs;
+    return comments;
   }
 
-  // TODO(yyonas): Delete drafts if they already existed.
+  public List<PatchLineComment> draftByPatchSetAuthor(ReviewDb db,
-  public void addPublishedComments(ReviewDb db, ChangeUpdate update,
+      PatchSet.Id psId, Account.Id author, ChangeNotes notes)
+      throws OrmException {
+    if (!migration.readComments()) {
+      return db.patchComments().draftByPatchSetAuthor(psId, author).toList();
+    }
+
+    List<PatchLineComment> comments = Lists.newArrayList();
+
+    comments.addAll(notes.getDraftBaseComments(author).row(psId).values());
+    comments.addAll(notes.getDraftPsComments(author).row(psId).values());
+    Collections.sort(comments, ChangeNotes.PatchLineCommentComparator);
+    return comments;
+  }
+
+  public List<PatchLineComment> draftByChangeFileAuthor(ReviewDb db,
+      ChangeNotes notes, String file, Account.Id author)
+      throws OrmException {
+    if (!migration.readComments()) {
+      return db.patchComments()
+          .draftByChangeFileAuthor(notes.getChangeId(), file, author)
+          .toList();
+    }
+    List<PatchLineComment> comments = Lists.newArrayList();
+    addCommentsOnFile(comments, notes.getDraftBaseComments(author).values(),
+        file);
+    addCommentsOnFile(comments, notes.getDraftPsComments(author).values(),
+        file);
+    Collections.sort(comments, ChangeNotes.PatchLineCommentComparator);
+    return comments;
+  }
+
+  public List<PatchLineComment> draftByChangeAuthor(ReviewDb db,
+      ChangeNotes notes, Account.Id author)
+      throws OrmException {
+    if (!migration.readComments()) {
+      return db.patchComments().byChange(notes.getChangeId()).toList();
+    }
+    List<PatchLineComment> comments = Lists.newArrayList();
+    comments.addAll(notes.getDraftBaseComments(author).values());
+    comments.addAll(notes.getDraftPsComments(author).values());
+    return comments;
+  }
+
+  public List<PatchLineComment> draftByAuthor(ReviewDb db,
+      Account.Id author) throws OrmException {
+    if (!migration.readComments()) {
+      return db.patchComments().draftByAuthor(author).toList();
+    }
+
+    Set<String> refNames =
+        getRefNamesAllUsers(RefNames.REFS_DRAFT_COMMENTS);
+
+    List<PatchLineComment> comments = Lists.newArrayList();
+    for (String refName : refNames) {
+      Account.Id id = Account.Id.fromRefPart(refName);
+      if (!author.equals(id)) {
+        continue;
+      }
+      Change.Id changeId = Change.Id.parse(refName);
+      DraftCommentNotes draftNotes =
+          draftFactory.create(changeId, author).load();
+      comments.addAll(draftNotes.getDraftBaseComments().values());
+      comments.addAll(draftNotes.getDraftPsComments().values());
+    }
+    return comments;
+  }
+
+  public void insertComments(ReviewDb db, ChangeUpdate update,
+      Iterable<PatchLineComment> comments) throws OrmException {
+    for (PatchLineComment c : comments) {
+      update.insertComment(c);
+    }
+    db.patchComments().insert(comments);
+  }
+
+  public void upsertComments(ReviewDb db, ChangeUpdate update,
       Iterable<PatchLineComment> comments) throws OrmException {
     for (PatchLineComment c : comments) {
       update.upsertComment(c);
@@ -86,7 +239,23 @@ public class PatchLineCommentsUtil {
     db.patchComments().upsert(comments);
   }
 
-  private static Collection<PatchLineComment> addCommentsInFile(
+  public void updateComments(ReviewDb db, ChangeUpdate update,
+      Iterable<PatchLineComment> comments) throws OrmException {
+    for (PatchLineComment c : comments) {
+      update.updateComment(c);
+    }
+    db.patchComments().update(comments);
+  }
+
+  public void deleteComments(ReviewDb db, ChangeUpdate update,
+      Iterable<PatchLineComment> comments) throws OrmException {
+    for (PatchLineComment c : comments) {
+      update.deleteComment(c);
+    }
+    db.patchComments().delete(comments);
+  }
+
+  private static Collection<PatchLineComment> addCommentsOnFile(
       Collection<PatchLineComment> commentsOnFile,
       Collection<PatchLineComment> allComments,
       String file) {
@@ -98,4 +267,49 @@ public class PatchLineCommentsUtil {
     }
     return commentsOnFile;
   }
+
+  public static void setCommentRevId(PatchLineComment c,
+      PatchListCache cache, Change change, PatchSet ps) throws OrmException {
+    if (c.getRevId() != null) {
+      return;
+    }
+    PatchList patchList;
+    try {
+      patchList = cache.get(change, ps);
+    } catch (PatchListNotAvailableException e) {
+      throw new OrmException(e);
+    }
+    c.setRevId((c.getSide() == (short) 0)
+      ? new RevId(ObjectId.toString(patchList.getOldId()))
+      : new RevId(ObjectId.toString(patchList.getNewId())));
+  }
+
+  private Set<String> getRefNamesAllUsers(String prefix) throws OrmException {
+    Repository repo;
+    try {
+      repo = repoManager.openRepository(allUsers);
+    } catch (IOException e) {
+      throw new OrmException(e);
+    }
+    try {
+      RefDatabase refDb = repo.getRefDatabase();
+      return refDb.getRefs(prefix).keySet();
+    } catch (IOException e) {
+      throw new OrmException(e);
+    } finally {
+      repo.close();
+    }
+  }
+
+  private Iterable<String> getDraftRefs(final Change.Id changeId)
+      throws OrmException {
+    Set<String> refNames = getRefNamesAllUsers(RefNames.REFS_DRAFT_COMMENTS);
+    final String suffix = "-" + changeId.get();
+    return Iterables.filter(refNames, new Predicate<String>() {
+      @Override
+      public boolean apply(String input) {
+        return input.endsWith(suffix);
+      }
+    });
+  }
 }

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

@@ -77,6 +77,7 @@ import com.google.gerrit.server.AnonymousUser;
 import com.google.gerrit.server.ChangeMessagesUtil;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.PatchLineCommentsUtil;
 import com.google.gerrit.server.WebLinks;
 import com.google.gerrit.server.account.AccountInfo;
 import com.google.gerrit.server.extensions.webui.UiActions;
@@ -127,6 +128,7 @@ public class ChangeJson {
   private final Provider<WebLinks> webLinks;
   private final EnumSet<ListChangesOption> options;
   private final ChangeMessagesUtil cmUtil;
+  private final PatchLineCommentsUtil plcUtil;
 
   private AccountInfo.Loader accountLoader;
 
@@ -147,7 +149,8 @@ public class ChangeJson {
       DynamicMap<RestView<ChangeResource>> changeViews,
       Revisions revisions,
       Provider<WebLinks> webLinks,
-      ChangeMessagesUtil cmUtil) {
+      ChangeMessagesUtil cmUtil,
+      PatchLineCommentsUtil plcUtil) {
     this.db = db;
     this.labelNormalizer = ln;
     this.userProvider = user;
@@ -163,6 +166,7 @@ public class ChangeJson {
     this.revisions = revisions;
     this.webLinks = webLinks;
     this.cmUtil = cmUtil;
+    this.plcUtil = plcUtil;
     options = EnumSet.noneOf(ListChangesOption.class);
   }
 
@@ -821,9 +825,8 @@ public class ChangeJson {
         && userProvider.get().isIdentifiedUser()) {
       IdentifiedUser user = (IdentifiedUser)userProvider.get();
       out.hasDraftComments =
-          db.get().patchComments()
+          plcUtil.draftByPatchSetAuthor(db.get(), in.getId(),
-              .draftByPatchSetAuthor(in.getId(), user.getAccountId())
+              user.getAccountId(), ctl.getNotes()).iterator().hasNext()
-              .iterator().hasNext()
           ? true
           : null;
     }

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

@@ -14,6 +14,8 @@
 
 package com.google.gerrit.server.change;
 
