Merge "Tweak `isExpandable` of check result row"
diff --git a/Documentation/rest-api-changes.txt b/Documentation/rest-api-changes.txt
index 75d8847..2810d1e 100644
--- a/Documentation/rest-api-changes.txt
+++ b/Documentation/rest-api-changes.txt
@@ -6709,6 +6709,7 @@
 |`patch`             |required|
 The patch to be applied. Must be compatible with `git diff` output.
 For example, link:#get-patch[Get Patch] output.
+The patch must be provided as UTF-8 text, either directly or base64-encoded.
 |=================================
 
 [[applypatchpatchset-input]]
diff --git a/java/com/google/gerrit/acceptance/GerritServer.java b/java/com/google/gerrit/acceptance/GerritServer.java
index a149f29..36bc3c4 100644
--- a/java/com/google/gerrit/acceptance/GerritServer.java
+++ b/java/com/google/gerrit/acceptance/GerritServer.java
@@ -67,6 +67,7 @@
 import com.google.gerrit.server.util.ReplicaUtil;
 import com.google.gerrit.server.util.SocketUtil;
 import com.google.gerrit.server.util.SystemLog;
+import com.google.gerrit.testing.FakeAccountPatchReviewStore.FakeAccountPatchReviewStoreModule;
 import com.google.gerrit.testing.FakeEmailSender.FakeEmailSenderModule;
 import com.google.gerrit.testing.InMemoryRepositoryManager;
 import com.google.gerrit.testing.SshMode;
@@ -414,6 +415,7 @@
               }
             },
             site);
+    daemon.setAccountPatchReviewStoreModuleForTesting(new FakeAccountPatchReviewStoreModule());
     daemon.setEmailModuleForTesting(new FakeEmailSenderModule());
     daemon.setAuditEventModuleForTesting(
         MoreObjects.firstNonNull(testAuditModule, new FakeGroupAuditServiceModule()));
diff --git a/java/com/google/gerrit/acceptance/TestMetricMaker.java b/java/com/google/gerrit/acceptance/TestMetricMaker.java
index 85c5b6d..647eb9d 100644
--- a/java/com/google/gerrit/acceptance/TestMetricMaker.java
+++ b/java/com/google/gerrit/acceptance/TestMetricMaker.java
@@ -14,20 +14,26 @@
 
 package com.google.gerrit.acceptance;
 
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableList;
 import com.google.gerrit.metrics.Counter0;
+import com.google.gerrit.metrics.Counter1;
+import com.google.gerrit.metrics.Counter2;
+import com.google.gerrit.metrics.Counter3;
 import com.google.gerrit.metrics.Description;
 import com.google.gerrit.metrics.DisabledMetricMaker;
+import com.google.gerrit.metrics.Field;
 import com.google.inject.Singleton;
+import java.util.Arrays;
 import java.util.concurrent.ConcurrentHashMap;
 import org.apache.commons.lang3.mutable.MutableLong;
 
 /**
  * {@link com.google.gerrit.metrics.MetricMaker} to be bound in tests.
  *
- * <p>Records how often {@link Counter0} metrics are invoked. Metrics of other types are not
- * recorded.
+ * <p>Records how often counter metrics are invoked. Metrics of other types are not recorded.
  *
- * <p>Allows test to check how much a {@link Counter0} metrics is increased by an operation.
+ * <p>Allows test to check how much a counter metrics is increased by an operation.
  *
  * <p>Example:
  *
@@ -48,18 +54,18 @@
  */
 @Singleton
 public class TestMetricMaker extends DisabledMetricMaker {
-  private final ConcurrentHashMap<String, MutableLong> counts = new ConcurrentHashMap<>();
+  private final ConcurrentHashMap<CounterKey, MutableLong> counts = new ConcurrentHashMap<>();
 
-  public long getCount(String counter0Name) {
-    return get(counter0Name).longValue();
+  public long getCount(String counterName, Object... fieldValues) {
+    return get(CounterKey.create(counterName, fieldValues)).longValue();
   }
 
   public void reset() {
     counts.clear();
   }
 
-  private MutableLong get(String counter0Name) {
-    return counts.computeIfAbsent(counter0Name, name -> new MutableLong(0));
+  private MutableLong get(CounterKey counterKey) {
+    return counts.computeIfAbsent(counterKey, key -> new MutableLong(0));
   }
 
   @Override
@@ -67,11 +73,64 @@
     return new Counter0() {
       @Override
       public void incrementBy(long value) {
-        get(name).add(value);
+        get(CounterKey.create(name)).add(value);
       }
 
       @Override
       public void remove() {}
     };
   }
+
+  @Override
+  public <F1> Counter1<F1> newCounter(String name, Description desc, Field<F1> field1) {
+    return new Counter1<>() {
+      @Override
+      public void incrementBy(F1 field1, long value) {
+        get(CounterKey.create(name, field1)).add(value);
+      }
+
+      @Override
+      public void remove() {}
+    };
+  }
+
+  @Override
+  public <F1, F2> Counter2<F1, F2> newCounter(
+      String name, Description desc, Field<F1> field1, Field<F2> field2) {
+    return new Counter2<>() {
+      @Override
+      public void incrementBy(F1 field1, F2 field2, long value) {
+        get(CounterKey.create(name, field1, field2)).add(value);
+      }
+
+      @Override
+      public void remove() {}
+    };
+  }
+
+  @Override
+  public <F1, F2, F3> Counter3<F1, F2, F3> newCounter(
+      String name, Description desc, Field<F1> field1, Field<F2> field2, Field<F3> field3) {
+    return new Counter3<>() {
+      @Override
+      public void incrementBy(F1 field1, F2 field2, F3 field3, long value) {
+        get(CounterKey.create(name, field1, field2, field3)).add(value);
+      }
+
+      @Override
+      public void remove() {}
+    };
+  }
+
+  @AutoValue
+  abstract static class CounterKey {
+    abstract String name();
+
+    abstract ImmutableList<Object> fieldValues();
+
+    static CounterKey create(String name, Object... fieldValues) {
+      return new AutoValue_TestMetricMaker_CounterKey(
+          name, ImmutableList.copyOf(Arrays.asList(fieldValues)));
+    }
+  }
 }
diff --git a/java/com/google/gerrit/entities/RefNames.java b/java/com/google/gerrit/entities/RefNames.java
index 66ffa42..e79c530 100644
--- a/java/com/google/gerrit/entities/RefNames.java
+++ b/java/com/google/gerrit/entities/RefNames.java
@@ -195,7 +195,7 @@
     return ref.startsWith(REFS_TAGS);
   }
 
-  /** True if the provided ref is {@link REFS_EXTERNAL_IDS}. */
+  /** True if the provided ref is {@link #REFS_EXTERNAL_IDS}. */
   public static boolean isExternalIdRef(String ref) {
     return REFS_EXTERNAL_IDS.equals(ref);
   }
diff --git a/java/com/google/gerrit/httpd/raw/IndexHtmlUtil.java b/java/com/google/gerrit/httpd/raw/IndexHtmlUtil.java
index 72bfe40..92788b7 100644
--- a/java/com/google/gerrit/httpd/raw/IndexHtmlUtil.java
+++ b/java/com/google/gerrit/httpd/raw/IndexHtmlUtil.java
@@ -121,7 +121,7 @@
       data.put("userIsAuthenticated", true);
       if (page == RequestedPage.DASHBOARD) {
         data.put("defaultDashboardHex", ListOption.toHex(IndexPreloadingUtil.DASHBOARD_OPTIONS));
-        data.put("dashboardQuery", IndexPreloadingUtil.computeDashboardQueryList(serverApi));
+        data.put("dashboardQuery", IndexPreloadingUtil.computeDashboardQueryList());
       }
     } catch (AuthException e) {
       logger.atFine().log("Can't inline account-related data because user is unauthenticated");
diff --git a/java/com/google/gerrit/httpd/raw/IndexPreloadingUtil.java b/java/com/google/gerrit/httpd/raw/IndexPreloadingUtil.java
index bb3b6d5..afaeaf6 100644
--- a/java/com/google/gerrit/httpd/raw/IndexPreloadingUtil.java
+++ b/java/com/google/gerrit/httpd/raw/IndexPreloadingUtil.java
@@ -22,9 +22,7 @@
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.common.UsedAt;
 import com.google.gerrit.common.UsedAt.Project;
-import com.google.gerrit.extensions.api.config.Server;
 import com.google.gerrit.extensions.client.ListChangesOption;
-import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.gerrit.extensions.restapi.Url;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -188,7 +186,7 @@
     return Optional.empty();
   }
 
