Merge changes Ibe956014,I4222b894,Iac4ea144,I803717e8,I39e97dcd, ... * changes: Support updating multiple VersionedMetaDatas in a BatchRefUpdate Refactor byChange() into two methods: drafts and published Add draft comments to PatchLineCommentsUtil Fix bug for comments with no range Resolve issue with naming of drafts ref Add method to parse an AccountId out of a RefName Improve PatchSet.Id.fromRef performance and avoid double-parsing

diff --git a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/server/change/CommentsIT.java b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/server/change/CommentsIT.java
new file mode 100644
index 0000000..9de5220
--- /dev/null
+++ b/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;
+  }
+}

diff --git a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/rpc/changedetail/PatchSetDetailFactory.java b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/rpc/changedetail/PatchSetDetailFactory.java
index 73cc83a..4a673cb 100644
--- a/gerrit-httpd/src/main/java/com/google/gerrit/httpd/rpc/changedetail/PatchSetDetailFactory.java
+++ b/gerrit-httpd/src/main/java/com/google/gerrit/httpd/rpc/changedetail/PatchSetDetailFactory.java

@@ -170,7 +170,8 @@
       // 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);

diff --git a/gerrit-reviewdb/BUCK b/gerrit-reviewdb/BUCK
index faf80a8..9b1991b 100644
--- a/gerrit-reviewdb/BUCK
+++ b/gerrit-reviewdb/BUCK

@@ -1,4 +1,5 @@
 SRC = 'src/main/java/com/google/gerrit/reviewdb/'
+TESTS = 'src/test/java/com/google/gerrit/reviewdb/'
 
 gwt_module(
   name = 'client',
@@ -22,3 +23,15 @@
   ],
   visibility = ['PUBLIC'],
 )
+
+java_test(
+  name = 'client_tests',
+  srcs = glob([TESTS + 'client/**/*.java']),
+  deps = [
+    ':client',
+    '//lib:gwtorm',
+    '//lib:junit',
+  ],
+  source_under_test = [':client'],
+  visibility = ['//tools/eclipse:classpath'],
+)

diff --git a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/Account.java b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/Account.java
index e131f7a..3d156f9 100644
--- a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/Account.java
+++ b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/Account.java

@@ -104,6 +104,55 @@
       r.fromString(str);
       return r;
     }
+
+    /**
+     * Parse an Account.Id out of a part of a ref-name.
+     *
+     * @param name  a ref name with the following syntax: {@code "34/1234..."}.
+     *              We assume that the caller has trimmed any prefix.
+     */
+    public static Id fromRefPart(String name) {
+      if (name == null) {
+        return null;
+      }
+
+      String[] parts = name.split("/");
+      int n = parts.length;
+      if (n < 2) {
+        return null;
+      }
+
+      // Last 2 digits.
+      int le;
+      for (le = 0; le < parts[0].length(); le++) {
+        if (!Character.isDigit(parts[0].charAt(le))) {
+          return null;
+        }
+      }
+      if (le != 2) {
+        return null;
+      }
+
+      // Full ID.
+      int ie;
+      for (ie = 0; ie < parts[1].length(); ie++) {
+        if (!Character.isDigit(parts[1].charAt(ie))) {
+          if (ie == 0) {
+            return null;
+          } else {
+            break;
+          }
+        }
+      }
+
+      int shard = Integer.parseInt(parts[0]);
+      int id = Integer.parseInt(parts[1].substring(0, ie));
+
+      if (id % 100 != shard) {
+        return null;
+      }
+      return new Account.Id(id);
+    }
   }
 
   @Column(id = 1)

diff --git a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/PatchSet.java b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/PatchSet.java
index 613978a..ed4d999 100644
--- a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/PatchSet.java
+++ b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/PatchSet.java

@@ -24,28 +24,8 @@
 /** A single revision of a {@link Change}. */
 public final class PatchSet {
   /** Is the reference name a change reference? */
-  public static boolean isRef(final String name) {
-    if (name == null || !name.startsWith(REFS_CHANGES)) {
-      return false;
-    }
-    boolean accepted = false;
-    int numsFound = 0;
-    for (int i = name.length() - 1; i >= REFS_CHANGES.length() - 1; i--) {
-      char c = name.charAt(i);
-      if (c >= '0' && c <= '9') {
-        accepted = (c != '0');
-      } else if (c == '/') {
-        if (accepted) {
-          if (++numsFound == 2) {
-            return true;
-          }
-          accepted = false;
-        }
-      } else {
-        return false;
-      }
-    }
-    return false;
+  public static boolean isRef(String name) {
+    return Id.fromRef(name) != null;
   }
 
   public static class Id extends IntKey<Change.Id> {
@@ -106,16 +86,63 @@
 
     /** Parse a PatchSet.Id from a {@link PatchSet#getRefName()} result. */
     public static Id fromRef(String name) {
-      if (!name.startsWith(REFS_CHANGES)) {
-        throw new IllegalArgumentException("Not a PatchSet.Id: " + name);
+      if (name == null || !name.startsWith(REFS_CHANGES)) {
+        return null;
       }
-      final String[] parts = name.substring(REFS_CHANGES.length()).split("/");
-      final int n = parts.length;
-      if (n < 2) {
-        throw new IllegalArgumentException("Not a PatchSet.Id: " + name);
+
+      // Last 2 digits.
+      int ls = REFS_CHANGES.length();
+      int le;
+      for (le = ls; le < name.length() && name.charAt(le) != '/'; le++) {
+        if (name.charAt(le) < '0' || name.charAt(le) > '9') {
+          return null;
+        }
       }
-      final int changeId = Integer.parseInt(parts[n - 2]);
-      final int patchSetId = Integer.parseInt(parts[n - 1]);
+      if (le - ls != 2) {
+        return null;
+      }
+
+      // Change ID.
+      int cs = le + 1;
+      if (cs >= name.length() || name.charAt(cs) == '0') {
+        return null;
+      }
+      int ce;
+      for (ce = cs; ce < name.length() && name.charAt(ce) != '/'; ce++) {
+        if (name.charAt(ce) < '0' || name.charAt(ce) > '9') {
+          return null;
+        }
+      }
+      switch (ce - cs) {
+        case 0:
+          return null;
+        case 1:
+          if (name.charAt(ls) != '0'
+              || name.charAt(ls + 1) != name.charAt(cs)) {
+            return null;
+          }
+          break;
+        default:
+          if (name.charAt(ls) != name.charAt(ce - 2)
+              || name.charAt(ls + 1) != name.charAt(ce - 1)) {
+            return null;
+          }
+          break;
+      }
+
+      // Patch set ID.
+      int ps = ce + 1;
+      if (ps >= name.length() || name.charAt(ps) == '0') {
+        return null;
+      }
+      for (int i = ps; i < name.length(); i++) {
+        if (name.charAt(i) < '0' || name.charAt(i) > '9') {
+          return null;
+        }
+      }
+
+      int changeId = Integer.parseInt(name.substring(cs, ce));
+      int patchSetId = Integer.parseInt(name.substring(ps));
       return new PatchSet.Id(new Change.Id(changeId), patchSetId);
     }
   }