+import static com.google.gerrit.server.PatchLineCommentsUtil.setCommentRevId;
+
 import com.google.common.base.Strings;
 import com.google.gerrit.common.changes.Side;
 import com.google.gerrit.extensions.restapi.BadRequestException;
@@ -24,27 +26,41 @@ import com.google.gerrit.reviewdb.client.Patch;
 import com.google.gerrit.reviewdb.client.PatchLineComment;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.ChangeUtil;
+import com.google.gerrit.server.PatchLineCommentsUtil;
 import com.google.gerrit.server.change.PutDraft.Input;
+import com.google.gerrit.server.notedb.ChangeUpdate;
+import com.google.gerrit.server.patch.PatchListCache;
 import com.google.gerrit.server.util.TimeUtil;
 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.sql.Timestamp;
 import java.util.Collections;
 
 @Singleton
 class CreateDraft implements RestModifyView<RevisionResource, Input> {
   private final Provider<ReviewDb> db;
+  private final ChangeUpdate.Factory updateFactory;
+  private final PatchLineCommentsUtil plcUtil;
+  private final PatchListCache patchListCache;
 
   @Inject
-  CreateDraft(Provider<ReviewDb> db) {
+  CreateDraft(Provider<ReviewDb> db,
+      ChangeUpdate.Factory updateFactory,
+      PatchLineCommentsUtil plcUtil,
+      PatchListCache patchListCache) {
     this.db = db;
+    this.updateFactory = updateFactory;
+    this.plcUtil = plcUtil;
+    this.patchListCache = patchListCache;
   }
 
   @Override
   public Response<CommentInfo> apply(RevisionResource rsrc, Input in)
-      throws BadRequestException, OrmException {
+      throws BadRequestException, OrmException, IOException {
     if (Strings.isNullOrEmpty(in.path)) {
       throw new BadRequestException("path must be non-empty");
     } else if (in.message == null || in.message.trim().isEmpty()) {
@@ -59,15 +75,20 @@ class CreateDraft implements RestModifyView<RevisionResource, Input> {
         ? in.line
         : in.range != null ? in.range.getEndLine() : 0;
 
+    Timestamp now = TimeUtil.nowTs();
+    ChangeUpdate update = updateFactory.create(rsrc.getControl(), now);
+
     PatchLineComment c = new PatchLineComment(
         new PatchLineComment.Key(
             new Patch.Key(rsrc.getPatchSet().getId(), in.path),
             ChangeUtil.messageUUID(db.get())),
-        line, rsrc.getAccountId(), Url.decode(in.inReplyTo), TimeUtil.nowTs());
+        line, rsrc.getAccountId(), Url.decode(in.inReplyTo), now);
     c.setSide(in.side == Side.PARENT ? (short) 0 : (short) 1);
     c.setMessage(in.message.trim());
     c.setRange(in.range);
-    db.get().patchComments().insert(Collections.singleton(c));
+    setCommentRevId(c, patchListCache, rsrc.getChange(), rsrc.getPatchSet());
+    plcUtil.insertComments(db.get(), update, Collections.singleton(c));
+    update.commit();
     return Response.created(new CommentInfo(c, null));
   }
 }

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

@@ -14,15 +14,22 @@
 
 package com.google.gerrit.server.change;
 
+import static com.google.gerrit.server.PatchLineCommentsUtil.setCommentRevId;
+
 import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestModifyView;
+import com.google.gerrit.reviewdb.client.PatchLineComment;
 import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.PatchLineCommentsUtil;
 import com.google.gerrit.server.change.DeleteDraft.Input;
+import com.google.gerrit.server.notedb.ChangeUpdate;
+import com.google.gerrit.server.patch.PatchListCache;
 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;
 
 @Singleton
@@ -31,16 +38,30 @@ class DeleteDraft implements RestModifyView<DraftResource, Input> {
   }
 
   private final Provider<ReviewDb> db;
+  private final PatchLineCommentsUtil plcUtil;
+  private final ChangeUpdate.Factory updateFactory;
+  private final PatchListCache patchListCache;
 
   @Inject
-  DeleteDraft(Provider<ReviewDb> db) {
+  DeleteDraft(Provider<ReviewDb> db,
+      PatchLineCommentsUtil plcUtil,
+      ChangeUpdate.Factory updateFactory,
+      PatchListCache patchListCache) {
     this.db = db;
+    this.plcUtil = plcUtil;
+    this.updateFactory = updateFactory;
+    this.patchListCache = patchListCache;
   }
 
   @Override
   public Response<CommentInfo> apply(DraftResource rsrc, Input input)
-      throws OrmException {
+      throws OrmException, IOException {
-    db.get().patchComments().delete(Collections.singleton(rsrc.getComment()));
+    ChangeUpdate update = updateFactory.create(rsrc.getControl());
+
+    PatchLineComment c = rsrc.getComment();
+    setCommentRevId(c, patchListCache, rsrc.getChange(), rsrc.getPatchSet());
+    plcUtil.deleteComments(db.get(), update, Collections.singleton(c));
+    update.commit();
     return Response.none();
   }
 }

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

@@ -23,6 +23,7 @@ import com.google.gerrit.extensions.restapi.RestView;
 import com.google.gerrit.reviewdb.client.PatchLineComment;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.PatchLineCommentsUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
@@ -34,16 +35,19 @@ class Drafts implements ChildCollection<RevisionResource, DraftResource> {
   private final Provider<CurrentUser> user;
   private final ListDrafts list;
   private final Provider<ReviewDb> dbProvider;
+  private final PatchLineCommentsUtil plcUtil;
 
   @Inject
   Drafts(DynamicMap<RestView<DraftResource>> views,
       Provider<CurrentUser> user,
       ListDrafts list,
-      Provider<ReviewDb> dbProvider) {
+      Provider<ReviewDb> dbProvider,
+      PatchLineCommentsUtil plcUtil) {
     this.views = views;
     this.user = user;
     this.list = list;
     this.dbProvider = dbProvider;
+    this.plcUtil = plcUtil;
   }
 
   @Override
@@ -62,10 +66,8 @@ class Drafts implements ChildCollection<RevisionResource, DraftResource> {
       throws ResourceNotFoundException, OrmException, AuthException {
     checkIdentifiedUser();
     String uuid = id.get();
-    for (PatchLineComment c : dbProvider.get().patchComments()
+    for (PatchLineComment c : plcUtil.draftByPatchSetAuthor(dbProvider.get(),
-        .draftByPatchSetAuthor(
+        rev.getPatchSet().getId(), rev.getAccountId(), rev.getNotes())) {
-            rev.getPatchSet().getId(),
-            rev.getAccountId())) {
       if (uuid.equals(c.getKey().get())) {
         return new DraftResource(rev, c);
       }

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

@@ -26,13 +26,10 @@ import com.google.inject.Singleton;
 
 @Singleton
 class ListComments extends ListDrafts {
-  private final PatchLineCommentsUtil plcUtil;
-
   @Inject
   ListComments(Provider<ReviewDb> db, AccountInfo.Loader.Factory alf,
       PatchLineCommentsUtil plcUtil) {
-    super(db, alf);
+    super(db, alf, plcUtil);
-    this.plcUtil = plcUtil;
   }
 
   @Override

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

@@ -22,6 +22,7 @@ import com.google.gerrit.common.changes.Side;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.reviewdb.client.PatchLineComment;
 import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.PatchLineCommentsUtil;
 import com.google.gerrit.server.account.AccountInfo;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
@@ -36,20 +37,21 @@ import java.util.Map;
 @Singleton
 class ListDrafts implements RestReadView<RevisionResource> {
   protected final Provider<ReviewDb> db;
+  protected final PatchLineCommentsUtil plcUtil;
   private final AccountInfo.Loader.Factory accountLoaderFactory;
 
   @Inject
-  ListDrafts(Provider<ReviewDb> db, AccountInfo.Loader.Factory alf) {
+  ListDrafts(Provider<ReviewDb> db, AccountInfo.Loader.Factory alf,
+      PatchLineCommentsUtil plcUtil) {
     this.db = db;
     this.accountLoaderFactory = alf;
+    this.plcUtil = plcUtil;
   }
 
   protected Iterable<PatchLineComment> listComments(RevisionResource rsrc)
       throws OrmException {
-    return db.get().patchComments()
+    return plcUtil.draftByPatchSetAuthor(db.get(), rsrc.getPatchSet().getId(),
-        .draftByPatchSetAuthor(
+        rsrc.getAccountId(), rsrc.getNotes());
-            rsrc.getPatchSet().getId(),
-            rsrc.getAccountId());
   }
 
   protected boolean includeAuthorInfo() {

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

@@ -15,6 +15,7 @@
 package com.google.gerrit.server.change;
 