-  public static List<String> computeDashboardQueryList(Server serverApi) throws RestApiException {
+  public static List<String> computeDashboardQueryList() {
     List<String> queryList = new ArrayList<>();
     queryList.add(SELF_DASHBOARD_HAS_UNPUBLISHED_DRAFTS_QUERY);
     queryList.add(SELF_YOUR_TURN);
diff --git a/java/com/google/gerrit/pgm/Daemon.java b/java/com/google/gerrit/pgm/Daemon.java
index 845cc9a..744f91b 100644
--- a/java/com/google/gerrit/pgm/Daemon.java
+++ b/java/com/google/gerrit/pgm/Daemon.java
@@ -215,6 +215,7 @@
   private Path runFile;
   private boolean inMemoryTest;
   private AbstractModule indexModule;
+  private Module accountPatchReviewStoreModule;
   private Module emailModule;
   private List<Module> testSysModules = new ArrayList<>();
   private List<Module> testSshModules = new ArrayList<>();
@@ -333,6 +334,11 @@
   }
 
   @VisibleForTesting
+  public void setAccountPatchReviewStoreModuleForTesting(Module module) {
+    accountPatchReviewStoreModule = module;
+  }
+
+  @VisibleForTesting
   public void setEmailModuleForTesting(Module module) {
     emailModule = module;
   }
@@ -442,7 +448,11 @@
     modules.add(new WorkQueueModule());
     modules.add(new StreamEventsApiListenerModule());
     modules.add(new EventBrokerModule());
-    modules.add(new JdbcAccountPatchReviewStoreModule(config));
+    if (accountPatchReviewStoreModule != null) {
+      modules.add(accountPatchReviewStoreModule);
+    } else {
+      modules.add(new JdbcAccountPatchReviewStoreModule(config));
+    }
     modules.add(new SysExecutorModule());
     modules.add(new DiffExecutorModule());
     modules.add(new MimeUtil2Module());
diff --git a/java/com/google/gerrit/server/index/change/ChangeField.java b/java/com/google/gerrit/server/index/change/ChangeField.java
index 8e443f82..7984737 100644
--- a/java/com/google/gerrit/server/index/change/ChangeField.java
+++ b/java/com/google/gerrit/server/index/change/ChangeField.java
@@ -505,9 +505,11 @@
 
   /** The user assigned to the change. */
   // The getter always returns NO_ASSIGNEE, since assignee field is deprecated.
+  @Deprecated
   public static final IndexedField<ChangeData, Integer> ASSIGNEE_FIELD =
       IndexedField.<ChangeData>integerBuilder("Assignee").build(changeGetter(c -> NO_ASSIGNEE));
 
+  @Deprecated
   public static final IndexedField<ChangeData, Integer>.SearchSpec ASSIGNEE_SPEC =
       ASSIGNEE_FIELD.integer(ChangeQueryBuilder.FIELD_ASSIGNEE);
 
diff --git a/java/com/google/gerrit/server/index/change/ChangeSchemaDefinitions.java b/java/com/google/gerrit/server/index/change/ChangeSchemaDefinitions.java
index 6ddf7a3..82b8f18 100644
--- a/java/com/google/gerrit/server/index/change/ChangeSchemaDefinitions.java
+++ b/java/com/google/gerrit/server/index/change/ChangeSchemaDefinitions.java
@@ -240,6 +240,7 @@
           .build();
 
   /** Remove assignee field. */
+  @SuppressWarnings("deprecation")
   static final Schema<ChangeData> V82 =
       new Schema.Builder<ChangeData>()
           .add(V81)
diff --git a/java/com/google/gerrit/server/plugins/ServerPluginInfoModule.java b/java/com/google/gerrit/server/plugins/ServerPluginInfoModule.java
index 60dff84..e91f7b7 100644
--- a/java/com/google/gerrit/server/plugins/ServerPluginInfoModule.java
+++ b/java/com/google/gerrit/server/plugins/ServerPluginInfoModule.java
@@ -72,13 +72,15 @@
     if (!ready) {
       synchronized (dataDir) {
         if (!ready) {
-          try {
-            Files.createDirectories(dataDir);
-          } catch (IOException e) {
-            throw new ProvisionException(
-                String.format(
-                    "Cannot create %s for plugin %s", dataDir.toAbsolutePath(), plugin.getName()),
-                e);
+          if (!Files.isDirectory(dataDir)) {
+            try {
+              Files.createDirectories(dataDir);
+            } catch (IOException e) {
+              throw new ProvisionException(
+                  String.format(
+                      "Cannot create %s for plugin %s", dataDir.toAbsolutePath(), plugin.getName()),
+                  e);
+            }
           }
           ready = true;
         }
diff --git a/java/com/google/gerrit/server/restapi/BUILD b/java/com/google/gerrit/server/restapi/BUILD
index 62da2f2..dd0ec78d 100644
--- a/java/com/google/gerrit/server/restapi/BUILD
+++ b/java/com/google/gerrit/server/restapi/BUILD
@@ -34,6 +34,7 @@
         "//lib/auto:auto-factory",
         "//lib/auto:auto-value",
         "//lib/auto:auto-value-annotations",
+        "//lib/commons:codec",
         "//lib/commons:compress",
         "//lib/commons:lang3",
         "//lib/errorprone:annotations",
diff --git a/java/com/google/gerrit/server/restapi/change/ApplyPatchUtil.java b/java/com/google/gerrit/server/restapi/change/ApplyPatchUtil.java
index d4f549a..4021f77 100644
--- a/java/com/google/gerrit/server/restapi/change/ApplyPatchUtil.java
+++ b/java/com/google/gerrit/server/restapi/change/ApplyPatchUtil.java
@@ -23,6 +23,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
+import org.apache.commons.codec.binary.Base64;
 import org.eclipse.jgit.api.errors.PatchApplyException;
 import org.eclipse.jgit.api.errors.PatchFormatException;
 import org.eclipse.jgit.lib.ObjectId;
@@ -51,8 +52,12 @@
       throws IOException, RestApiException {
     checkNotNull(mergeTip);
     RevTree tip = mergeTip.getTree();
-    InputStream patchStream =
-        new ByteArrayInputStream(input.patch.getBytes(StandardCharsets.UTF_8));
+    InputStream patchStream;
+    if (Base64.isBase64(input.patch)) {
+      patchStream = new ByteArrayInputStream(org.eclipse.jgit.util.Base64.decode(input.patch));
+    } else {
+      patchStream = new ByteArrayInputStream(input.patch.getBytes(StandardCharsets.UTF_8));
+    }
     try {
       PatchApplier applier = new PatchApplier(repo, tip, oi);
       PatchApplier.Result applyResult = applier.applyPatch(patchStream);
diff --git a/java/com/google/gerrit/server/update/context/RefUpdateContext.java b/java/com/google/gerrit/server/update/context/RefUpdateContext.java
index 3ac0f0d..1144e4f 100644
--- a/java/com/google/gerrit/server/update/context/RefUpdateContext.java
+++ b/java/com/google/gerrit/server/update/context/RefUpdateContext.java
@@ -22,7 +22,7 @@
 import java.util.Deque;
 