diff --git a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/RefNames.java b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/RefNames.java
index 06e1803..390295f 100644
--- a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/RefNames.java
+++ b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/RefNames.java

@@ -31,6 +31,8 @@
   /** Configurations of project-specific dashboards (canned search queries). */
   public static final String REFS_DASHBOARDS = "refs/meta/dashboards/";
 
+  public static final String REFS_DRAFT_COMMENTS = "refs/draft-comments/";
+
   /**
    * Prefix applied to merge commit base nodes.
    * <p>
@@ -43,8 +45,6 @@
    */
   public static final String REFS_CACHE_AUTOMERGE = "refs/cache-automerge/";
 
-  public static final String REFS_DRAFT_PREFIX = "comments-";
-
   public static String refsUsers(Account.Id accountId) {
     StringBuilder r = new StringBuilder();
     r.append(REFS_USER);
@@ -62,9 +62,15 @@
   public static String refsDraftComments(Account.Id accountId,
       Change.Id changeId) {
     StringBuilder r = new StringBuilder();
-    r.append(refsUsers(accountId));
+    r.append(REFS_DRAFT_COMMENTS);
+    int n = accountId.get() % 100;
+    if (n < 10) {
+      r.append('0');
+    }
+    r.append(n);
     r.append('/');
-    r.append(REFS_DRAFT_PREFIX);
+    r.append(accountId.get());
+    r.append('-');
     r.append(changeId.get());
     return r.toString();
   }

diff --git a/gerrit-reviewdb/src/test/java/com/google/gerrit/reviewdb/client/AccountTest.java b/gerrit-reviewdb/src/test/java/com/google/gerrit/reviewdb/client/AccountTest.java
new file mode 100644
index 0000000..3ffdb92
--- /dev/null
+++ b/gerrit-reviewdb/src/test/java/com/google/gerrit/reviewdb/client/AccountTest.java

@@ -0,0 +1,55 @@
+// 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.reviewdb.client;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import com.google.gerrit.reviewdb.client.Account;
+
+import org.junit.Test;
+
+public class AccountTest {
+  @Test
+  public void parseRefNameParts() {
+    assertRefPart(1, "01/1");
+    assertRefPart(1, "01/1-drafts");
+    assertRefPart(1, "01/1-drafts/2");
+
+    assertNotRefPart(null);
+    assertNotRefPart("");
+
+    // This method assumes that the common prefix "refs/users/" will be removed.
+    assertNotRefPart("refs/users/01/1");
+
+    // Invalid characters.
+    assertNotRefPart("01a/1");
+    assertNotRefPart("01/a1");
+
+    // Mismatched shard.
+    assertNotRefPart("01/23");
+
+    // Shard too short.
+    assertNotRefPart("1/1");
+  }
+
+  private static void assertRefPart(int accountId, String refName) {
+    assertEquals(new Account.Id(accountId), Account.Id.fromRefPart(refName));
+  }
+
+  private static void assertNotRefPart(String refName) {
+    assertNull(Account.Id.fromRefPart(refName));
+  }
+}

diff --git a/gerrit-reviewdb/src/test/java/com/google/gerrit/reviewdb/client/PatchSetTest.java b/gerrit-reviewdb/src/test/java/com/google/gerrit/reviewdb/client/PatchSetTest.java
new file mode 100644
index 0000000..525fb18
--- /dev/null
+++ b/gerrit-reviewdb/src/test/java/com/google/gerrit/reviewdb/client/PatchSetTest.java

@@ -0,0 +1,69 @@
+// 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.reviewdb.client;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class PatchSetTest {
+  @Test
+  public void parseRefNames() {
+    assertRef(1, 1, "refs/changes/01/1/1");
+    assertRef(1234, 56, "refs/changes/34/1234/56");
+
+    // Not even close.
+    assertNotRef(null);
+    assertNotRef("");
+    assertNotRef("01/1/1");
+    assertNotRef("HEAD");
+    assertNotRef("refs/tags/v1");
+
+    // Invalid characters.
+    assertNotRef("refs/changes/0x/1/1");
+    assertNotRef("refs/changes/01/x/1");
+    assertNotRef("refs/changes/01/1/x");
+
+    // Truncations.
+    assertNotRef("refs/changes/");
+    assertNotRef("refs/changes/1");
+    assertNotRef("refs/changes/01");
+    assertNotRef("refs/changes/01/");
+    assertNotRef("refs/changes/01/1/");
+    assertNotRef("refs/changes/01/1/1/");
+    assertNotRef("refs/changes/01//1/1");
+
+    // Leading zeroes.
+    assertNotRef("refs/changes/01/01/1");
+    assertNotRef("refs/changes/01/1/01");
+
+    // Mismatched last 2 digits.
+    assertNotRef("refs/changes/35/1234/56");
+  }
+
+  private static void assertRef(int changeId, int psId, String refName) {
+    assertTrue(PatchSet.isRef(refName));
+    assertEquals(new PatchSet.Id(new Change.Id(changeId), psId),
+        PatchSet.Id.fromRef(refName));
+  }
+
+  private static void assertNotRef(String refName) {
+    assertFalse(PatchSet.isRef(refName));
+    assertNull(PatchSet.Id.fromRef(refName));
+  }
+}