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.gerrit.server.PatchLineCommentsUtil.setCommentRevId;
 
 import com.google.common.base.Objects;
 import com.google.common.base.Strings;
@@ -44,7 +45,6 @@ import com.google.gerrit.reviewdb.client.CommentRange;
 import com.google.gerrit.reviewdb.client.Patch;
 import com.google.gerrit.reviewdb.client.PatchLineComment;
 import com.google.gerrit.reviewdb.client.PatchSetApproval;
-import com.google.gerrit.reviewdb.client.RevId;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.ApprovalsUtil;
 import com.google.gerrit.server.ChangeMessagesUtil;
@@ -54,9 +54,7 @@ import com.google.gerrit.server.PatchLineCommentsUtil;
 import com.google.gerrit.server.account.AccountsCollection;
 import com.google.gerrit.server.index.ChangeIndexer;
 import com.google.gerrit.server.notedb.ChangeUpdate;
-import com.google.gerrit.server.patch.PatchList;
 import com.google.gerrit.server.patch.PatchListCache;
-import com.google.gerrit.server.patch.PatchListNotAvailableException;
 import com.google.gerrit.server.project.ChangeControl;
 import com.google.gerrit.server.query.change.ChangeData;
 import com.google.gerrit.server.util.LabelVote;
@@ -65,7 +63,6 @@ import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 
-import org.eclipse.jgit.lib.ObjectId;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -346,15 +343,6 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
     List<PatchLineComment> del = Lists.newArrayList();
     List<PatchLineComment> ups = Lists.newArrayList();
 
-    PatchList patchList = null;
-    try {
-      patchList = patchListCache.get(rsrc.getChange(), rsrc.getPatchSet());
-    } catch (PatchListNotAvailableException e) {
-      throw new OrmException("could not load PatchList for this patchset", e);
-    }
-    RevId patchSetCommit = new RevId(ObjectId.toString(patchList.getNewId()));
-    RevId baseCommit = new RevId(ObjectId.toString(patchList.getOldId()));
-
     for (Map.Entry<String, List<CommentInput>> ent : in.entrySet()) {
       String path = ent.getKey();
       for (CommentInput c : ent.getValue()) {
@@ -374,7 +362,8 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
         e.setStatus(PatchLineComment.Status.PUBLISHED);
         e.setWrittenOn(timestamp);
         e.setSide(c.side == Side.PARENT ? (short) 0 : (short) 1);
-        e.setRevId(c.side == Side.PARENT ? baseCommit : patchSetCommit);
+        setCommentRevId(e, patchListCache, rsrc.getChange(),
+            rsrc.getPatchSet());
         e.setMessage(c.message);
         if (c.range != null) {
           e.setRange(new CommentRange(
@@ -398,13 +387,14 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
         for (PatchLineComment e : drafts.values()) {
           e.setStatus(PatchLineComment.Status.PUBLISHED);
           e.setWrittenOn(timestamp);
-          e.setRevId(e.getSide() == (short) 0 ? baseCommit : patchSetCommit);
+          setCommentRevId(e, patchListCache, rsrc.getChange(),
+              rsrc.getPatchSet());
           ups.add(e);
         }
         break;
     }
-    db.get().patchComments().delete(del);
+    plcUtil.deleteComments(db.get(), update, del);
-    plcUtil.addPublishedComments(db.get(), update, ups);
+    plcUtil.upsertComments(db.get(), update, ups);
     comments.addAll(ups);
     return !del.isEmpty() || !ups.isEmpty();
   }
@@ -412,9 +402,8 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
   private Map<String, PatchLineComment> scanDraftComments(
       RevisionResource rsrc) throws OrmException {
     Map<String, PatchLineComment> drafts = Maps.newHashMap();
-    for (PatchLineComment c : db.get().patchComments().draftByPatchSetAuthor(
+    for (PatchLineComment c : plcUtil.draftByPatchSetAuthor(db.get(),
-          rsrc.getPatchSet().getId(),
+        rsrc.getPatchSet().getId(), rsrc.getAccountId(), rsrc.getNotes())) {
-          rsrc.getAccountId())) {
       drafts.put(c.getKey().get(), c);
     }
     return drafts;

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

@@ -14,6 +14,8 @@
 
 package com.google.gerrit.server.change;
 
+import static com.google.gerrit.server.PatchLineCommentsUtil.setCommentRevId;
+
 import com.google.gerrit.common.changes.Side;
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.DefaultInput;
@@ -24,13 +26,17 @@ import com.google.gerrit.reviewdb.client.CommentRange;
 import com.google.gerrit.reviewdb.client.Patch;
 import com.google.gerrit.reviewdb.client.PatchLineComment;
 import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.PatchLineCommentsUtil;
 import com.google.gerrit.server.change.PutDraft.Input;
+import com.google.gerrit.server.notedb.ChangeUpdate;
+import com.google.gerrit.server.patch.PatchListCache;
 import com.google.gerrit.server.util.TimeUtil;
 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.sql.Timestamp;
 import java.util.Collections;
 
@@ -51,17 +57,28 @@ class PutDraft implements RestModifyView<DraftResource, Input> {
 
   private final Provider<ReviewDb> db;
   private final DeleteDraft delete;
+  private final PatchLineCommentsUtil plcUtil;
+  private final ChangeUpdate.Factory updateFactory;
+  private final PatchListCache patchListCache;
 
   @Inject
-  PutDraft(Provider<ReviewDb> db, DeleteDraft delete) {
+  PutDraft(Provider<ReviewDb> db,
+      DeleteDraft delete,
+      PatchLineCommentsUtil plcUtil,
+      ChangeUpdate.Factory updateFactory,
+      PatchListCache patchListCache) {
     this.db = db;
     this.delete = delete;
+    this.plcUtil = plcUtil;
+    this.updateFactory = updateFactory;
+    this.patchListCache = patchListCache;
   }
 
   @Override
   public Response<CommentInfo> apply(DraftResource rsrc, Input in) throws
-      BadRequestException, OrmException {
+      BadRequestException, OrmException, IOException {
     PatchLineComment c = rsrc.getComment();
+    ChangeUpdate update = updateFactory.create(rsrc.getControl());
     if (in == null || in.message == null || in.message.trim().isEmpty()) {
       return delete.apply(rsrc, null);
     } else if (in.id != null && !rsrc.getId().equals(in.id)) {
@@ -76,7 +93,8 @@ class PutDraft implements RestModifyView<DraftResource, Input> {
         && !in.path.equals(c.getKey().getParentKey().getFileName())) {
       // Updating the path alters the primary key, which isn't possible.
       // Delete then recreate the comment instead of an update.
-      db.get().patchComments().delete(Collections.singleton(c));
+
+      plcUtil.deleteComments(db.get(), update, Collections.singleton(c));
       c = new PatchLineComment(
           new PatchLineComment.Key(
               new Patch.Key(rsrc.getPatchSet().getId(), in.path),
@@ -84,10 +102,18 @@ class PutDraft implements RestModifyView<DraftResource, Input> {
           c.getLine(),
           rsrc.getAuthorId(),
           c.getParentUuid(), TimeUtil.nowTs());
-      db.get().patchComments().insert(Collections.singleton(update(c, in)));
+      setCommentRevId(c, patchListCache, rsrc.getChange(), rsrc.getPatchSet());
+      plcUtil.insertComments(db.get(), update,
+          Collections.singleton(update(c, in)));
     } else {
-      db.get().patchComments().update(Collections.singleton(update(c, in)));
+      if (c.getRevId() == null) {
+        setCommentRevId(c, patchListCache, rsrc.getChange(),
+            rsrc.getPatchSet());
+      }
+      plcUtil.updateComments(db.get(), update,
+          Collections.singleton(update(c, in)));
     }
+    update.commit();
     return Response.ok(new CommentInfo(c, null));
   }
 

gerrit-server/src/main/java/com/google/gerrit/server/mail/CommentSender.java

@@ -14,6 +14,7 @@
 
 package com.google.gerrit.server.mail;
 