 /**
- * Passes additional information about an operation to the {@link BatchRefUpdate#execute} method.
+ * Passes additional information about an operation to the {@code BatchRefUpdate#execute} method.
  *
  * <p>To pass the additional information {@link RefUpdateContext}, wraps a code into an open
  * RefUpdateContext, e.g.:
@@ -34,7 +34,7 @@
  * }
  * }</pre>
  *
- * When the {@link BatchRefUpdate#execute} method is executed, it can get all opened contexts and
+ * When the {@code BatchRefUpdate#execute} method is executed, it can get all opened contexts and
  * use it for an additional actions, e.g. it can put it in the reflog.
  *
  * <p>The information provided by this class is used internally in google.
@@ -42,7 +42,7 @@
  * <p>The InMemoryRepositoryManager file makes some validation to ensure that RefUpdateContext is
  * used correctly within the code (see thee validateRefUpdateContext method).
  *
- * <p>The class includes only operations from open-source gerrit and can be extended (see {@link
+ * <p>The class includes only operations from open-source gerrit and can be extended (see {@code
  * TestActionRefUpdateContext} for example how to extend it).
  */
 public class RefUpdateContext implements AutoCloseable {
diff --git a/java/com/google/gerrit/testing/BUILD b/java/com/google/gerrit/testing/BUILD
index fb9e64e..81a6443 100644
--- a/java/com/google/gerrit/testing/BUILD
+++ b/java/com/google/gerrit/testing/BUILD
@@ -51,6 +51,7 @@
         "//lib:junit",
         "//lib/auto:auto-value",
         "//lib/auto:auto-value-annotations",
+        "//lib/errorprone:annotations",
         "//lib/flogger:api",
         "//lib/guice",
         "//lib/guice:guice-servlet",
diff --git a/java/com/google/gerrit/testing/FakeAccountPatchReviewStore.java b/java/com/google/gerrit/testing/FakeAccountPatchReviewStore.java
new file mode 100644
index 0000000..1533aeb
--- /dev/null
+++ b/java/com/google/gerrit/testing/FakeAccountPatchReviewStore.java
@@ -0,0 +1,141 @@
+// Copyright (C) 2023 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.testing;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableSet;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
+import com.google.gerrit.entities.Account;
+import com.google.gerrit.entities.Change;
+import com.google.gerrit.entities.PatchSet;
+import com.google.gerrit.extensions.events.LifecycleListener;
+import com.google.gerrit.extensions.registration.DynamicItem;
+import com.google.gerrit.lifecycle.LifecycleModule;
+import com.google.gerrit.server.change.AccountPatchReviewStore;
+import com.google.inject.Singleton;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * An implementation of the {@link AccountPatchReviewStore} that's only used in tests. This
+ * implementation stores reviewed files in memory.
+ */
+@Singleton
+public class FakeAccountPatchReviewStore implements AccountPatchReviewStore, LifecycleListener {
+
+  private final Set<Entity> store = new HashSet<>();
+
+  @Override
+  public void start() {}
+
+  @Override
+  public void stop() {}
+
+  public static class FakeAccountPatchReviewStoreModule extends LifecycleModule {
+    @Override
+    protected void configure() {
+      DynamicItem.bind(binder(), AccountPatchReviewStore.class)
+          .to(FakeAccountPatchReviewStore.class);
+      listener().to(FakeAccountPatchReviewStore.class);
+    }
+  }
+
+  @AutoValue
+  abstract static class Entity {
+    abstract PatchSet.Id psId();
+
+    abstract Account.Id accountId();
+
+    abstract String path();
+
+    static Entity create(PatchSet.Id psId, Account.Id accountId, String path) {
+      return new AutoValue_FakeAccountPatchReviewStore_Entity(psId, accountId, path);
+    }
+  }
+
+  @Override
+  @CanIgnoreReturnValue
+  public boolean markReviewed(PatchSet.Id psId, Account.Id accountId, String path) {
+    synchronized (store) {
+      Entity entity = Entity.create(psId, accountId, path);
+      return store.add(entity);
+    }
+  }
+
+  @Override
+  public void markReviewed(PatchSet.Id psId, Account.Id accountId, Collection<String> paths) {
+    paths.forEach(path -> markReviewed(psId, accountId, path));
+  }
+
+  @Override
+  public void clearReviewed(PatchSet.Id psId, Account.Id accountId, String path) {
+    synchronized (store) {
+      store.remove(Entity.create(psId, accountId, path));
+    }
+  }
+
+  @Override
+  public void clearReviewed(PatchSet.Id psId) {
+    synchronized (store) {
+      List<Entity> toRemove = new ArrayList<>();
+      for (Entity entity : store) {
+        if (entity.psId().equals(psId)) {
+          toRemove.add(entity);
+        }
+      }
+      store.removeAll(toRemove);
+    }
+  }
+
+  @Override
+  public void clearReviewed(Change.Id changeId) {
+    synchronized (store) {
+      List<Entity> toRemove = new ArrayList<>();
+      for (Entity entity : store) {
+        if (entity.psId().changeId().equals(changeId)) {
+          toRemove.add(entity);
+        }
+      }
+      store.removeAll(toRemove);
+    }
+  }
+
+  @Override
+  public Optional<PatchSetWithReviewedFiles> findReviewed(PatchSet.Id psId, Account.Id accountId) {
+    synchronized (store) {
+      int matchedPsNumber = -1;
+      Optional<PatchSetWithReviewedFiles> result = Optional.empty();
+      for (Entity entity : store) {
+        if (entity.accountId() != accountId || !entity.psId().changeId().equals(psId.changeId())) {
+          continue;
+        }
+        int entityPsNumber = Integer.parseInt(entity.psId().getId());
+        if (entityPsNumber <= psId.get() && entityPsNumber > matchedPsNumber) {
+          matchedPsNumber = entityPsNumber;
+          result =
+              Optional.of(
+                  PatchSetWithReviewedFiles.create(
+                      PatchSet.id(psId.changeId(), matchedPsNumber),
+                      ImmutableSet.of(entity.path())));
+        }
+      }
+      return result;
+    }
+  }
+}
diff --git a/java/com/google/gerrit/testing/InMemoryRepositoryManager.java b/java/com/google/gerrit/testing/InMemoryRepositoryManager.java
index 650c218..8d1130c 100644
--- a/java/com/google/gerrit/testing/InMemoryRepositoryManager.java
+++ b/java/com/google/gerrit/testing/InMemoryRepositoryManager.java
@@ -171,7 +171,7 @@
       private RefUpdateContextValidator addSpecialRef(
           Predicate<String> refNamePredicate, RefUpdateType... validRefUpdateTypes) {
         specialRefs.add(
-            new SimpleImmutableEntry<Predicate<String>, ImmutableList<RefUpdateType>>(
+            new SimpleImmutableEntry<>(
                 refNamePredicate, ImmutableList.copyOf(validRefUpdateTypes)));
         return this;
       }
diff --git a/javatests/com/google/gerrit/acceptance/TestMetricMakerTest.java b/javatests/com/google/gerrit/acceptance/TestMetricMakerTest.java
new file mode 100644
index 0000000..3464d21
--- /dev/null
+++ b/javatests/com/google/gerrit/acceptance/TestMetricMakerTest.java
@@ -0,0 +1,202 @@
+// Copyright (C) 2023 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;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.gerrit.metrics.Counter0;
+import com.google.gerrit.metrics.Counter1;
+import com.google.gerrit.metrics.Counter2;
+import com.google.gerrit.metrics.Counter3;
+import com.google.gerrit.metrics.Description;
+import com.google.gerrit.metrics.Field;
+import org.junit.Before;
+import org.junit.Test;
+
+/** Tests for {@link TestMetricMaker}. */
+public class TestMetricMakerTest {
+  private TestMetricMaker testMetricMaker = new TestMetricMaker();
+
+  @Before
+  public void setUp() {
+    testMetricMaker.reset();
+  }
+
+  @Test
+  public void counter0() throws Exception {
+    String counterName = "test_counter";
+    Counter0 counter = testMetricMaker.newCounter(counterName, new Description("Test Counter"));
+    assertThat(testMetricMaker.getCount(counterName)).isEqualTo(0);
+
+    counter.increment();
+    assertThat(testMetricMaker.getCount(counterName)).isEqualTo(1);
+
+    counter.incrementBy(/* value= */ 3);
+    assertThat(testMetricMaker.getCount(counterName)).isEqualTo(4);
+  }
+
+  @Test
+  public void counter1_booleanField() throws Exception {
+    String counterName = "test_counter";
+    Counter1<Boolean> counter =
+        testMetricMaker.newCounter(
+            counterName,
+            new Description("Test Counter"),
+            Field.ofBoolean("boolean_field", (metadataBuilder, booleanField) -> {}).build());
+    assertThat(testMetricMaker.getCount(counterName, true)).isEqualTo(0);
+    assertThat(testMetricMaker.getCount(counterName, false)).isEqualTo(0);
+
+    counter.increment(/* field1= */ true);
+    assertThat(testMetricMaker.getCount(counterName, true)).isEqualTo(1);
+    assertThat(testMetricMaker.getCount(counterName, false)).isEqualTo(0);
+
+    counter.incrementBy(/* field1= */ true, /* value= */ 3);
+    assertThat(testMetricMaker.getCount(counterName, true)).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false)).isEqualTo(0);
+
+    counter.increment(/* field1= */ false);
+    assertThat(testMetricMaker.getCount(counterName, true)).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false)).isEqualTo(1);
+
+    counter.incrementBy(/* field1= */ false, /* value= */ 4);
+    assertThat(testMetricMaker.getCount(counterName, true)).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false)).isEqualTo(5);
+
+    assertThat(testMetricMaker.getCount(counterName)).isEqualTo(0);
+  }
+
+  @Test
+  public void counter1_stringField() throws Exception {
+    String counterName = "test_counter";
+    Counter1<String> counter =
+        testMetricMaker.newCounter(
+            counterName,
+            new Description("Test Counter"),
+            Field.ofString("string_field", (metadataBuilder, stringField) -> {}).build());
+    assertThat(testMetricMaker.getCount(counterName, "foo")).isEqualTo(0);
+    assertThat(testMetricMaker.getCount(counterName, "bar")).isEqualTo(0);
+
+    counter.increment(/* field1= */ "foo");
+    assertThat(testMetricMaker.getCount(counterName, "foo")).isEqualTo(1);
+    assertThat(testMetricMaker.getCount(counterName, "bar")).isEqualTo(0);
+
+    counter.incrementBy(/* field1= */ "foo", /* value= */ 3);
+    assertThat(testMetricMaker.getCount(counterName, "foo")).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, "bar")).isEqualTo(0);
+
+    counter.increment(/* field1= */ "bar");
+    assertThat(testMetricMaker.getCount(counterName, "foo")).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, "bar")).isEqualTo(1);
+
+    counter.incrementBy(/* field1= */ "bar", /* value= */ 4);
+    assertThat(testMetricMaker.getCount(counterName, "foo")).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, "bar")).isEqualTo(5);
+
+    assertThat(testMetricMaker.getCount(counterName)).isEqualTo(0);
+  }
+
+  @Test
+  public void counter2() throws Exception {
+    String counterName = "test_counter";
+    Counter2<Boolean, String> counter =
+        testMetricMaker.newCounter(
+            counterName,
+            new Description("Test Counter"),
+            Field.ofBoolean("boolean_field", (metadataBuilder, booleanField) -> {}).build(),
+            Field.ofString("string_field", (metadataBuilder, stringField) -> {}).build());
+    assertThat(testMetricMaker.getCount(counterName, true, "foo")).isEqualTo(0);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo")).isEqualTo(0);
+
+    counter.increment(/* field1= */ true, /* field2= */ "foo");
+    assertThat(testMetricMaker.getCount(counterName, true, "foo")).isEqualTo(1);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo")).isEqualTo(0);
+
+    counter.incrementBy(/* field1= */ true, /* field2= */ "foo", /* value= */ 3);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo")).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo")).isEqualTo(0);
+
+    counter.increment(/* field1= */ false, /* field2= */ "foo");
+    assertThat(testMetricMaker.getCount(counterName, true, "foo")).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo")).isEqualTo(1);
+
+    counter.incrementBy(/* field1= */ false, /* field2= */ "foo", /* value= */ 4);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo")).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo")).isEqualTo(5);
+
+    counter.increment(/* field1= */ true, /* field2= */ "bar");
+    assertThat(testMetricMaker.getCount(counterName, true, "foo")).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, true, "bar")).isEqualTo(1);
+
+    counter.incrementBy(/* field1= */ true, /* field2= */ "bar", /* value= */ 5);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo")).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, true, "bar")).isEqualTo(6);
+
+    assertThat(testMetricMaker.getCount(counterName)).isEqualTo(0);
+    assertThat(testMetricMaker.getCount(counterName, true)).isEqualTo(0);
+    assertThat(testMetricMaker.getCount(counterName, false)).isEqualTo(0);
+  }
+
+  @Test
+  public void counter3() throws Exception {
+    String counterName = "test_counter";
+    Counter3<Boolean, String, Integer> counter =
+        testMetricMaker.newCounter(
+            counterName,
+            new Description("Test Counter"),
+            Field.ofBoolean("boolean_field", (metadataBuilder, booleanField) -> {}).build(),
+            Field.ofString("string_field", (metadataBuilder, stringField) -> {}).build(),
+            Field.ofInteger("integer_field", (metadataBuilder, stringField) -> {}).build());
+    assertThat(testMetricMaker.getCount(counterName, true, "foo", 0)).isEqualTo(0);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo", 0)).isEqualTo(0);
+
+    counter.increment(/* field1= */ true, /* field2= */ "foo", /* field3= */ 0);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo", 0)).isEqualTo(1);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo", 0)).isEqualTo(0);
+
+    counter.incrementBy(/* field1= */ true, /* field2= */ "foo", /* field3= */ 0, /* value= */ 3);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo", 0)).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo", 0)).isEqualTo(0);
+
+    counter.increment(/* field1= */ false, /* field2= */ "foo", /* field3= */ 0);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo", 0)).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo", 0)).isEqualTo(1);
+
+    counter.incrementBy(/* field1= */ false, /* field2= */ "foo", /* field3= */ 0, /* value= */ 4);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo", 0)).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo", 0)).isEqualTo(5);
+
+    counter.increment(/* field1= */ true, /* field2= */ "bar", /* field3= */ 0);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo", 0)).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, true, "bar", 0)).isEqualTo(1);
+
+    counter.incrementBy(/* field1= */ true, /* field2= */ "bar", /* field3= */ 0, /* value= */ 5);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo", 0)).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, true, "bar", 0)).isEqualTo(6);
+
+    counter.increment(/* field1= */ false, /* field2= */ "foo", /* field3= */ 1);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo", 0)).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo", 1)).isEqualTo(1);
+
+    counter.incrementBy(/* field1= */ false, /* field2= */ "foo", /* field3= */ 1, /* value= */ 6);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo", 0)).isEqualTo(4);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo", 1)).isEqualTo(7);
+
+    assertThat(testMetricMaker.getCount(counterName)).isEqualTo(0);
+    assertThat(testMetricMaker.getCount(counterName, true)).isEqualTo(0);
+    assertThat(testMetricMaker.getCount(counterName, false)).isEqualTo(0);
+    assertThat(testMetricMaker.getCount(counterName, true, "foo")).isEqualTo(0);
+    assertThat(testMetricMaker.getCount(counterName, false, "foo")).isEqualTo(0);
+  }
+}
diff --git a/javatests/com/google/gerrit/acceptance/api/change/ApplyPatchIT.java b/javatests/com/google/gerrit/acceptance/api/change/ApplyPatchIT.java
index 898e1ff..0b55563 100644
--- a/javatests/com/google/gerrit/acceptance/api/change/ApplyPatchIT.java
+++ b/javatests/com/google/gerrit/acceptance/api/change/ApplyPatchIT.java
@@ -213,6 +213,29 @@
   }
 