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/ChangeUtil.java b/gerrit-server/src/main/java/com/google/gerrit/server/ChangeUtil.java
index 80213f6..2ed37cb 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/ChangeUtil.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/ChangeUtil.java

@@ -508,8 +508,8 @@
     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));
 

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/PatchLineCommentsUtil.java b/gerrit-server/src/main/java/com/google/gerrit/server/PatchLineCommentsUtil.java
index f917613..d12d3cc 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/PatchLineCommentsUtil.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/PatchLineCommentsUtil.java

@@ -12,25 +12,46 @@
 // 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.PatchLineComment.Status;
+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.gwtorm.server.ResultSet;
 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 +61,208 @@
  */
 @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 : publishedByChange(db, notes)) {
+      if (key.equals(c.getKey())) {
+        return Optional.of(c);
+      }
+    }
+    for (PatchLineComment c : draftByChange(db, notes)) {
+      if (key.equals(c.getKey())) {
+        return Optional.of(c);
+      }
+    }
+    return Optional.absent();
+  }
+
+  public List<PatchLineComment> publishedByChange(ReviewDb db,
+      ChangeNotes notes) throws OrmException {
+    if (!migration.readComments()) {
+      return byCommentStatus(db.patchComments().byChange(notes.getChangeId()),
+          Status.PUBLISHED);
+    }
+
+    notes.load();
+    List<PatchLineComment> comments = Lists.newArrayList();
+    comments.addAll(notes.getBaseComments().values());
+    comments.addAll(notes.getPatchSetComments().values());
+    return comments;
+  }
+
+  public List<PatchLineComment> draftByChange(ReviewDb db,
+      ChangeNotes notes) throws OrmException {
+    if (!migration.readComments()) {
+      return byCommentStatus(db.patchComments().byChange(notes.getChangeId()),
+          Status.DRAFT);
+    }
+
+    List<PatchLineComment> comments = Lists.newArrayList();
+    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;
+  }
+
+  private static List<PatchLineComment> byCommentStatus(
+      ResultSet<PatchLineComment> comments,
+      final PatchLineComment.Status status) {
+    return Lists.newArrayList(
+      Iterables.filter(comments, new Predicate<PatchLineComment>() {
+        @Override
+        public boolean apply(PatchLineComment input) {
+          return (input.getStatus() == status);
+        }
+      })
+    );
+  }
+
+  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.
-    addCommentsInFile(commentsOnFile, notes.getBaseComments().values(), file);
-    addCommentsInFile(commentsOnFile, notes.getPatchSetComments().values(),
+    addCommentsOnFile(comments, notes.getBaseComments().values(), file);
+    addCommentsOnFile(comments, notes.getPatchSetComments().values(),
         file);
-
-    Collections.sort(commentsOnFile, ChangeNotes.PatchLineCommentComparator);
-    return commentsOnFile;
+    Collections.sort(comments, ChangeNotes.PatchLineCommentComparator);
+    return comments;
   }
 
   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>();
-    commentsOnPs.addAll(notes.getPatchSetComments().get(psId));
-    commentsOnPs.addAll(notes.getBaseComments().get(psId));
-    return commentsOnPs;
+    List<PatchLineComment> comments = new ArrayList<PatchLineComment>();
+    comments.addAll(notes.getPatchSetComments().get(psId));
+    comments.addAll(notes.getBaseComments().get(psId));
+    return comments;
   }
 
-  // TODO(yyonas): Delete drafts if they already existed.
-  public void addPublishedComments(ReviewDb db, ChangeUpdate update,
+  public List<PatchLineComment> draftByPatchSetAuthor(ReviewDb db,
+      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 +270,23 @@
     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 +298,49 @@
     }
     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);
+      }
+    });
+  }
 }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/ChangeJson.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/ChangeJson.java
index 586c294..fb80984 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/ChangeJson.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/ChangeJson.java

@@ -77,6 +77,7 @@
 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 @@
   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 @@
       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 @@
     this.revisions = revisions;
     this.webLinks = webLinks;
     this.cmUtil = cmUtil;
+    this.plcUtil = plcUtil;
     options = EnumSet.noneOf(ListChangesOption.class);
   }
 
@@ -821,9 +825,8 @@
         && userProvider.get().isIdentifiedUser()) {
       IdentifiedUser user = (IdentifiedUser)userProvider.get();
       out.hasDraftComments =
-          db.get().patchComments()
-              .draftByPatchSetAuthor(in.getId(), user.getAccountId())
-              .iterator().hasNext()
+          plcUtil.draftByPatchSetAuthor(db.get(), in.getId(),
+              user.getAccountId(), ctl.getNotes()).iterator().hasNext()
           ? true
           : null;
     }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/CreateDraft.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/CreateDraft.java
index 1d2fa406..b025e65 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/CreateDraft.java
+++ b/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.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 @@
         ? 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));
   }
 }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/DeleteDraft.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/DeleteDraft.java
index 46ae834..f7fb300 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/DeleteDraft.java
+++ b/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 @@
   }
 
   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 {
-    db.get().patchComments().delete(Collections.singleton(rsrc.getComment()));
+      throws OrmException, IOException {
+    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();
   }
 }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/Drafts.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/Drafts.java
index 322faea..b0ed7d0 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/Drafts.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/Drafts.java

@@ -23,6 +23,7 @@
 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 @@
   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 @@
       throws ResourceNotFoundException, OrmException, AuthException {
     checkIdentifiedUser();
     String uuid = id.get();
-    for (PatchLineComment c : dbProvider.get().patchComments()
-        .draftByPatchSetAuthor(
-            rev.getPatchSet().getId(),
-            rev.getAccountId())) {
+    for (PatchLineComment c : plcUtil.draftByPatchSetAuthor(dbProvider.get(),
+        rev.getPatchSet().getId(), rev.getAccountId(), rev.getNotes())) {
       if (uuid.equals(c.getKey().get())) {
         return new DraftResource(rev, c);
       }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/ListComments.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/ListComments.java
index f4d7b49..146ded8 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/ListComments.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/ListComments.java

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

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/ListDrafts.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/ListDrafts.java
index bd3aa04..1a26898 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/ListDrafts.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/ListDrafts.java