+import com.google.common.base.Optional;
 import com.google.common.base.Strings;
 import com.google.common.collect.Ordering;
 import com.google.gerrit.common.errors.EmailException;
@@ -24,6 +25,7 @@ import com.google.gerrit.reviewdb.client.CommentRange;
 import com.google.gerrit.reviewdb.client.Patch;
 import com.google.gerrit.reviewdb.client.PatchLineComment;
 import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.server.PatchLineCommentsUtil;
 import com.google.gerrit.server.patch.PatchFile;
 import com.google.gerrit.server.patch.PatchList;
 import com.google.gerrit.server.patch.PatchListNotAvailableException;
@@ -53,13 +55,16 @@ public class CommentSender extends ReplyToChangeSender {
 
   private final NotifyHandling notify;
   private List<PatchLineComment> inlineComments = Collections.emptyList();
+  private final PatchLineCommentsUtil plcUtil;
 
   @Inject
   public CommentSender(EmailArguments ea,
       @Assisted NotifyHandling notify,
-      @Assisted Change c) {
+      @Assisted Change c,
+      PatchLineCommentsUtil plcUtil) {
     super(ea, c, "comment");
     this.notify = notify;
+    this.plcUtil = plcUtil;
   }
 
   public void setPatchLineComments(final List<PatchLineComment> plc)
@@ -232,17 +237,19 @@ public class CommentSender extends ReplyToChangeSender {
 
   private void appendQuotedParent(StringBuilder out, PatchLineComment child) {
     if (child.getParentUuid() != null) {
-      PatchLineComment parent;
+      Optional<PatchLineComment> parent;
+      PatchLineComment.Key key = new PatchLineComment.Key(
+          child.getKey().getParentKey(),
+          child.getParentUuid());
       try {
-        parent = args.db.get().patchComments().get(
+        parent = plcUtil.get(args.db.get(), changeData.notes(), key);
-            new PatchLineComment.Key(
-                child.getKey().getParentKey(),
-                child.getParentUuid()));
       } catch (OrmException e) {
-        parent = null;
+        log.warn("Could not find the parent of this comment: "
+            + child.toString());
+        parent = Optional.absent();
       }
-      if (parent != null) {
+      if (parent.isPresent()) {
-        String msg = parent.getMessage().trim();
+        String msg = parent.get().getMessage().trim();
         if (msg.length() > 75) {
           msg = msg.substring(0, 75);
         }

gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeDraftUpdate.java

@@ -105,9 +105,11 @@ public class ChangeDraftUpdate extends AbstractChangeUpdate {
     verifyComment(c);
     checkArgument(c.getStatus() == Status.DRAFT,
         "Cannot insert a published comment into a ChangeDraftUpdate");
-    checkArgument(!changeNotes.containsComment(c),
+    if (migration.readComments()) {
-        "A comment already exists with the same key,"
+      checkArgument(!changeNotes.containsComment(c),
-        + " so the following comment cannot be inserted: %s", c);
+          "A comment already exists with the same key,"
+          + " so the following comment cannot be inserted: %s", c);
+    }
     upsertComments.add(c);
   }
 
@@ -122,16 +124,32 @@ public class ChangeDraftUpdate extends AbstractChangeUpdate {
     verifyComment(c);
     checkArgument(c.getStatus() == Status.DRAFT,
         "Cannot update a published comment into a ChangeDraftUpdate");
-    checkArgument(draftNotes.containsComment(c),
+    // Here, we check to see if this comment existed previously as a draft.
-        "Cannot update this comment because it didn't exist previously");
+    // However, this could cause a race condition if there is a delete and an
+    // update operation happening concurrently (or two deletes) and they both
+    // believe that the comment exists. If a delete happens first, then
+    // the update will fail. However, this is an acceptable risk since the
+    // caller wanted the comment deleted anyways, so the end result will be the
+    // same either way.
+    if (migration.readComments()) {
+      checkArgument(draftNotes.containsComment(c),
+          "Cannot update this comment because it didn't exist previously");
+    }
     upsertComments.add(c);
   }
 
   public void deleteComment(PatchLineComment c) {
     verifyComment(c);
-    checkArgument(draftNotes.containsComment(c), "Cannot delete this comment"
+    // See the comment above about potential race condition.
-        + " because it didn't previously exist as a draft");
+    if (migration.readComments()) {
-    deleteComments.add(c);
+      checkArgument(draftNotes.containsComment(c), "Cannot delete this comment"
+          + " because it didn't previously exist as a draft");
+    }
+    if (migration.write()) {
+      if (draftNotes.containsComment(c)) {
+        deleteComments.add(c);
+      }
+    }
   }
 
   /**
@@ -151,7 +169,9 @@ public class ChangeDraftUpdate extends AbstractChangeUpdate {
     checkArgument(getCommentPsId(comment).equals(psId),
         "Comment on %s does not match configured patch set %s",
         getCommentPsId(comment), psId);
-    checkArgument(comment.getRevId() != null);
+    if (migration.write()) {
+      checkArgument(comment.getRevId() != null);
+    }
     checkArgument(comment.getAuthor().equals(accountId),
         "The author for the following comment does not match the author of"
         + " this ChangeDraftUpdate (%s): %s", accountId, comment);
@@ -174,6 +194,8 @@ public class ChangeDraftUpdate extends AbstractChangeUpdate {
     Table<PatchSet.Id, String, PatchLineComment> psDrafts =
         draftNotes.getDraftPsComments();
 
+    boolean draftsEmpty = baseDrafts.isEmpty() && psDrafts.isEmpty();
+
     // There is no need to rewrite the note for one of the sides of the patch
     // set if all of the modifications were made to the comments of one side,
     // so we set these flags to potentially save that extra work.
@@ -219,7 +241,8 @@ public class ChangeDraftUpdate extends AbstractChangeUpdate {
     updateNoteMap(revisionSideChanged, noteMap, newPsDrafts,
         psRevId);
 
-    removedAllComments.set(baseDrafts.isEmpty() && psDrafts.isEmpty());
+    removedAllComments.set(
+        baseDrafts.isEmpty() && psDrafts.isEmpty() && !draftsEmpty);
 
     return noteMap.writeTree(inserter);
   }

gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeUpdate.java

@@ -239,9 +239,11 @@ public class ChangeUpdate extends AbstractChangeUpdate {
     if (notes == null) {
       notes = getChangeNotes().load();
     }
-    checkArgument(!notes.containsComment(c),
+    if (migration.readComments()) {
-        "A comment already exists with the same key as the following comment,"
+      checkArgument(!notes.containsComment(c),
-        + " so we cannot insert this comment: %s", c);
+          "A comment already exists with the same key as the following comment,"
+          + " so we cannot insert this comment: %s", c);
+    }
     if (c.getSide() == 0) {
       commentsForBase.add(c);
     } else {
@@ -254,8 +256,19 @@ public class ChangeUpdate extends AbstractChangeUpdate {
     draftUpdate.insertComment(c);
   }
 
-  private void upsertPublishedComment(PatchLineComment c) {
+  private void upsertPublishedComment(PatchLineComment c) throws OrmException {
     verifyComment(c);
+    if (notes == null) {
+      notes = getChangeNotes().load();
+    }
+    // This could allow callers to update a published comment if migration.write
+    // is on and migration.readComments is off because we will not be able to
+    // verify that the comment didn't already exist as a published comment
+    // since we don't have a ReviewDb.
+    if (migration.readComments()) {
+      checkArgument(!notes.containsCommentPublished(c),
+          "Cannot update a comment that has already been published and saved");
+    }
     if (c.getSide() == 0) {
       commentsForBase.add(c);
     } else {
@@ -273,8 +286,12 @@ public class ChangeUpdate extends AbstractChangeUpdate {
     if (notes == null) {
       notes = getChangeNotes().load();
     }
-    checkArgument(!notes.containsCommentPublished(c),
+    // See comment above in upsertPublishedComment() about potential risk with
-        "Cannot update a comment that has already been published and saved");
+    // this check.
+    if (migration.readComments()) {
+      checkArgument(!notes.containsCommentPublished(c),
+          "Cannot update a comment that has already been published and saved");
+    }
     if (c.getSide() == 0) {
       commentsForBase.add(c);
     } else {
@@ -298,7 +315,6 @@ public class ChangeUpdate extends AbstractChangeUpdate {
     draftUpdate.deleteCommentIfPresent(c);
   }
 