   @Test
+  public void applyGerritBasedPatchUsingRestWithEncodedPatch_success() throws Exception {
+    String head = getHead(repo(), HEAD).name();
+    createBranchWithRevision(BranchNameKey.create(project, "branch"), head);
+    PushOneCommit.Result baseCommit = createChange("Add file", ADDED_FILE_NAME, ADDED_FILE_CONTENT);
+    baseCommit.assertOkStatus();
+    createBranchWithRevision(BranchNameKey.create(project, DESTINATION_BRANCH), head);
+    RestResponse patchResp =
+        userRestSession.get("/changes/" + baseCommit.getChangeId() + "/revisions/current/patch");
+    patchResp.assertOK();
+    String originalEncodedPatch = patchResp.getEntityContent();
+    String originalDecodedPatch = new String(Base64.decode(patchResp.getEntityContent()), UTF_8);
+    ApplyPatchPatchSetInput in = buildInput(originalEncodedPatch);
+    PushOneCommit.Result destChange = createChange();
+
+    RestResponse resp =
+        adminRestSession.post("/changes/" + destChange.getChangeId() + "/patch:apply", in);
+
+    resp.assertOK();
+    BinaryResult resultPatch = gApi.changes().id(destChange.getChangeId()).current().patch();
+    assertThat(removeHeader(resultPatch)).isEqualTo(removeHeader(originalDecodedPatch));
+  }
+
+  @Test
   public void applyPatchWithConflict_fails() throws Exception {
     initBaseWithFile(MODIFIED_FILE_NAME, "Unexpected base content");
     ApplyPatchPatchSetInput in = buildInput(MODIFIED_FILE_DIFF);
@@ -404,6 +427,6 @@
   }
 