@@ -22,6 +22,7 @@
 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 @@
 @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()
-        .draftByPatchSetAuthor(
-            rsrc.getPatchSet().getId(),
-            rsrc.getAccountId());
+    return plcUtil.draftByPatchSetAuthor(db.get(), rsrc.getPatchSet().getId(),
+        rsrc.getAccountId(), rsrc.getNotes());
   }
 
   protected boolean includeAuthorInfo() {

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/PostReview.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/PostReview.java
index 9a2a81e..bf8474f 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/PostReview.java
+++ b/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.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.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.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 @@
     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 @@
         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 @@
         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.addPublishedComments(db.get(), update, ups);
+    plcUtil.deleteComments(db.get(), update, del);
+    plcUtil.upsertComments(db.get(), update, ups);
     comments.addAll(ups);
     return !del.isEmpty() || !ups.isEmpty();
   }
@@ -412,9 +402,8 @@
   private Map<String, PatchLineComment> scanDraftComments(
       RevisionResource rsrc) throws OrmException {
     Map<String, PatchLineComment> drafts = Maps.newHashMap();
-    for (PatchLineComment c : db.get().patchComments().draftByPatchSetAuthor(
-          rsrc.getPatchSet().getId(),
-          rsrc.getAccountId())) {
+    for (PatchLineComment c : plcUtil.draftByPatchSetAuthor(db.get(),
+        rsrc.getPatchSet().getId(), rsrc.getAccountId(), rsrc.getNotes())) {
       drafts.put(c.getKey().get(), c);
     }
     return drafts;

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/PutDraft.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/PutDraft.java
index c1fb304..a3b0614 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/PutDraft.java
+++ b/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.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 @@
 
   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 @@
         && !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 @@
           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));
   }
 

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/MetaDataUpdate.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/MetaDataUpdate.java
index b48028e..b65cc85 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/MetaDataUpdate.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/MetaDataUpdate.java

@@ -14,6 +14,7 @@
 
 package com.google.gerrit.server.git;
 
+import com.google.gerrit.common.Nullable;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.IdentifiedUser;
@@ -21,8 +22,10 @@
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.assistedinject.Assisted;
+import com.google.inject.assistedinject.AssistedInject;
 
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
+import org.eclipse.jgit.lib.BatchRefUpdate;
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.RefUpdate;
@@ -59,7 +62,24 @@
 
     public MetaDataUpdate create(Project.NameKey name, IdentifiedUser user)
         throws RepositoryNotFoundException, IOException {
-      MetaDataUpdate md = factory.create(name, mgr.openRepository(name));
+      return create(name, user, null);
+    }
+
+  /**
+   * Create an update using an existing batch ref update.
+   * <p>
+   * This allows batching together updates to multiple metadata refs. For making
+   * multiple commits to a single metadata ref, see
+   * {@link VersionedMetaData#openUpdate(MetaDataUpdate)}.
+   *
+   * @param name project name.
+   * @param user user for the update.
+   * @param batch batch update to use; the caller is responsible for committing
+   *     the update.
+   */
+    public MetaDataUpdate create(Project.NameKey name, IdentifiedUser user,
+        BatchRefUpdate batch) throws RepositoryNotFoundException, IOException {
+      MetaDataUpdate md = factory.create(name, mgr.openRepository(name), batch);
       md.getCommitBuilder().setAuthor(createPersonIdent(user));
       md.getCommitBuilder().setCommitter(serverIdent);
       return md;
@@ -86,7 +106,13 @@
 
     public MetaDataUpdate create(Project.NameKey name)
         throws RepositoryNotFoundException, IOException {
-      MetaDataUpdate md = factory.create(name, mgr.openRepository(name));
+      return create(name, null);
+    }
+
+    /** @see User#create(Project.NameKey, IdentifiedUser, BatchRefUpdate) */
+    public MetaDataUpdate create(Project.NameKey name, BatchRefUpdate batch)
+        throws RepositoryNotFoundException, IOException {
+      MetaDataUpdate md = factory.create(name, mgr.openRepository(name), batch);
       md.getCommitBuilder().setAuthor(serverIdent);
       md.getCommitBuilder().setCommitter(serverIdent);
       return md;
@@ -95,24 +121,32 @@
 
   interface InternalFactory {
     MetaDataUpdate create(@Assisted Project.NameKey projectName,
-        @Assisted Repository db);
+        @Assisted Repository db, @Assisted @Nullable BatchRefUpdate batch);
   }
 
   private final GitReferenceUpdated gitRefUpdated;
   private final Project.NameKey projectName;
   private final Repository db;
+  private final BatchRefUpdate batch;
   private final CommitBuilder commit;
   private boolean allowEmpty;
 
-  @Inject
+  @AssistedInject
   public MetaDataUpdate(GitReferenceUpdated gitRefUpdated,
-      @Assisted Project.NameKey projectName, @Assisted Repository db) {
+      @Assisted Project.NameKey projectName, @Assisted Repository db,
+      @Assisted @Nullable BatchRefUpdate batch) {
     this.gitRefUpdated = gitRefUpdated;
     this.projectName = projectName;
     this.db = db;
+    this.batch = batch;
     this.commit = new CommitBuilder();
   }
 
+  public MetaDataUpdate(GitReferenceUpdated gitRefUpdated,
+      Project.NameKey projectName, Repository db) {
+    this(gitRefUpdated, projectName, db, null);
+  }
+
   /** Set the commit message used when committing the update. */
   public void setMessage(String message) {
     getCommitBuilder().setMessage(message);
@@ -128,6 +162,11 @@
     this.allowEmpty = allowEmpty;
   }
 
+  /** @return batch in which to run the update, or {@code null} for no batch. */
+  BatchRefUpdate getBatch() {
+    return batch;
+  }
+
   /** Close the cached Repository handle. */
   public void close() {
     getRepository().close();

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java
index b12750d..0a91f2e 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java

@@ -2131,8 +2131,11 @@
           allRefs.size() / estRefsPerChange,
           estRefsPerChange);
       for (Ref ref : allRefs.values()) {
-        if (ref.getObjectId() != null && PatchSet.isRef(ref.getName())) {
-          refsByChange.put(Change.Id.fromRef(ref.getName()), ref);
+        if (ref.getObjectId() != null) {
+          PatchSet.Id psId = PatchSet.Id.fromRef(ref.getName());
+          if (psId != null) {
+            refsByChange.put(psId.getParentKey(), ref);
+          }
         }
       }
     }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/VersionedMetaData.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/VersionedMetaData.java
index 4c5ebc6..a58d9b6 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/VersionedMetaData.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/VersionedMetaData.java