-
   private void createDraftUpdateIfNull(PatchLineComment c) throws OrmException {
     if (draftUpdate == null) {
       draftUpdate = draftUpdateFactory.create(ctl, when);

gerrit-server/src/main/java/com/google/gerrit/server/notedb/NotesMigration.java

@@ -36,14 +36,14 @@ public class NotesMigration {
     cfg.setBoolean("notedb", null, "write", true);
     cfg.setBoolean("notedb", "patchSetApprovals", "read", true);
     cfg.setBoolean("notedb", "changeMessages", "read", true);
-    cfg.setBoolean("notedb", "publishedComments", "read", true);
+    cfg.setBoolean("notedb", "comments", "read", true);
     return new NotesMigration(cfg);
   }
 
   private final boolean write;
   private final boolean readPatchSetApprovals;
   private final boolean readChangeMessages;
-  private final boolean readPublishedComments;
+  private final boolean readComments;
 
   @Inject
   NotesMigration(@GerritServerConfig Config cfg) {
@@ -52,8 +52,8 @@ public class NotesMigration {
         cfg.getBoolean("notedb", "patchSetApprovals", "read", false);
     readChangeMessages =
         cfg.getBoolean("notedb", "changeMessages", "read", false);
-    readPublishedComments =
+    readComments =
-        cfg.getBoolean("notedb", "publishedComments", "read", false);
+        cfg.getBoolean("notedb", "comments", "read", false);
   }
 
   public boolean write() {
@@ -68,7 +68,7 @@ public class NotesMigration {
     return readChangeMessages;
   }
 
-  public boolean readPublishedComments() {
+  public boolean readComments() {
-    return readPublishedComments;
+    return readComments;
   }
 }

gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchScriptFactory.java

@@ -338,7 +338,8 @@ public class PatchScriptFactory implements Callable<PatchScript> {
   private void loadDrafts(final Map<Patch.Key, Patch> byKey,
       final AccountInfoCacheFactory aic, final Account.Id me, final String file)
       throws OrmException {
-    for (PatchLineComment c : db.patchComments().draftByChangeFileAuthor(changeId, file, me)) {
+    for (PatchLineComment c :
+        plcUtil.draftByChangeFileAuthor(db, control.getNotes(), file, me)) {
       if (comments.include(c)) {
         aic.want(me);
       }

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

@@ -30,7 +30,8 @@ public class BasicChangeRewrites extends QueryRewriter<ChangeData> {
           new InvalidProvider<ReviewDb>(), //
           new InvalidProvider<ChangeQueryRewriter>(), //
           null, null, null, null, null, null, null, //
-          null, null, null, null, null, null, null, null, null, null), null);
+          null, null, null, null, null, null, null, null, null, null, null),
+          null);
 
   private static final QueryRewriter.Definition<ChangeData, BasicChangeRewrites> mydef =
       new QueryRewriter.Definition<ChangeData, BasicChangeRewrites>(

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

@@ -35,6 +35,7 @@ import com.google.gerrit.server.ApprovalsUtil;
 import com.google.gerrit.server.ChangeMessagesUtil;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.PatchLineCommentsUtil;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.notedb.ChangeNotes;
 import com.google.gerrit.server.notedb.NotesMigration;
@@ -154,7 +155,7 @@ public class ChangeData {
    */
   static ChangeData createForTest(Change.Id id, int currentPatchSetId) {
     ChangeData cd = new ChangeData(null, null, null, null, null,
-        null, null, null, null, id);
+        null, null, null, null, null, id);
     cd.currentPatchSet = new PatchSet(new PatchSet.Id(id, currentPatchSetId));
     return cd;
   }
@@ -166,6 +167,7 @@ public class ChangeData {
   private final ChangeNotes.Factory notesFactory;
   private final ApprovalsUtil approvalsUtil;
   private final ChangeMessagesUtil cmUtil;
+  private final PatchLineCommentsUtil plcUtil;
   private final PatchListCache patchListCache;
   private final NotesMigration notesMigration;
   private final Change.Id legacyId;
@@ -194,6 +196,7 @@ public class ChangeData {
       ChangeNotes.Factory notesFactory,
       ApprovalsUtil approvalsUtil,
       ChangeMessagesUtil cmUtil,
+      PatchLineCommentsUtil plcUtil,
       PatchListCache patchListCache,
       NotesMigration notesMigration,
       @Assisted ReviewDb db,
@@ -205,6 +208,7 @@ public class ChangeData {
     this.notesFactory = notesFactory;
     this.approvalsUtil = approvalsUtil;
     this.cmUtil = cmUtil;
+    this.plcUtil = plcUtil;
     this.patchListCache = patchListCache;
     this.notesMigration = notesMigration;
     legacyId = id;
@@ -218,6 +222,7 @@ public class ChangeData {
       ChangeNotes.Factory notesFactory,
       ApprovalsUtil approvalsUtil,
       ChangeMessagesUtil cmUtil,
+      PatchLineCommentsUtil plcUtil,
       PatchListCache patchListCache,
       NotesMigration notesMigration,
       @Assisted ReviewDb db,
@@ -229,6 +234,7 @@ public class ChangeData {
     this.notesFactory = notesFactory;
     this.approvalsUtil = approvalsUtil;
     this.cmUtil = cmUtil;
+    this.plcUtil = plcUtil;
     this.patchListCache = patchListCache;
     this.notesMigration = notesMigration;
     legacyId = c.getId();
@@ -243,6 +249,7 @@ public class ChangeData {
       ChangeNotes.Factory notesFactory,
       ApprovalsUtil approvalsUtil,
       ChangeMessagesUtil cmUtil,
+      PatchLineCommentsUtil plcUtil,
       PatchListCache patchListCache,
       NotesMigration notesMigration,
       @Assisted ReviewDb db,
@@ -254,6 +261,7 @@ public class ChangeData {
     this.notesFactory = notesFactory;
     this.approvalsUtil = approvalsUtil;
     this.cmUtil = cmUtil;
+    this.plcUtil = plcUtil;
     this.patchListCache = patchListCache;
     this.notesMigration = notesMigration;
     legacyId = c.getChange().getId();
@@ -522,7 +530,7 @@ public class ChangeData {
   public Collection<PatchLineComment> comments()
       throws OrmException {
     if (comments == null) {
-      comments = db.patchComments().byChange(legacyId).toList();
+      comments = plcUtil.byChange(db, notes());
     }
     return comments;
   }

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

@@ -25,6 +25,7 @@ import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.PatchLineCommentsUtil;
 import com.google.gerrit.server.account.AccountResolver;
 import com.google.gerrit.server.account.CapabilityControl;
 import com.google.gerrit.server.account.GroupBackend;
@@ -146,6 +147,7 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
     final CapabilityControl.Factory capabilityControlFactory;
     final ChangeControl.GenericFactory changeControlGenericFactory;
     final ChangeData.Factory changeDataFactory;
+    final PatchLineCommentsUtil plcUtil;
     final AccountResolver accountResolver;
     final GroupBackend groupBackend;
     final AllProjectsName allProjectsName;
@@ -168,6 +170,7 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
         CapabilityControl.Factory capabilityControlFactory,
         ChangeControl.GenericFactory changeControlGenericFactory,
         ChangeData.Factory changeDataFactory,
+        PatchLineCommentsUtil plcUtil,
         AccountResolver accountResolver,
         GroupBackend groupBackend,
         AllProjectsName allProjectsName,
@@ -187,6 +190,7 @@ public class ChangeQueryBuilder extends QueryBuilder<ChangeData> {
       this.capabilityControlFactory = capabilityControlFactory;
       this.changeControlGenericFactory = changeControlGenericFactory;
       this.changeDataFactory = changeDataFactory;
+      this.plcUtil = plcUtil;
       this.accountResolver = accountResolver;
       this.groupBackend = groupBackend;
       this.allProjectsName = allProjectsName;