   private String removeHeader(String s) {
-    return s.substring(s.indexOf("\ndiff --git"), s.length() - 1);
+    return s.substring(s.lastIndexOf("\ndiff --git"), s.length() - 1);
   }
 }
diff --git a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts
index 721d650..bb27237 100644
--- a/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts
+++ b/polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.ts
@@ -1244,7 +1244,6 @@
       <div class="changeStatuses">
         ${this.changeStatuses.map(
           status => html` <gr-change-status
-            .change=${this.change}
             .revertedChange=${this.revertedChange}
             .status=${status}
             .resolveWeblinks=${resolveWeblinks}
diff --git a/polygerrit-ui/app/elements/change/gr-confirm-rebase-dialog/gr-confirm-rebase-dialog.ts b/polygerrit-ui/app/elements/change/gr-confirm-rebase-dialog/gr-confirm-rebase-dialog.ts
index c2739f3..ad2ba8f 100644
--- a/polygerrit-ui/app/elements/change/gr-confirm-rebase-dialog/gr-confirm-rebase-dialog.ts
+++ b/polygerrit-ui/app/elements/change/gr-confirm-rebase-dialog/gr-confirm-rebase-dialog.ts
@@ -22,7 +22,6 @@
 import {sharedStyles} from '../../../styles/shared-styles';
 import {ValueChangedEvent} from '../../../types/events';
 import {throwingErrorCallback} from '../../shared/gr-rest-api-interface/gr-rest-apis/gr-rest-api-helper';
-import {KnownExperimentId} from '../../../services/flags/flags';
 
 export interface RebaseChange {
   name: string;
@@ -99,8 +98,6 @@
 
   private readonly restApiService = getAppContext().restApiService;
 
-  private readonly flagsService = getAppContext().flagsService;
-
   constructor() {
     super();
     this.query = input => this.getChangeSuggestions(input);
@@ -234,8 +231,7 @@
             >
           </div>
           ${when(
-            this.flagsService.isEnabled(KnownExperimentId.REBASE_CHAIN) &&
-              this.hasParent,
+            this.hasParent,
             () =>
               html`<div>
                 <input
diff --git a/polygerrit-ui/app/elements/change/gr-label-scores/gr-label-scores.ts b/polygerrit-ui/app/elements/change/gr-label-scores/gr-label-scores.ts
index 873e6ce..3a83fa1 100644
--- a/polygerrit-ui/app/elements/change/gr-label-scores/gr-label-scores.ts
+++ b/polygerrit-ui/app/elements/change/gr-label-scores/gr-label-scores.ts
@@ -5,7 +5,7 @@
  */
 import '../gr-label-score-row/gr-label-score-row';
 import '../../../styles/shared-styles';
-import {LitElement, css, html} from 'lit';
+import {LitElement, css, html, nothing} from 'lit';
 import {customElement, property} from 'lit/decorators.js';
 import {
   ChangeInfo,
@@ -107,8 +107,7 @@
         label => !this.permittedLabels || this.permittedLabels[label.name]
       ).length === 0
     ) {
-      return html`<h3 class="heading-4">Trigger Votes</h3>
-        <div class="permissionMessage">You don't have permission to vote</div>`;
+      return nothing;
     }
     return html`<h3 class="heading-4">Trigger Votes</h3>
       ${this.renderLabels(labels)}`;
diff --git a/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar.ts b/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar.ts
index fbc87ed..314e126 100644
--- a/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar.ts
+++ b/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar.ts
@@ -278,7 +278,7 @@
     // fallback to gerrit's official doc
     let baseUrl =
       this.docsBaseUrl ||
-      'https://gerrit-review.googlesource.com/documentation/';
+      'https://gerrit-review.googlesource.com/Documentation/';
     if (baseUrl.endsWith('/')) {
       baseUrl = baseUrl.substring(0, baseUrl.length - 1);
     }
diff --git a/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts b/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts
index 43b1f86..0694453 100644
--- a/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts
+++ b/polygerrit-ui/app/elements/core/gr-search-bar/gr-search-bar_test.ts
@@ -319,7 +319,7 @@
       await element.updateComplete;
       assert.equal(
         element.computeHelpDocLink(),
-        'https://gerrit-review.googlesource.com/documentation/' +
+        'https://gerrit-review.googlesource.com/Documentation/' +
           'user-search.html'
       );
     });
diff --git a/polygerrit-ui/app/elements/gr-app-element.ts b/polygerrit-ui/app/elements/gr-app-element.ts
index b096f76..e5991f6 100644
--- a/polygerrit-ui/app/elements/gr-app-element.ts
+++ b/polygerrit-ui/app/elements/gr-app-element.ts
@@ -500,11 +500,12 @@
   }
 
   private renderEditorView() {
-    // The `cache()` is required for re-using the editor view when switching
-    // back and forth between change, diff and editor views.
-    return cache(
-      this.isEditorView() ? html`<gr-editor-view></gr-editor-view>` : nothing
-    );
+    // For some reason caching the editor view caused an issue (b/269308770).
+    // We did not bother to root cause that issue, but instead let's forgo
+    // caching of the editor view. It does not help much anyway.
+    return this.isEditorView()
+      ? html`<gr-editor-view></gr-editor-view>`
+      : nothing;
   }
 
   private isEditorView() {
diff --git a/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown.ts b/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown.ts
index 91e601c..661ffa0 100644
--- a/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown.ts
+++ b/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown.ts
@@ -35,6 +35,16 @@
   selected: HTMLElement | null;
 }
 
+export enum AutocompleteQueryStatusType {
+  LOADING = 'loading',
+  ERROR = 'error',
+}
+
+export interface AutocompleteQueryStatus {
+  type: AutocompleteQueryStatusType;
+  message: string;
+}
+
 @customElement('gr-autocomplete-dropdown')
 export class GrAutocompleteDropdown extends LitElement {
   /**
@@ -58,8 +68,8 @@
   /** If specified a single non-interactable line is shown instead of
    * suggestions.
    */
-  @property({type: String})
-  errorMessage?: String;
+  @property({type: Object})
+  queryStatus?: AutocompleteQueryStatus;
 
   @property({type: Number})
   verticalOffset = 0;
@@ -117,10 +127,12 @@
         li.selected {
           background-color: var(--hover-background-color);
         }
-        li.query-error {
+        li.query-status {
           background-color: var(--disabled-background);
-          color: var(--error-foreground);
           cursor: default;
+        }
+        li.query-status.error {
+          color: var(--error-foreground);
           white-space: pre-wrap;
         }
         @media only screen and (max-height: 35em) {
@@ -140,7 +152,7 @@
   }
 
   private isSuggestionListInteractible() {
-    return !this.isHidden && !this.errorMessage;
+    return !this.isHidden && !this.queryStatus;
   }
 
   constructor() {
@@ -172,7 +184,8 @@
   override updated(changedProperties: PropertyValues) {
     if (
       changedProperties.has('suggestions') ||
-      changedProperties.has('isHidden')
+      changedProperties.has('isHidden') ||
+      changedProperties.has('queryStatus')
     ) {
       if (!this.isHidden) {
         this.computeCursorStopsAndRefit();
@@ -180,15 +193,19 @@
     }
   }
 
-  private renderError() {
+  private renderStatus() {
     return html`
       <li
         tabindex="-1"
-        aria-label="autocomplete query error"
-        class="query-error"
+        aria-label="autocomplete query status"
+        class="query-status ${this.queryStatus?.type}"
       >
-        <span>${this.errorMessage}</span>
-        <span class="label">ERROR</span>
+        <span>${this.queryStatus?.message}</span>
+        <span class="label"
+          >${this.queryStatus?.type === AutocompleteQueryStatusType.ERROR
+            ? 'ERROR'
+            : ''}</span
+        >
       </li>
     `;
   }
@@ -198,8 +215,8 @@
       <div class="dropdown-content" id="suggestions" role="listbox">
         <ul>
           ${when(
-            this.errorMessage,
-            () => this.renderError(),
+            this.queryStatus,
+            () => this.renderStatus(),
             () => html`
               ${repeat(
                 this.suggestions,
@@ -236,7 +253,7 @@
   }
 
   getCurrentText() {
-    if (!this.errorMessage) {
+    if (!this.queryStatus) {
       return this.getCursorTarget()?.dataset['value'] || '';
     }
     return '';
diff --git a/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown_test.ts b/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown_test.ts
index 54d054b..10ba5d0 100644
--- a/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-autocomplete-dropdown/gr-autocomplete-dropdown_test.ts
@@ -5,7 +5,10 @@
  */
 import '../../../test/common-test-setup';
 import './gr-autocomplete-dropdown';
-import {GrAutocompleteDropdown} from './gr-autocomplete-dropdown';
+import {
+  AutocompleteQueryStatusType,
+  GrAutocompleteDropdown,
+} from './gr-autocomplete-dropdown';
 import {
   pressKey,
   queryAll,
@@ -177,7 +180,7 @@
     });
   });
 