@@ -26,6 +26,7 @@
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.BatchRefUpdate;
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Constants;
@@ -40,6 +41,7 @@
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevTree;
 import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.transport.ReceiveCommand;
 import org.eclipse.jgit.treewalk.TreeWalk;
 import org.eclipse.jgit.util.RawParseUtils;
 
@@ -181,6 +183,21 @@
     void close();
   }
 
+  /**
+   * Open a batch of updates to the same metadata ref.
+   * <p>
+   * This allows making multiple commits to a single metadata ref, at the end of
+   * which is a single ref update. For batching together updates to multiple
+   * refs (each consisting of one or more commits against their respective
+   * refs), create the {@link MetaDataUpdate} with a {@link BatchRefUpdate}.
+   * <p>
+   * A ref update produced by this {@link BatchMetaDataUpdate} is only committed
+   * if there is no associated {@link BatchRefUpdate}. As a result, the
+   * configured ref updated event is not fired if there is an associated batch.
+   *
+   * @param update helper info about the update.
+   * @throws IOException if the update failed.
+   */
   public BatchMetaDataUpdate openUpdate(final MetaDataUpdate update) throws IOException {
     final Repository db = update.getRepository();
 
@@ -302,6 +319,15 @@
 
       private RevCommit updateRef(AnyObjectId oldId, AnyObjectId newId,
           String refName) throws IOException {
+        BatchRefUpdate bru = update.getBatch();
+        if (bru != null) {
+          bru.addCommand(new ReceiveCommand(
+              oldId.toObjectId(), newId.toObjectId(), refName));
+          inserter.flush();
+          revision = rw.parseCommit(newId);
+          return revision;
+        }
+
         RefUpdate ru = db.updateRef(refName);
         ru.setExpectedOldObjectId(oldId);
         ru.setNewObjectId(src);

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/VisibleRefFilter.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/VisibleRefFilter.java
index 3b1a8fb..30db2b9 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/VisibleRefFilter.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/VisibleRefFilter.java

@@ -82,12 +82,13 @@
     final List<Ref> deferredTags = new ArrayList<>();
 
     for (Ref ref : refs.values()) {
+      PatchSet.Id psId;
       if (ref.getName().startsWith(RefNames.REFS_CACHE_AUTOMERGE)) {
         continue;
-      } else if (PatchSet.isRef(ref.getName())) {
+      } else if ((psId = PatchSet.Id.fromRef(ref.getName())) != null) {
         // Reference to a patch set is visible if the change is visible.
         //
-        if (showChanges && visibleChanges.contains(Change.Id.fromRef(ref.getName()))) {
+        if (showChanges && visibleChanges.contains(psId.getParentKey())) {
           result.put(ref.getName(), ref);
         }
 

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/index/ChangeField.java b/gerrit-server/src/main/java/com/google/gerrit/server/index/ChangeField.java
index 41dfba5..68e7857 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/index/ChangeField.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/index/ChangeField.java

@@ -408,7 +408,7 @@
         public Iterable<String> get(ChangeData input, FillArgs args)
             throws OrmException {
           Set<String> r = Sets.newHashSet();
-          for (PatchLineComment c : input.comments()) {
+          for (PatchLineComment c : input.publishedComments()) {
             r.add(c.getMessage());
           }
           for (ChangeMessage m : input.messages()) {

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/mail/CommentSender.java b/gerrit-server/src/main/java/com/google/gerrit/server/mail/CommentSender.java
index 2beb49f..5f2ffcb 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/mail/CommentSender.java
+++ b/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.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 @@
 
   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 @@
 
   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(
-            new PatchLineComment.Key(
-                child.getKey().getParentKey(),
-                child.getParentUuid()));
+        parent = plcUtil.get(args.db.get(), changeData.notes(), key);
       } catch (OrmException e) {
-        parent = null;
+        log.warn("Could not find the parent of this comment: "
+            + child.toString());
+        parent = Optional.absent();
       }
-      if (parent != null) {
-        String msg = parent.getMessage().trim();
+      if (parent.isPresent()) {
+        String msg = parent.get().getMessage().trim();
         if (msg.length() > 75) {
           msg = msg.substring(0, 75);
         }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/AbstractChangeUpdate.java b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/AbstractChangeUpdate.java
index e1641b8..f114af0 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/AbstractChangeUpdate.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/AbstractChangeUpdate.java

@@ -29,6 +29,7 @@
 import com.google.gerrit.server.project.ChangeControl;
 
 import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.lib.BatchRefUpdate;
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.PersonIdent;
@@ -105,10 +106,15 @@
   }
 
   public BatchMetaDataUpdate openUpdate() throws IOException {
+    return openUpdateInBatch(null);
+  }
+
+  public BatchMetaDataUpdate openUpdateInBatch(BatchRefUpdate bru)
+      throws IOException {
     if (migration.write()) {
       load();
       MetaDataUpdate md =
-          updateFactory.create(getProjectName(), getUser());
+          updateFactory.create(getProjectName(), getUser(), bru);
       md.setAllowEmpty(true);
       return super.openUpdate(md);
     }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeDraftUpdate.java b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeDraftUpdate.java
index 7510412..ca32c14 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeDraftUpdate.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeDraftUpdate.java

@@ -105,9 +105,11 @@
     verifyComment(c);
     checkArgument(c.getStatus() == Status.DRAFT,
         "Cannot insert a published comment into a ChangeDraftUpdate");
-    checkArgument(!changeNotes.containsComment(c),
-        "A comment already exists with the same key,"
-        + " so the following comment cannot be inserted: %s", c);
+    if (migration.readComments()) {
+      checkArgument(!changeNotes.containsComment(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 @@
     verifyComment(c);
     checkArgument(c.getStatus() == Status.DRAFT,
         "Cannot update a published comment into a ChangeDraftUpdate");
-    checkArgument(draftNotes.containsComment(c),
-        "Cannot update this comment because it didn't exist previously");
+    // Here, we check to see if this comment existed previously as a draft.
+    // 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"
-        + " because it didn't previously exist as a draft");
-    deleteComments.add(c);
+    // See the comment above about potential race condition.
+    if (migration.readComments()) {
+      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 @@
     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 @@
     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 @@
     updateNoteMap(revisionSideChanged, noteMap, newPsDrafts,
         psRevId);
 