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

@@ -33,7 +33,8 @@ class HasDraftByPredicate extends OperatorPredicate<ChangeData> implements
   private final Arguments args;
   private final Account.Id accountId;
 
-  HasDraftByPredicate(Arguments args, Account.Id accountId) {
+  HasDraftByPredicate(Arguments args,
+      Account.Id accountId) {
     super(ChangeQueryBuilder.FIELD_DRAFTBY, accountId.toString());
     this.args = args;
     this.accountId = accountId;
@@ -41,20 +42,16 @@ class HasDraftByPredicate extends OperatorPredicate<ChangeData> implements
 
   @Override
   public boolean match(final ChangeData object) throws OrmException {
-    for (PatchLineComment c : object.comments()) {
+    return !args.plcUtil
-      if (c.getStatus() == PatchLineComment.Status.DRAFT
+        .draftByChangeAuthor(args.db.get(), object.notes(), accountId)
-          && c.getAuthor().equals(accountId)) {
+        .isEmpty();
-        return true;
-      }
-    }
-    return false;
   }
 
   @Override
   public ResultSet<ChangeData> read() throws OrmException {
     Set<Change.Id> ids = new HashSet<>();
-    for (PatchLineComment sc : args.db.get().patchComments()
+    for (PatchLineComment sc :
-        .draftByAuthor(accountId)) {
+        args.plcUtil.draftByAuthor(args.db.get(), accountId)) {
       ids.add(sc.getKey().getParentKey().getParentKey().getParentKey());
     }
 

gerrit-server/src/test/java/com/google/gerrit/server/change/CommentsTest.java

@@ -43,6 +43,7 @@ import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.RevId;
 import com.google.gerrit.reviewdb.server.PatchLineCommentAccess;
 import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
 import com.google.gerrit.server.PatchLineCommentsUtil;
@@ -60,7 +61,6 @@ import com.google.gerrit.server.git.GitModule;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.group.SystemGroupBackend;
 import com.google.gerrit.server.notedb.ChangeUpdate;
-import com.google.gerrit.server.notedb.NotesMigration;
 import com.google.gerrit.server.project.ChangeControl;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.util.TimeUtil;
@@ -74,6 +74,8 @@ import com.google.gwtorm.server.ResultSet;
 import com.google.inject.AbstractModule;
 import com.google.inject.Guice;
 import com.google.inject.Injector;
+import com.google.inject.Provides;
+import com.google.inject.Singleton;
 import com.google.inject.TypeLiteral;
 import com.google.inject.util.Providers;
 
@@ -104,7 +106,7 @@ public class CommentsTest  {
   public static @GerritServerConfig Config noteDbEnabled() {
     @GerritServerConfig Config cfg = new Config();
     cfg.setBoolean("notedb", null, "write", true);
-    cfg.setBoolean("notedb", "publishedComments", "read", true);
+    cfg.setBoolean("notedb", "comments", "read", true);
     return cfg;
   }
 
@@ -118,15 +120,23 @@ public class CommentsTest  {
   private PatchLineComment plc1;
   private PatchLineComment plc2;
   private PatchLineComment plc3;
+  private PatchLineComment plc4;
+  private PatchLineComment plc5;
   private IdentifiedUser changeOwner;
 
   @Before
   public void setUp() throws Exception {
     @SuppressWarnings("unchecked")
-    final DynamicMap<RestView<CommentResource>> views =
+    final DynamicMap<RestView<CommentResource>> commentViews =
         createMock(DynamicMap.class);
-    final TypeLiteral<DynamicMap<RestView<CommentResource>>> viewsType =
+    final TypeLiteral<DynamicMap<RestView<CommentResource>>> commentViewsType =
         new TypeLiteral<DynamicMap<RestView<CommentResource>>>() {};
+    @SuppressWarnings("unchecked")
+    final DynamicMap<RestView<DraftResource>> draftViews =
+        createMock(DynamicMap.class);
+    final TypeLiteral<DynamicMap<RestView<DraftResource>>> draftViewsType =
+        new TypeLiteral<DynamicMap<RestView<DraftResource>>>() {};
+
     final AccountInfo.Loader.Factory alf =
         createMock(AccountInfo.Loader.Factory.class);
     final ReviewDb db = createMock(ReviewDb.class);
@@ -139,10 +149,23 @@ public class CommentsTest  {
     @SuppressWarnings("unused")
     InMemoryRepository repo = repoManager.createRepository(project);
 
+    Account co = new Account(new Account.Id(1), TimeUtil.nowTs());
+    co.setFullName("Change Owner");
+    co.setPreferredEmail("change@owner.com");
+    accountCache.put(co);
+    final Account.Id ownerId = co.getId();
+
+    Account ou = new Account(new Account.Id(2), TimeUtil.nowTs());
+    ou.setFullName("Other Account");
+    ou.setPreferredEmail("other@account.com");
+    accountCache.put(ou);
+    Account.Id otherUserId = ou.getId();
+
     AbstractModule mod = new AbstractModule() {
       @Override
       protected void configure() {
-        bind(viewsType).toInstance(views);
+        bind(commentViewsType).toInstance(commentViews);
+        bind(draftViewsType).toInstance(draftViews);
         bind(AccountInfo.Loader.Factory.class).toInstance(alf);
         bind(ReviewDb.class).toProvider(Providers.<ReviewDb>of(db));
         bind(Config.class).annotatedWith(GerritServerConfig.class).toInstance(config);
@@ -162,28 +185,16 @@ public class CommentsTest  {
         bind(PersonIdent.class).annotatedWith(GerritPersonIdent.class)
           .toInstance(serverIdent);
       }
+
+      @Provides
+      @Singleton
+      CurrentUser getCurrentUser(IdentifiedUser.GenericFactory userFactory) {
+        return userFactory.create(ownerId);
+      }
     };
 
     injector = Guice.createInjector(mod);
 
-    NotesMigration migration = injector.getInstance(NotesMigration.class);
-    allUsers = injector.getInstance(AllUsersNameProvider.class);
-    repoManager.createRepository(allUsers.get());
-
-    plcUtil = new PatchLineCommentsUtil(migration);
-
-    Account co = new Account(new Account.Id(1), TimeUtil.nowTs());
-    co.setFullName("Change Owner");
-    co.setPreferredEmail("change@owner.com");
-    accountCache.put(co);
-    Account.Id ownerId = co.getId();
-
-    Account ou = new Account(new Account.Id(2), TimeUtil.nowTs());
-    ou.setFullName("Other Account");
-    ou.setPreferredEmail("other@account.com");
-    accountCache.put(ou);
-    Account.Id otherUserId = ou.getId();
-
     IdentifiedUser.GenericFactory userFactory =
         injector.getInstance(IdentifiedUser.GenericFactory.class);
     changeOwner = userFactory.create(ownerId);
@@ -199,6 +210,10 @@ public class CommentsTest  {
     expect(alf.create(true)).andReturn(accountLoader).anyTimes();
     replay(accountLoader, alf);
 
+    allUsers = injector.getInstance(AllUsersNameProvider.class);
+    repoManager.createRepository(allUsers.get());
+    plcUtil = injector.getInstance(PatchLineCommentsUtil.class);
+
     PatchLineCommentAccess plca = createMock(PatchLineCommentAccess.class);
     expect(db.patchComments()).andReturn(plca).anyTimes();
 
@@ -221,32 +236,54 @@ public class CommentsTest  {
         "FileOne.txt", Side.PARENT, 3, ownerId, timeBase + 2000,
         "First Parent Comment",  new CommentRange(1, 2, 3, 4));
     plc3.setRevId(new RevId("CDEFCDEFCDEFCDEFCDEFCDEFCDEFCDEFCDEFCDEF"));
+    plc4 = newPatchLineComment(psId2, "Comment4", null, "FileOne.txt",
+        Side.REVISION, 3, ownerId, timeBase + 3000, "Second Comment",
+        new CommentRange(1, 2, 3, 4), Status.DRAFT);
+    plc4.setRevId(new RevId("BCDEBCDEBCDEBCDEBCDEBCDEBCDEBCDEBCDEBCDE"));
+    plc5 = newPatchLineComment(psId2, "Comment5", null, "FileOne.txt",
+        Side.REVISION, 5, ownerId, timeBase + 4000, "Third Comment",
+        new CommentRange(3, 4, 5, 6), Status.DRAFT);
+    plc5.setRevId(new RevId("BCDEBCDEBCDEBCDEBCDEBCDEBCDEBCDEBCDEBCDE"));
 