-  suite('error tests', () => {
+  suite('status tests', () => {
     let element: GrAutocompleteDropdown;
 
     setup(async () => {
@@ -185,7 +188,10 @@
         html`<gr-autocomplete-dropdown></gr-autocomplete-dropdown>`
       );
       element.open();
-      element.errorMessage = 'Failed query error';
+      element.queryStatus = {
+        type: AutocompleteQueryStatusType.ERROR,
+        message: 'Failed query error',
+      };
       await waitEventLoop();
     });
 
@@ -200,8 +206,8 @@
           <div class="dropdown-content" id="suggestions" role="listbox">
             <ul>
               <li
-                aria-label="autocomplete query error"
-                class="query-error"
+                aria-label="autocomplete query status"
+                class="query-status error"
                 tabindex="-1"
               >
                 <span>Failed query error</span>
@@ -213,6 +219,31 @@
       );
     });
 
+    test('renders loading', async () => {
+      element.queryStatus = {
+        type: AutocompleteQueryStatusType.LOADING,
+        message: 'Loading...',
+      };
+      await waitEventLoop();
+      assert.shadowDom.equal(
+        element,
+        /* HTML */ `
+          <div class="dropdown-content" id="suggestions" role="listbox">
+            <ul>
+              <li
+                aria-label="autocomplete query status"
+                class="query-status loading"
+                tabindex="-1"
+              >
+                <span>Loading...</span>
+                <span class="label"></span>
+              </li>
+            </ul>
+          </div>
+        `
+      );
+    });
+
     test('escape key close dropdown with error', async () => {
       const closeSpy = sinon.spy(element, 'close');
       pressKey(element, Key.ESC);
diff --git a/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.ts b/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.ts
index ab74e8b..db0d236 100644
--- a/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.ts
+++ b/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete.ts
@@ -7,7 +7,11 @@
 import '../gr-autocomplete-dropdown/gr-autocomplete-dropdown';
 import '../gr-cursor-manager/gr-cursor-manager';
 import '../../../styles/shared-styles';
-import {GrAutocompleteDropdown} from '../gr-autocomplete-dropdown/gr-autocomplete-dropdown';
+import {
+  AutocompleteQueryStatus,
+  AutocompleteQueryStatusType,
+  GrAutocompleteDropdown,
+} from '../gr-autocomplete-dropdown/gr-autocomplete-dropdown';
 import {fire, fireEvent} from '../../../utils/event-util';
 import {
   debounce,
@@ -166,7 +170,7 @@
 
   @state() suggestions: AutocompleteSuggestion[] = [];
 
-  @state() queryErrorMessage?: string;
+  @state() queryStatus?: AutocompleteQueryStatus;
 
   @state() index: number | null = null;
 
@@ -179,8 +183,23 @@
 
   @state() selected: HTMLElement | null = null;
 
+  /**
+   * The query id that status or suggestions correspond to.
+   */
+  private activeQueryId = 0;
+
+  /**
+   * Last scheduled update suggestions task.
+   */
   private updateSuggestionsTask?: DelayedTask;
 
+  // Generate ids for scheduled suggestion queries to easily distinguish them.
+  private static NEXT_QUERY_ID = 1;
+
+  private static getNextQueryId() {
+    return GrAutocomplete.NEXT_QUERY_ID++;
+  }
+
   /**
    * @return Promise that resolves when suggestions are update.
    */
@@ -266,7 +285,7 @@
     }
     if (
       changedProperties.has('suggestions') ||
-      changedProperties.has('queryErrorMessage')
+      changedProperties.has('queryStatus')
     ) {
       this.updateDropdownVisibility();
     }
@@ -310,7 +329,7 @@
         @item-selected=${this.handleItemSelect}
         @dropdown-closed=${this.focusWithoutDisplayingSuggestions}
         .suggestions=${this.suggestions}
-        .errorMessage=${this.queryErrorMessage}
+        .queryStatus=${this.queryStatus}
         role="listbox"
         .index=${this.index}
       >
@@ -412,8 +431,7 @@
     // Reset suggestions for every update
     // This will also prevent from carrying over suggestions:
     // @see Issue 12039
-    this.suggestions = [];
-    this.queryErrorMessage = undefined;
+    this.resetQueryOutput();
 
     // TODO(taoalpha): Also skip if text has not changed
 
@@ -421,8 +439,7 @@
       return;
     }
 
-    const query = this.query;
-    if (!query) {
+    if (!this.query) {
       return;
     }
 
@@ -435,49 +452,69 @@
       return;
     }
 
-    const update = () => {
-      query(this.text)
-        .then(suggestions => {
-          if (this.text !== this.text) {
-            // Late response.
-            return;
-          }
-          for (const suggestion of suggestions) {
-            suggestion.text = suggestion?.name ?? '';
-          }
-          this.suggestions = suggestions;
-          if (this.index === -1) {
-            this.value = '';
-          }
-        })
-        .catch(e => {
-          this.value = '';
-          if (typeof e === 'string') {
-            this.queryErrorMessage = e;
-          } else if (e instanceof Error) {
-            this.queryErrorMessage = e.message;
-          }
-        });
-    };
-
+    const queryId = GrAutocomplete.getNextQueryId();
+    this.activeQueryId = queryId;
+    this.setQueryStatus({
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading...',
+    });
     this.updateSuggestionsTask = debounce(
       this.updateSuggestionsTask,
-      update,
+      this.createUpdateTask(queryId, this.query, this.text),
       DEBOUNCE_WAIT_MS
     );
   }
 
+  private createUpdateTask(
+    queryId: number,
+    query: AutocompleteQuery,
+    text: string
+  ): () => Promise<void> {
+    return async () => {
+      let suggestions: AutocompleteSuggestion[];
+      try {
+        suggestions = await query(text);
+      } catch (e) {
+        this.value = '';
+        if (typeof e === 'string') {
+          this.setQueryStatus({
+            type: AutocompleteQueryStatusType.ERROR,
+            message: e,
+          });
+        } else if (e instanceof Error) {
+          this.setQueryStatus({
+            type: AutocompleteQueryStatusType.ERROR,
+            message: e.message,
+          });
+        }
+        return;
+      }
+      if (queryId !== this.activeQueryId) {
+        // Late response.
+        return;
+      }
+      for (const suggestion of suggestions) {
+        suggestion.text = suggestion?.name ?? '';
+      }
+      this.setSuggestions(suggestions);
+      if (this.index === -1) {
+        this.value = '';
+      }
+    };
+  }
+
   setFocus(focused: boolean) {
     if (focused === this.focused) return;
     this.focused = focused;
     this.updateDropdownVisibility();
   }
 