-    removedAllComments.set(baseDrafts.isEmpty() && psDrafts.isEmpty());
+    removedAllComments.set(
+        baseDrafts.isEmpty() && psDrafts.isEmpty() && !draftsEmpty);
 
     return noteMap.writeTree(inserter);
   }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeUpdate.java b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeUpdate.java
index 24d4b46..770315a 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeUpdate.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeUpdate.java

@@ -239,9 +239,11 @@
     if (notes == null) {
       notes = getChangeNotes().load();
     }
-    checkArgument(!notes.containsComment(c),
-        "A comment already exists with the same key as the following comment,"
-        + " so we cannot insert this comment: %s", c);
+    if (migration.readComments()) {
+      checkArgument(!notes.containsComment(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 @@
     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 @@
     if (notes == null) {
       notes = getChangeNotes().load();
     }
-    checkArgument(!notes.containsCommentPublished(c),
-        "Cannot update a comment that has already been published and saved");
+    // See comment above in upsertPublishedComment() about potential risk with
+    // 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 @@
     draftUpdate.deleteCommentIfPresent(c);
   }
 
-
   private void createDraftUpdateIfNull(PatchLineComment c) throws OrmException {
     if (draftUpdate == null) {
       draftUpdate = draftUpdateFactory.create(ctl, when);

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/CommentsInNotesUtil.java b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/CommentsInNotesUtil.java
index 99f9542..c2e5dfc 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/CommentsInNotesUtil.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/CommentsInNotesUtil.java

@@ -239,6 +239,7 @@
 
     if (note[ptr.value] == '\n') {
       range.setEndLine(startLine);
+      ptr.value += 1;
       return range;
     } else if (note[ptr.value] == ':') {
       range.setStartLine(startLine);

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/NotesMigration.java b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/NotesMigration.java
index 36f685d..679e272 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/notedb/NotesMigration.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/notedb/NotesMigration.java

@@ -36,14 +36,14 @@
     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 @@
         cfg.getBoolean("notedb", "patchSetApprovals", "read", false);
     readChangeMessages =
         cfg.getBoolean("notedb", "changeMessages", "read", false);
-    readPublishedComments =
-        cfg.getBoolean("notedb", "publishedComments", "read", false);
+    readComments =
+        cfg.getBoolean("notedb", "comments", "read", false);
   }
 
   public boolean write() {
@@ -68,7 +68,7 @@
     return readChangeMessages;
   }
 
-  public boolean readPublishedComments() {
-    return readPublishedComments;
+  public boolean readComments() {
+    return readComments;
   }
 }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchScriptFactory.java b/gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchScriptFactory.java
index b4337cf..decae6d 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchScriptFactory.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/patch/PatchScriptFactory.java

@@ -338,7 +338,8 @@
   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);
       }

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/BasicChangeRewrites.java b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/BasicChangeRewrites.java
index 8ce6fa3..37d96ea 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/BasicChangeRewrites.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/BasicChangeRewrites.java

@@ -30,7 +30,8 @@
           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>(

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeData.java b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeData.java
index ed64015..0310824 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeData.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeData.java

@@ -35,6 +35,7 @@
 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 @@
    */
   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 @@
   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;
@@ -179,7 +181,7 @@
   private ListMultimap<PatchSet.Id, PatchSetApproval> allApprovals;
   private List<PatchSetApproval> currentApprovals;
   private Map<Integer, List<String>> files = new HashMap<>();
-  private Collection<PatchLineComment> comments;
+  private Collection<PatchLineComment> publishedComments;
   private CurrentUser visibleTo;
   private ChangeControl changeControl;
   private List<ChangeMessage> messages;
@@ -194,6 +196,7 @@
       ChangeNotes.Factory notesFactory,
       ApprovalsUtil approvalsUtil,
       ChangeMessagesUtil cmUtil,
+      PatchLineCommentsUtil plcUtil,
       PatchListCache patchListCache,
       NotesMigration notesMigration,
       @Assisted ReviewDb db,
@@ -205,6 +208,7 @@
     this.notesFactory = notesFactory;
     this.approvalsUtil = approvalsUtil;
     this.cmUtil = cmUtil;
+    this.plcUtil = plcUtil;
     this.patchListCache = patchListCache;
     this.notesMigration = notesMigration;
     legacyId = id;
@@ -218,6 +222,7 @@
       ChangeNotes.Factory notesFactory,
       ApprovalsUtil approvalsUtil,
       ChangeMessagesUtil cmUtil,
+      PatchLineCommentsUtil plcUtil,
       PatchListCache patchListCache,
       NotesMigration notesMigration,
       @Assisted ReviewDb db,
@@ -229,6 +234,7 @@
     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 @@
       ChangeNotes.Factory notesFactory,
       ApprovalsUtil approvalsUtil,
       ChangeMessagesUtil cmUtil,
+      PatchLineCommentsUtil plcUtil,
       PatchListCache patchListCache,
       NotesMigration notesMigration,
       @Assisted ReviewDb db,
@@ -254,6 +261,7 @@
     this.notesFactory = notesFactory;
     this.approvalsUtil = approvalsUtil;
     this.cmUtil = cmUtil;
+    this.plcUtil = plcUtil;
     this.patchListCache = patchListCache;
     this.notesMigration = notesMigration;
     legacyId = c.getChange().getId();
@@ -519,12 +527,12 @@
     return approvalsUtil.getReviewers(notes(), approvals().values());
   }
 
-  public Collection<PatchLineComment> comments()
+  public Collection<PatchLineComment> publishedComments()
       throws OrmException {
-    if (comments == null) {
-      comments = db.patchComments().byChange(legacyId).toList();
+    if (publishedComments == null) {
+      publishedComments = plcUtil.publishedByChange(db, notes());
     }
-    return comments;
+    return publishedComments;
   }
 
   public List<ChangeMessage> messages()