     List<PatchLineComment> commentsByOwner = Lists.newArrayList();
     commentsByOwner.add(plc1);
     commentsByOwner.add(plc3);
     List<PatchLineComment> commentsByReviewer = Lists.newArrayList();
     commentsByReviewer.add(plc2);
+    List<PatchLineComment> drafts = Lists.newArrayList();
+    drafts.add(plc4);
+    drafts.add(plc5);
 
     plca.upsert(commentsByOwner);
     expectLastCall().anyTimes();
     plca.upsert(commentsByReviewer);
     expectLastCall().anyTimes();
+    plca.upsert(drafts);
+    expectLastCall().anyTimes();
 
     expect(plca.publishedByPatchSet(psId1))
         .andAnswer(results(plc1, plc2, plc3)).anyTimes();
     expect(plca.publishedByPatchSet(psId2))
         .andAnswer(results()).anyTimes();
+    expect(plca.draftByPatchSetAuthor(psId1, ownerId))
+        .andAnswer(results()).anyTimes();
+    expect(plca.draftByPatchSetAuthor(psId2, ownerId))
+        .andAnswer(results(plc4, plc5)).anyTimes();
     replay(db, plca);
 
     ChangeUpdate update = newUpdate(change, changeOwner);
     update.setPatchSetId(psId1);
-    plcUtil.addPublishedComments(db, update, commentsByOwner);
+    plcUtil.upsertComments(db, update, commentsByOwner);
     update.commit();
 
     update = newUpdate(change, otherUser);
     update.setPatchSetId(psId1);
-    plcUtil.addPublishedComments(db, update, commentsByReviewer);
+    plcUtil.upsertComments(db, update, commentsByReviewer);
+    update.commit();
+
+    update = newUpdate(change, changeOwner);
+    update.setPatchSetId(psId2);
+    plcUtil.upsertComments(db, update, drafts);
     update.commit();
 
     ChangeControl ctl = stubChangeControl(change);
@@ -286,6 +323,17 @@ public class CommentsTest  {
     assertGetComment(injector, revRes1, null, "BadComment");
   }
 
+  @Test
+  public void testListDrafts() throws Exception {
+    // test ListDrafts for patch set 1
+    assertListDrafts(injector, revRes1,
+        Collections.<String, ArrayList<PatchLineComment>> emptyMap());
+
+    // test ListDrafts for patch set 2
+    assertListDrafts(injector, revRes2, ImmutableMap.of(
+        "FileOne.txt", Lists.newArrayList(plc4, plc5)));
+  }
+
   private static IAnswer<ResultSet<PatchLineComment>> results(
       final PatchLineComment... comments) {
     return new IAnswer<ResultSet<PatchLineComment>>() {
@@ -305,7 +353,7 @@ public class CommentsTest  {
         fail("Expected no comment");
       }
       CommentInfo actual = getComment.apply(commentRes);
-      assertComment(expected, actual);
+      assertComment(expected, actual, true);
     } catch (ResourceNotFoundException e) {
       if (expected != null) {
         fail("Expected to find comment");
@@ -330,17 +378,42 @@ public class CommentsTest  {
       assertNotNull(actualComments);
       assertEquals(expectedComments.size(), actualComments.size());
       for (int i = 0; i < expectedComments.size(); i++) {
-        assertComment(expectedComments.get(i), actualComments.get(i));
+        assertComment(expectedComments.get(i), actualComments.get(i), true);
       }
     }
   }
 
-  private static void assertComment(PatchLineComment plc, CommentInfo ci) {
+  private static void assertListDrafts(Injector inj, RevisionResource res,
+      Map<String, ArrayList<PatchLineComment>> expected) throws Exception {
+    Drafts drafts = inj.getInstance(Drafts.class);
+    RestReadView<RevisionResource> listView =
+        (RestReadView<RevisionResource>) drafts.list();
+    @SuppressWarnings("unchecked")
+    Map<String, List<CommentInfo>> actual =
+        (Map<String, List<CommentInfo>>) listView.apply(res);
+    assertNotNull(actual);
+    assertEquals(expected.size(), actual.size());
+    assertEquals(expected.keySet(), actual.keySet());
+    for (Map.Entry<String, ArrayList<PatchLineComment>> entry : expected.entrySet()) {
+      List<PatchLineComment> expectedComments = entry.getValue();
+      List<CommentInfo> actualComments = actual.get(entry.getKey());
+      assertNotNull(actualComments);
+      assertEquals(expectedComments.size(), actualComments.size());
+      for (int i = 0; i < expectedComments.size(); i++) {
+        assertComment(expectedComments.get(i), actualComments.get(i), false);
+      }
+    }
+  }
+
+  private static void assertComment(PatchLineComment plc, CommentInfo ci,
+      boolean isPublished) {
     assertEquals(plc.getKey().get(), ci.id);
     assertEquals(plc.getParentUuid(), ci.inReplyTo);
     assertEquals(plc.getMessage(), ci.message);
-    assertNotNull(ci.author);
+    if (isPublished) {
-    assertEquals(plc.getAuthor(), ci.author._id);
+      assertNotNull(ci.author);
+      assertEquals(plc.getAuthor(), ci.author._id);
+    }
     assertEquals(plc.getLine(), (int) ci.line);
     assertEquals(plc.getSide() == 0 ? Side.PARENT : Side.REVISION,
         Objects.firstNonNull(ci.side, Side.REVISION));
@@ -351,7 +424,8 @@ public class CommentsTest  {
 
   private static PatchLineComment newPatchLineComment(PatchSet.Id psId,
       String uuid, String inReplyToUuid, String filename, Side side, int line,
-      Account.Id authorId, long millis, String message, CommentRange range) {
+      Account.Id authorId, long millis, String message, CommentRange range,
+      PatchLineComment.Status status) {
     Patch.Key p = new Patch.Key(psId, filename);
     PatchLineComment.Key id = new PatchLineComment.Key(p, uuid);
     PatchLineComment plc =
@@ -359,8 +433,15 @@ public class CommentsTest  {
     plc.setMessage(message);
     plc.setRange(range);
     plc.setSide(side == Side.PARENT ? (short) 0 : (short) 1);
-    plc.setStatus(Status.PUBLISHED);
+    plc.setStatus(status);
     plc.setWrittenOn(new Timestamp(millis));
     return plc;
   }
+
+  private static PatchLineComment newPatchLineComment(PatchSet.Id psId,
+      String uuid, String inReplyToUuid, String filename, Side side, int line,
+      Account.Id authorId, long millis, String message, CommentRange range) {
+    return newPatchLineComment(psId, uuid, inReplyToUuid, filename, side, line,
+        authorId, millis, message, range, Status.PUBLISHED);
+  }
 }

gerrit-server/src/test/java/com/google/gerrit/server/index/FakeQueryBuilder.java

@@ -26,8 +26,8 @@ public class FakeQueryBuilder extends ChangeQueryBuilder {
         new FakeQueryBuilder.Definition<>(
           FakeQueryBuilder.class),
         new ChangeQueryBuilder.Arguments(null, null, null, null, null, null,
-          null, null, null, null, null, null, null, null, indexes, null, null,
+          null, null, null, null, null, null, null, null, null, indexes, null,
-          null, null),
+          null, null, null),
         null);
   }
 

gerrit-server/src/test/java/com/google/gerrit/server/notedb/ChangeNotesTest.java

@@ -895,7 +895,9 @@ public class ChangeNotesTest {
   public void patchLineCommentNotesFormatSide1() throws Exception {
     Change c = newChange();
     ChangeUpdate update = newUpdate(c, otherUser);
-    String uuid = "uuid";
+    String uuid1 = "uuid1";
+    String uuid2 = "uuid2";
+    String uuid3 = "uuid3";
     String message1 = "comment 1";
     String message2 = "comment 2";
     String message3 = "comment 3";
@@ -906,7 +908,7 @@ public class ChangeNotesTest {
     PatchSet.Id psId = c.currentPatchSetId();
 