+  private shouldShowDropdown() {
+    return (this.suggestions.length > 0 || this.queryStatus) && this.focused;
+  }
+
   updateDropdownVisibility() {
-    if (
-      (this.suggestions.length > 0 || this.queryErrorMessage) &&
-      this.focused
-    ) {
+    if (this.shouldShowDropdown()) {
       this.suggestionsDropdown?.open();
       return;
     }
@@ -510,10 +547,26 @@
         this.cancel();
         break;
       case 'Tab':
-        if (this.suggestions.length > 0 && this.tabComplete) {
+        if (
+          this.queryStatus?.type === AutocompleteQueryStatusType.LOADING &&
+          this.tabComplete
+        ) {
           e.preventDefault();
+          // Queue tab on load.
+          this.queryStatus = {
+            type: AutocompleteQueryStatusType.LOADING,
+            message: 'Loading... (Handle Tab on load)',
+          };
+          const queryId = this.activeQueryId;
+          this.latestSuggestionUpdateComplete?.then(() => {
+            if (queryId === this.activeQueryId) {
+              this.handleInputCommit(/* _tabComplete=*/ true);
+            }
+          });
+        } else if (this.suggestions.length > 0 && this.tabComplete) {
+          e.preventDefault();
+          this.handleInputCommit(/* _tabComplete=*/ true);
           this.focus();
-          this.handleInputCommit(true);
         } else {
           this.setFocus(false);
         }
@@ -522,12 +575,24 @@
         if (modifierPressed(e)) {
           break;
         }
-        if (this.suggestions.length > 0) {
+        e.preventDefault();
+        if (this.queryStatus?.type === AutocompleteQueryStatusType.LOADING) {
+          // Queue enter on load.
+          this.queryStatus = {
+            type: AutocompleteQueryStatusType.LOADING,
+            message: 'Loading... (Handle Enter on load)',
+          };
+          const queryId = this.activeQueryId;
+          this.latestSuggestionUpdateComplete?.then(() => {
+            if (queryId === this.activeQueryId) {
+              this.handleItemSelectEnter(e);
+            }
+          });
+        } else if (this.suggestions.length > 0) {
           // If suggestions are shown, act as if the keypress is in dropdown.
           // suggestions length is 0 if error is shown.
           this.handleItemSelectEnter(e);
         } else {
-          e.preventDefault();
           this.handleInputCommit();
         }
         break;
@@ -540,7 +605,8 @@
         // been based on a previous input. Clear them. This prevents an
         // outdated suggestion from being used if the input keystroke is
         // immediately followed by a commit keystroke. @see Issue 8655
-        this.suggestions = [];
+        this.resetQueryOutput();
+        this.activeQueryId = 0;
     }
     this.dispatchEvent(
       new CustomEvent('input-keydown', {
@@ -552,9 +618,11 @@
   }
 
   cancel() {
-    if (this.suggestions.length || this.queryErrorMessage) {
-      this.suggestions = [];
-      this.queryErrorMessage = undefined;
+    if (this.shouldShowDropdown()) {
+      this.resetQueryOutput();
+      // If query is in flight by setting id to 0 we indicate that the results
+      // are outdated.
+      this.activeQueryId = 0;
       this.requestUpdate();
     } else {
       fireEvent(this, 'cancel');
@@ -565,7 +633,7 @@
     // Nothing to do if no suggestions.
     if (
       !this.allowNonSuggestedValues &&
-      (this.suggestionsDropdown?.isHidden || this.queryErrorMessage)
+      (this.suggestionsDropdown?.isHidden || this.suggestions.length === 0)
     ) {
       return;
     }
@@ -607,6 +675,7 @@
       }
     }
     this.setFocus(false);
+    this.activeQueryId = 0;
   };
 
   /**
@@ -643,8 +712,7 @@
       }
     }
 
-    this.suggestions = [];
-    this.queryErrorMessage = undefined;
+    this.resetQueryOutput();
     // we need willUpdate to send text-changed event before we can send the
     // 'commit' event
     await this.updateComplete;
@@ -658,6 +726,23 @@
       );
     }
   }
+
+  // resetQueryOutput, setSuggestions and setQueryStatus insure that suggestions
+  // and queryStatus are never set at the same time.
+  private resetQueryOutput() {
+    this.suggestions = [];
+    this.queryStatus = undefined;
+  }
+
+  private setSuggestions(suggestions: AutocompleteSuggestion[]) {
+    this.suggestions = suggestions;
+    this.queryStatus = undefined;
+  }
+
+  private setQueryStatus(queryStatus: AutocompleteQueryStatus) {
+    this.suggestions = [];
+    this.queryStatus = queryStatus;
+  }
 }
 
 /**
diff --git a/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete_test.ts b/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete_test.ts
index 81949c7..c59b8e8 100644
--- a/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-autocomplete/gr-autocomplete_test.ts
@@ -8,11 +8,15 @@
 import {AutocompleteSuggestion, GrAutocomplete} from './gr-autocomplete';
 import {
   assertFails,
+  mockPromise,
   pressKey,
   queryAndAssert,
   waitUntil,
 } from '../../../test/test-utils';
-import {GrAutocompleteDropdown} from '../gr-autocomplete-dropdown/gr-autocomplete-dropdown';
+import {
+  AutocompleteQueryStatusType,
+  GrAutocompleteDropdown,
+} from '../gr-autocomplete-dropdown/gr-autocomplete-dropdown';
 import {PaperInputElement} from '@polymer/paper-input/paper-input';
 import {fixture, html, assert} from '@open-wc/testing';
 import {Key, Modifier} from '../../../utils/dom-util';
@@ -30,9 +34,7 @@
   const inputEl = () => queryAndAssert<HTMLInputElement>(element, '#input');
 
   setup(async () => {
-    element = await fixture(
-      html`<gr-autocomplete no-debounce></gr-autocomplete>`
-    );
+    element = await fixture(html`<gr-autocomplete></gr-autocomplete>`);
   });
 
   test('renders', () => {
@@ -151,7 +153,10 @@
         ],
       }
     );
-    assert.equal(element.suggestionsDropdown?.errorMessage, 'blah not allowed');
+    assert.equal(
+      element.suggestionsDropdown?.queryStatus?.message,
+      'blah not allowed'
+    );
   });
 
   test('cursor starts on suggestions', async () => {
@@ -240,17 +245,21 @@
     await element.updateComplete;
 
     return assertFails(promise).then(async () => {
+      await element.latestSuggestionUpdateComplete;
       await waitUntil(() => !suggestionsEl().isHidden);
 
       const cancelHandler = sinon.spy();
       element.addEventListener('cancel', cancelHandler);
-      assert.equal(element.queryErrorMessage, 'Test error');
+      assert.deepEqual(element.queryStatus, {
+        type: AutocompleteQueryStatusType.ERROR,
+        message: 'Test error',
+      });
 
       pressKey(inputEl(), Key.ESC);
       await waitUntil(() => suggestionsEl().isHidden);
 
       assert.isFalse(cancelHandler.called);
-      assert.isUndefined(element.queryErrorMessage);
+      assert.isUndefined(element.queryStatus);
 
       pressKey(inputEl(), Key.ESC);
       await element.updateComplete;
@@ -260,16 +269,14 @@
   });
 
   test('emits commit and handles cursor movement', async () => {
-    let promise: Promise<AutocompleteSuggestion[]> = Promise.resolve([]);
-    const queryStub = sinon.spy(
-      (input: string) =>
-        (promise = Promise.resolve([
-          {name: input + ' 0', value: '0'},
-          {name: input + ' 1', value: '1'},
-          {name: input + ' 2', value: '2'},
-          {name: input + ' 3', value: '3'},
-          {name: input + ' 4', value: '4'},
-        ] as AutocompleteSuggestion[]))
+    const queryStub = sinon.spy((input: string) =>
+      Promise.resolve([
+        {name: input + ' 0', value: '0'},
+        {name: input + ' 1', value: '1'},
+        {name: input + ' 2', value: '2'},
+        {name: input + ' 3', value: '3'},
+        {name: input + ' 4', value: '4'},
+      ] as AutocompleteSuggestion[])
     );
     element.query = queryStub;
     await element.updateComplete;
@@ -280,7 +287,7 @@
     element.text = 'blah';
     await element.updateComplete;
 
-    return promise.then(async () => {
+    return element.latestSuggestionUpdateComplete!.then(async () => {
       await waitUntil(() => !suggestionsEl().isHidden);
 
       const commitHandler = sinon.spy();
@@ -456,24 +463,22 @@
   });
 
   test('suggestions should not carry over', async () => {
-    let promise: Promise<AutocompleteSuggestion[]> = Promise.resolve([]);
     const queryStub = sinon
       .stub()
-      .returns(
-        (promise = Promise.resolve([
-          {name: 'suggestion', value: '0'},
-        ] as AutocompleteSuggestion[]))
-      );
+      .resolves([{name: 'suggestion', value: '0'}] as AutocompleteSuggestion[]);
     element.query = queryStub;
     focusOnInput();
     element.text = 'bla';
     await element.updateComplete;
-    return promise.then(async () => {
+    return element.latestSuggestionUpdateComplete!.then(async () => {
       await waitUntil(() => element.suggestions.length > 0);
       assert.equal(element.suggestions.length, 1);
+
+      queryStub.resolves([] as AutocompleteSuggestion[]);
       element.text = '';
       element.threshold = 0;
       await element.updateComplete;
+      await element.latestSuggestionUpdateComplete;
       assert.equal(element.suggestions.length, 0);
     });
   });
@@ -488,11 +493,15 @@
     element.text = 'bla';
     await element.updateComplete;
     return assertFails(promise).then(async () => {
-      await waitUntil(() => element.queryErrorMessage === 'Test error');
+      await element.latestSuggestionUpdateComplete;
+      await waitUntil(() => element.queryStatus?.message === 'Test error');
+
+      queryStub.resolves([] as AutocompleteSuggestion[]);
       element.text = '';
       element.threshold = 0;
       await element.updateComplete;
-      assert.isUndefined(element.queryErrorMessage);
+      await element.latestSuggestionUpdateComplete;
+      assert.isUndefined(element.queryStatus);
     });
   });
 