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java
index ac7b9ae..fabe61c 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java

@@ -25,6 +25,7 @@
 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 @@
     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 @@
         CapabilityControl.Factory capabilityControlFactory,
         ChangeControl.GenericFactory changeControlGenericFactory,
         ChangeData.Factory changeDataFactory,
+        PatchLineCommentsUtil plcUtil,
         AccountResolver accountResolver,
         GroupBackend groupBackend,
         AllProjectsName allProjectsName,
@@ -187,6 +190,7 @@
       this.capabilityControlFactory = capabilityControlFactory;
       this.changeControlGenericFactory = changeControlGenericFactory;
       this.changeDataFactory = changeDataFactory;
+      this.plcUtil = plcUtil;
       this.accountResolver = accountResolver;
       this.groupBackend = groupBackend;
       this.allProjectsName = allProjectsName;

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/HasDraftByPredicate.java b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/HasDraftByPredicate.java
index 53d2bbd..ebb7389 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/HasDraftByPredicate.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/HasDraftByPredicate.java

@@ -33,7 +33,8 @@
   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 @@
 
   @Override
   public boolean match(final ChangeData object) throws OrmException {
-    for (PatchLineComment c : object.comments()) {
-      if (c.getStatus() == PatchLineComment.Status.DRAFT
-          && c.getAuthor().equals(accountId)) {
-        return true;
-      }
-    }
-    return false;
+    return !args.plcUtil
+        .draftByChangeAuthor(args.db.get(), object.notes(), accountId)
+        .isEmpty();
   }
 
   @Override
   public ResultSet<ChangeData> read() throws OrmException {
     Set<Change.Id> ids = new HashSet<>();
-    for (PatchLineComment sc : args.db.get().patchComments()
-        .draftByAuthor(accountId)) {
+    for (PatchLineComment sc :
+        args.plcUtil.draftByAuthor(args.db.get(), accountId)) {
       ids.add(sc.getKey().getParentKey().getParentKey().getParentKey());
     }
 

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/QueryProcessor.java b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/QueryProcessor.java
index 8889f53..f6a6108 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/query/change/QueryProcessor.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/query/change/QueryProcessor.java

@@ -366,7 +366,7 @@
             eventFactory.addComments(c, d.messages());
             if (includePatchSets) {
               for (PatchSetAttribute attribute : c.patchSets) {
-                eventFactory.addPatchSetComments(attribute,  d.comments());
+                eventFactory.addPatchSetComments(attribute,  d.publishedComments());
               }
             }
           }

diff --git a/gerrit-server/src/test/java/com/google/gerrit/server/change/CommentsTest.java b/gerrit-server/src/test/java/com/google/gerrit/server/change/CommentsTest.java
index da687be..a8880a1 100644
--- a/gerrit-server/src/test/java/com/google/gerrit/server/change/CommentsTest.java
+++ b/gerrit-server/src/test/java/com/google/gerrit/server/change/CommentsTest.java

@@ -21,6 +21,7 @@
 import static org.easymock.EasyMock.replay;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import com.google.common.base.Objects;
@@ -43,6 +44,7 @@
 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 +62,6 @@
 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 +75,8 @@
 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 +107,7 @@
   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 +121,23 @@
   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 +150,23 @@
     @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 +186,16 @@
         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 +211,10 @@
     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();
 
@@ -208,7 +224,7 @@
     PatchSet.Id psId2 = new PatchSet.Id(change.getId(), 2);
     PatchSet ps2 = new PatchSet(psId2);
 
-    long timeBase = TimeUtil.nowMs();
+    long timeBase = TimeUtil.roundToSecond(TimeUtil.nowTs()).getTime();
     plc1 = newPatchLineComment(psId1, "Comment1", null,
         "FileOne.txt", Side.REVISION, 3, ownerId, timeBase,
         "First Comment", new CommentRange(1, 2, 3, 4));
@@ -221,32 +237,56 @@
         "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();
+    expect(plca.byChange(change.getId()))
+        .andAnswer(results(plc1, plc2, plc3, 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 +326,37 @@
     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)));
+  }
+
+  @Test
+  public void testPatchLineCommentsUtilByCommentStatus() throws OrmException {
+    List<PatchLineComment> publishedActual = plcUtil.publishedByChange(
+        injector.getInstance(ReviewDb.class), revRes2.getNotes());
+    List<PatchLineComment> draftActual = plcUtil.draftByChange(
+        injector.getInstance(ReviewDb.class), revRes2.getNotes());
+    List<PatchLineComment> publishedExpected =
+        Lists.newArrayList(plc1, plc2, plc3);
+    List<PatchLineComment> draftExpected =
+        Lists.newArrayList(plc4, plc5);
+    assertEquals(publishedExpected.size(), publishedActual.size());
+    assertEquals(draftExpected.size(), draftActual.size());
+    for (PatchLineComment c : draftExpected) {
+      assertTrue(draftActual.contains(c));
+    }
+    for (PatchLineComment c : publishedExpected) {
+      assertTrue(publishedActual.contains(c));
+    }
+  }
+
   private static IAnswer<ResultSet<PatchLineComment>> results(
       final PatchLineComment... comments) {
     return new IAnswer<ResultSet<PatchLineComment>>() {
@@ -305,7 +376,7 @@
         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 +401,42 @@
       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);
-    assertEquals(plc.getAuthor(), ci.author._id);
+    if (isPublished) {
+      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 +447,8 @@
 
   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 +456,15 @@
     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);
+  }
 }

diff --git a/gerrit-server/src/test/java/com/google/gerrit/server/index/FakeQueryBuilder.java b/gerrit-server/src/test/java/com/google/gerrit/server/index/FakeQueryBuilder.java
index 50e5764..7090f0d 100644
--- a/gerrit-server/src/test/java/com/google/gerrit/server/index/FakeQueryBuilder.java
+++ b/gerrit-server/src/test/java/com/google/gerrit/server/index/FakeQueryBuilder.java