     PatchLineComment comment1 = newPublishedPatchLineComment(psId, "file1",
-        uuid, range1, range1.getEndLine(), otherUser, null, time1, message1,
+        uuid1, range1, range1.getEndLine(), otherUser, null, time1, message1,
         (short) 1, "abcd1234abcd1234abcd1234abcd1234abcd1234");
     update.setPatchSetId(psId);
     update.upsertComment(comment1);
@@ -915,7 +917,7 @@ public class ChangeNotesTest {
     update = newUpdate(c, otherUser);
     CommentRange range2 = new CommentRange(2, 1, 3, 1);
     PatchLineComment comment2 = newPublishedPatchLineComment(psId, "file1",
-        uuid, range2, range2.getEndLine(), otherUser, null, time2, message2,
+        uuid2, range2, range2.getEndLine(), otherUser, null, time2, message2,
         (short) 1, "abcd1234abcd1234abcd1234abcd1234abcd1234");
     update.setPatchSetId(psId);
     update.upsertComment(comment2);
@@ -924,7 +926,7 @@ public class ChangeNotesTest {
     update = newUpdate(c, otherUser);
     CommentRange range3 = new CommentRange(3, 1, 4, 1);
     PatchLineComment comment3 = newPublishedPatchLineComment(psId, "file2",
-        uuid, range3, range3.getEndLine(), otherUser, null, time3, message3,
+        uuid3, range3, range3.getEndLine(), otherUser, null, time3, message3,
         (short) 1, "abcd1234abcd1234abcd1234abcd1234abcd1234");
     update.setPatchSetId(psId);
     update.upsertComment(comment3);
@@ -948,14 +950,14 @@ public class ChangeNotesTest {
         + "1:1-2:1\n"
         + CommentsInNotesUtil.formatTime(serverIdent, time1) + "\n"
         + "Author: Other Account <2@gerrit>\n"
-        + "UUID: uuid\n"
+        + "UUID: uuid1\n"
         + "Bytes: 9\n"
         + "comment 1\n"
         + "\n"
         + "2:1-3:1\n"
         + CommentsInNotesUtil.formatTime(serverIdent, time2) + "\n"
         + "Author: Other Account <2@gerrit>\n"
-        + "UUID: uuid\n"
+        + "UUID: uuid2\n"
         + "Bytes: 9\n"
         + "comment 2\n"
         + "\n"
@@ -964,7 +966,7 @@ public class ChangeNotesTest {
         + "3:1-4:1\n"
         + CommentsInNotesUtil.formatTime(serverIdent, time3) + "\n"
         + "Author: Other Account <2@gerrit>\n"
-        + "UUID: uuid\n"
+        + "UUID: uuid3\n"
         + "Bytes: 9\n"
         + "comment 3\n"
         + "\n",
@@ -975,7 +977,8 @@ public class ChangeNotesTest {
   public void patchLineCommentNotesFormatSide0() throws Exception {
     Change c = newChange();
     ChangeUpdate update = newUpdate(c, otherUser);
-    String uuid = "uuid";
+    String uuid1 = "uuid1";
+    String uuid2 = "uuid2";
     String message1 = "comment 1";
     String message2 = "comment 2";
     CommentRange range1 = new CommentRange(1, 1, 2, 1);
@@ -984,7 +987,7 @@ public class ChangeNotesTest {
     PatchSet.Id psId = c.currentPatchSetId();
 
     PatchLineComment comment1 = newPublishedPatchLineComment(psId, "file1",
-        uuid, range1, range1.getEndLine(), otherUser, null, time1, message1,
+        uuid1, range1, range1.getEndLine(), otherUser, null, time1, message1,
         (short) 0, "abcd1234abcd1234abcd1234abcd1234abcd1234");
     update.setPatchSetId(psId);
     update.upsertComment(comment1);
@@ -993,7 +996,7 @@ public class ChangeNotesTest {
     update = newUpdate(c, otherUser);
     CommentRange range2 = new CommentRange(2, 1, 3, 1);
     PatchLineComment comment2 = newPublishedPatchLineComment(psId, "file1",
-        uuid, range2, range2.getEndLine(), otherUser, null, time2, message2,
+        uuid2, range2, range2.getEndLine(), otherUser, null, time2, message2,
         (short) 0, "abcd1234abcd1234abcd1234abcd1234abcd1234");
     update.setPatchSetId(psId);
     update.upsertComment(comment2);
@@ -1017,14 +1020,14 @@ public class ChangeNotesTest {
         + "1:1-2:1\n"
         + CommentsInNotesUtil.formatTime(serverIdent, time1) + "\n"
         + "Author: Other Account <2@gerrit>\n"
-        + "UUID: uuid\n"
+        + "UUID: uuid1\n"
         + "Bytes: 9\n"
         + "comment 1\n"
         + "\n"
         + "2:1-3:1\n"
         + CommentsInNotesUtil.formatTime(serverIdent, time2) + "\n"
         + "Author: Other Account <2@gerrit>\n"
-        + "UUID: uuid\n"
+        + "UUID: uuid2\n"
         + "Bytes: 9\n"
         + "comment 2\n"
         + "\n",
@@ -1037,7 +1040,8 @@ public class ChangeNotesTest {
       throws Exception {
     Change c = newChange();
     ChangeUpdate update = newUpdate(c, otherUser);
-    String uuid = "uuid";
+    String uuid1 = "uuid1";
+    String uuid2 = "uuid2";
     String messageForBase = "comment for base";
     String messageForPS = "comment for ps";
     CommentRange range = new CommentRange(1, 1, 2, 1);
@@ -1045,7 +1049,7 @@ public class ChangeNotesTest {
     PatchSet.Id psId = c.currentPatchSetId();
 
     PatchLineComment commentForBase =
-        newPublishedPatchLineComment(psId, "filename", uuid,
+        newPublishedPatchLineComment(psId, "filename", uuid1,
         range, range.getEndLine(), otherUser, null, now, messageForBase,
         (short) 0, "abcd1234abcd1234abcd1234abcd1234abcd1234");
     update.setPatchSetId(psId);
@@ -1054,7 +1058,7 @@ public class ChangeNotesTest {
 
     update = newUpdate(c, otherUser);
     PatchLineComment commentForPS =
-        newPublishedPatchLineComment(psId, "filename", uuid,
+        newPublishedPatchLineComment(psId, "filename", uuid2,
         range, range.getEndLine(), otherUser, null, now, messageForPS,
         (short) 1, "abcd4567abcd4567abcd4567abcd4567abcd4567");
     update.setPatchSetId(psId);
@@ -1078,7 +1082,8 @@ public class ChangeNotesTest {
   @Test
   public void patchLineCommentMultipleOnePatchsetOneFile() throws Exception {
     Change c = newChange();
-    String uuid = "uuid";
+    String uuid1 = "uuid1";
+    String uuid2 = "uuid2";
     CommentRange range = new CommentRange(1, 1, 2, 1);
     PatchSet.Id psId = c.currentPatchSetId();
     String filename = "filename";
@@ -1088,7 +1093,7 @@ public class ChangeNotesTest {
     Timestamp timeForComment1 = TimeUtil.nowTs();
     Timestamp timeForComment2 = TimeUtil.nowTs();
     PatchLineComment comment1 = newPublishedPatchLineComment(psId, filename,
-        uuid, range, range.getEndLine(), otherUser, null, timeForComment1,
+        uuid1, range, range.getEndLine(), otherUser, null, timeForComment1,
         "comment 1", side, "abcd1234abcd1234abcd1234abcd1234abcd1234");
     update.setPatchSetId(psId);
     update.upsertComment(comment1);
@@ -1096,7 +1101,7 @@ public class ChangeNotesTest {
 
     update = newUpdate(c, otherUser);
     PatchLineComment comment2 = newPublishedPatchLineComment(psId, filename,
-        uuid, range, range.getEndLine(), otherUser, null, timeForComment2,
+        uuid2, range, range.getEndLine(), otherUser, null, timeForComment2,
         "comment 2", side, "abcd1234abcd1234abcd1234abcd1234abcd1234");
     update.setPatchSetId(psId);
     update.upsertComment(comment2);