@@ -26,8 +26,8 @@
         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, null, null, indexes, null,
+          null, null, null),
         null);
   }
 

diff --git a/gerrit-server/src/test/java/com/google/gerrit/server/notedb/ChangeNotesTest.java b/gerrit-server/src/test/java/com/google/gerrit/server/notedb/ChangeNotesTest.java
index 6db2557..72e3838 100644
--- a/gerrit-server/src/test/java/com/google/gerrit/server/notedb/ChangeNotesTest.java
+++ b/gerrit-server/src/test/java/com/google/gerrit/server/notedb/ChangeNotesTest.java

@@ -62,13 +62,12 @@
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.git.VersionedMetaData.BatchMetaDataUpdate;
 import com.google.gerrit.server.group.SystemGroupBackend;
-import com.google.gerrit.server.notedb.CommentsInNotesUtil;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.util.TimeUtil;
-import com.google.gerrit.testutil.TestChanges;
 import com.google.gerrit.testutil.FakeAccountCache;
 import com.google.gerrit.testutil.FakeRealm;
 import com.google.gerrit.testutil.InMemoryRepositoryManager;
+import com.google.gerrit.testutil.TestChanges;
 import com.google.gwtorm.client.KeyUtil;
 import com.google.gwtorm.server.OrmException;
 import com.google.gwtorm.server.StandardKeyEncoder;
@@ -77,13 +76,16 @@
 import com.google.inject.util.Providers;
 
 import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
+import org.eclipse.jgit.lib.BatchRefUpdate;
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.NullProgressMonitor;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.notes.Note;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.transport.ReceiveCommand;
 import org.joda.time.DateTime;
 import org.joda.time.DateTimeUtils;
 import org.joda.time.DateTimeUtils.MillisProvider;
@@ -695,6 +697,58 @@
   }
 
   @Test
+  public void multipleUpdatesAcrossRefs() throws Exception {
+    Change c1 = newChange();
+    ChangeUpdate update1 = newUpdate(c1, changeOwner);
+    update1.putApproval("Verified", (short) 1);
+
+    Change c2 = newChange();
+    ChangeUpdate update2 = newUpdate(c2, otherUser);
+    update2.putApproval("Code-Review", (short) 2);
+
+    BatchMetaDataUpdate batch1 = null;
+    BatchMetaDataUpdate batch2 = null;
+
+    BatchRefUpdate bru = repo.getRefDatabase().newBatchUpdate();
+    try {
+      batch1 = update1.openUpdateInBatch(bru);
+      batch1.write(update1, new CommitBuilder());
+      batch1.commit();
+      assertNull(repo.getRef(update1.getRefName()));
+
+      batch2 = update2.openUpdateInBatch(bru);
+      batch2.write(update2, new CommitBuilder());
+      batch2.commit();
+      assertNull(repo.getRef(update2.getRefName()));
+    } finally {
+      if (batch1 != null) {
+        batch1.close();
+      }
+      if (batch2 != null) {
+        batch2.close();
+      }
+    }
+
+    List<ReceiveCommand> cmds = bru.getCommands();
+    assertEquals(2, cmds.size());
+    assertEquals(update1.getRefName(), cmds.get(0).getRefName());
+    assertEquals(update2.getRefName(), cmds.get(1).getRefName());
+
+    RevWalk rw = new RevWalk(repo);
+    try {
+      bru.execute(rw, NullProgressMonitor.INSTANCE);
+    } finally {
+      rw.release();
+    }
+
+    assertEquals(ReceiveCommand.Result.OK, cmds.get(0).getResult());
+    assertEquals(ReceiveCommand.Result.OK, cmds.get(1).getResult());
+
+    assertNotNull(repo.getRef(update1.getRefName()));
+    assertNotNull(repo.getRef(update2.getRefName()));
+  }
+
+  @Test
   public void changeMessageOnePatchSet() throws Exception {
     Change c = newChange();
     ChangeUpdate update = newUpdate(c, changeOwner);
@@ -895,7 +949,9 @@
   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 +962,7 @@
     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 +971,7 @@
     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 +980,7 @@
     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 +1004,14 @@
         + "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 +1020,7 @@
         + "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 +1031,8 @@
   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 +1041,7 @@
     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 +1050,7 @@
     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 +1074,14 @@
         + "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 +1094,8 @@
       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 +1103,7 @@
     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 +1112,7 @@
 
     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 +1136,8 @@
   @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 +1147,7 @@
     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 +1155,7 @@
 
     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);
@@ -1370,6 +1429,34 @@
     assertTrue(notes.getDraftPsComments(otherUserId).values().isEmpty());
   }
 
+  @Test
+  public void patchLineCommentNoRange() throws Exception {
+    Change c = newChange();
+    ChangeUpdate update = newUpdate(c, otherUser);
+    String uuid = "uuid";
+    String messageForBase = "comment for base";
+    Timestamp now = TimeUtil.nowTs();
+    PatchSet.Id psId = c.currentPatchSetId();
+
+    PatchLineComment commentForBase =
+        newPublishedPatchLineComment(psId, "filename", uuid,
+        null, 1, otherUser, null, now, messageForBase,
+        (short) 0, "abcd1234abcd1234abcd1234abcd1234abcd1234");
+    update.setPatchSetId(psId);
+    update.upsertComment(commentForBase);
+    update.commit();
+
+    ChangeNotes notes = newNotes(c);
+    Multimap<PatchSet.Id, PatchLineComment> commentsForBase =
+        notes.getBaseComments();
+    Multimap<PatchSet.Id, PatchLineComment> commentsForPs =
+        notes.getPatchSetComments();
+
+    assertTrue(commentsForPs.isEmpty());
+    assertEquals(commentForBase,
+        Iterables.getOnlyElement(commentsForBase.get(psId)));
+  }
+
   private Change newChange() {
     return TestChanges.newChange(project, changeOwner);
   }

diff --git a/tools/eclipse/BUCK b/tools/eclipse/BUCK
index 4e76b029..2cc66a0 100644
--- a/tools/eclipse/BUCK
+++ b/tools/eclipse/BUCK

@@ -11,6 +11,7 @@
     '//gerrit-main:main_lib',
     '//gerrit-patch-jgit:jgit_patch_tests',
     '//gerrit-plugin-gwtui:gwtui-api-lib',
+    '//gerrit-reviewdb:client_tests',
     '//gerrit-server:server',
     '//gerrit-server:server_tests',
     '//lib/asciidoctor:asciidoc_lib',