@@ -514,6 +523,7 @@
     return promise.then(async () => {
       const commitHandler = sinon.spy();
       element.addEventListener('commit', commitHandler);
+      await element.latestSuggestionUpdateComplete;
       await waitUntil(() => element.suggestionsDropdown?.isHidden === false);
 
       pressKey(inputEl(), Key.ENTER);
@@ -524,15 +534,24 @@
   });
 
   test('tabComplete flag functions', async () => {
+    element.query = sinon
+      .stub()
+      .resolves([
+        {name: 'tunnel snakes rule!', value: 'snakes'},
+      ] as AutocompleteSuggestion[]);
+
     // commitHandler checks for the commit event, whereas commitSpy checks for
     // the _commit function of the element.
     const commitHandler = sinon.spy();
     element.addEventListener('commit', commitHandler);
     const commitSpy = sinon.spy(element, '_commit');
     element.setFocus(true);
-
-    element.suggestions = [{text: 'tunnel snakes rule!', name: ''}];
     element.tabComplete = false;
+    element.text = 'text1';
+    await element.updateComplete;
+
+    await element.latestSuggestionUpdateComplete;
+    await element.updateComplete;
     pressKey(inputEl(), Key.TAB);
     await element.updateComplete;
 
@@ -540,9 +559,12 @@
     assert.isFalse(commitSpy.called);
     assert.isFalse(element.focused);
 
-    element.tabComplete = true;
-    await element.updateComplete;
     element.setFocus(true);
+    element.tabComplete = true;
+    element.text = 'text2';
+    await element.updateComplete;
+
+    await element.latestSuggestionUpdateComplete;
     await element.updateComplete;
     pressKey(inputEl(), Key.TAB);
 
@@ -597,7 +619,11 @@
       ' allowNonSuggestedValues',
     () => {
       const commitStub = sinon.stub(element, '_commit');
-      element.queryErrorMessage = 'Error';
+      element.queryStatus = {
+        type: AutocompleteQueryStatusType.ERROR,
+        message: 'Error',
+      };
+      element.suggestions = [];
       element.handleInputCommit();
       assert.isFalse(commitStub.called);
     }
@@ -620,7 +646,11 @@
     () => {
       const commitStub = sinon.stub(element, '_commit');
       element.allowNonSuggestedValues = true;
-      element.queryErrorMessage = 'Error';
+      element.queryStatus = {
+        type: AutocompleteQueryStatusType.ERROR,
+        message: 'Error',
+      };
+      element.suggestions = [];
       element.handleInputCommit();
       assert.isTrue(commitStub.called);
     }
@@ -629,6 +659,7 @@
   test('handleInputCommit with autocomplete open calls commit', () => {
     const commitStub = sinon.stub(element, '_commit');
     suggestionsEl().isHidden = false;
+    element.suggestions = [{name: 'first suggestion'}];
     element.handleInputCommit();
     assert.isTrue(commitStub.calledOnce);
   });
@@ -671,6 +702,215 @@
     assert.equal(element.text, 'file:x');
   });
 
+  test('render loading replace with suggestions when done', async () => {
+    const queryPromise = mockPromise<AutocompleteSuggestion[]>();
+    element.query = (_: string) => queryPromise;
+
+    element.setFocus(true);
+    element.text = 'blah';
+    await element.updateComplete;
+    await waitUntil(() => !suggestionsEl().isHidden);
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading...',
+    });
+
+    queryPromise.resolve([{name: 'suggestion 1'}] as AutocompleteSuggestion[]);
+    await element.latestSuggestionUpdateComplete;
+    await element.updateComplete;
+
+    assert.equal(element.suggestions.length, 1);
+    assert.isUndefined(element.queryStatus);
+  });
+
+  test('render loading replace with error when done', async () => {
+    const queryPromise = mockPromise<AutocompleteSuggestion[]>();
+    element.query = (_: string) => queryPromise;
+
+    element.setFocus(true);
+    element.text = 'blah';
+    await element.updateComplete;
+    await waitUntil(() => !suggestionsEl().isHidden);
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading...',
+    });
+
+    queryPromise.reject(new Error('Test error'));
+    await assertFails(queryPromise);
+    await element.latestSuggestionUpdateComplete;
+    await element.updateComplete;
+
+    assert.equal(element.suggestions.length, 0);
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.ERROR,
+      message: 'Test error',
+    });
+  });
+
+  test('render loading esc cancels', async () => {
+    const queryPromise = mockPromise<AutocompleteSuggestion[]>();
+    element.query = (_: string) => queryPromise;
+
+    element.setFocus(true);
+    element.text = 'blah';
+    await element.updateComplete;
+    await waitUntil(() => !suggestionsEl().isHidden);
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading...',
+    });
+
+    const cancelHandler = sinon.spy();
+    element.addEventListener('cancel', cancelHandler);
+    pressKey(inputEl(), Key.ESC);
+    await waitUntil(() => suggestionsEl().isHidden);
+
+    assert.isFalse(cancelHandler.called);
+    assert.isUndefined(element.queryStatus);
+
+    pressKey(inputEl(), Key.ESC);
+    await element.updateComplete;
+
+    assert.isTrue(cancelHandler.called);
+  });
+
+  test('while loading queue enter commits', async () => {
+    const commitHandler = sinon.stub();
+    element.addEventListener('commit', commitHandler);
+    let resolvePromise: (value: AutocompleteSuggestion[]) => void;
+    const blockingPromise = new Promise<AutocompleteSuggestion[]>(resolve => {
+      resolvePromise = resolve;
+    });
+    element.query = (_: string) => blockingPromise;
+
+    element.setFocus(true);
+    element.text = 'blah';
+    await element.updateComplete;
+    await waitUntil(() => !suggestionsEl().isHidden);
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading...',
+    });
+
+    pressKey(inputEl(), Key.ENTER);
+    await element.updateComplete;
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading... (Handle Enter on load)',
+    });
+
+    resolvePromise!([{name: 'suggestion 1'}] as AutocompleteSuggestion[]);
+    await element.latestSuggestionUpdateComplete;
+    await element.updateComplete;
+
+    assert.equal(element.suggestions.length, 0);
+    assert.isUndefined(element.queryStatus);
+    assert.isTrue(commitHandler.called);
+  });
+
+  test('while loading queue tab completes', async () => {
+    element.tabComplete = true;
+    const commitHandler = sinon.stub();
+    element.addEventListener('commit', commitHandler);
+    const queryPromise = mockPromise<AutocompleteSuggestion[]>();
+    element.query = (_: string) => queryPromise;
+
+    element.setFocus(true);
+    element.text = 'blah';
+    await element.updateComplete;
+    await waitUntil(() => !suggestionsEl().isHidden);
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading...',
+    });
+
+    pressKey(inputEl(), Key.TAB);
+    await element.updateComplete;
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading... (Handle Tab on load)',
+    });
+
+    queryPromise.resolve([{name: 'suggestion 1'}] as AutocompleteSuggestion[]);
+    await element.latestSuggestionUpdateComplete;
+    await element.updateComplete;
+
+    assert.equal(element.suggestions.length, 0);
+    assert.isUndefined(element.queryStatus);
+    assert.isFalse(commitHandler.called);
+    assert.equal(element.text, 'suggestion 1');
+  });
+
+  test('while loading and queued update text cancels', async () => {
+    const commitHandler = sinon.stub();
+    element.addEventListener('commit', commitHandler);
+    const queryPromise = mockPromise<AutocompleteSuggestion[]>();
+    element.query = (_: string) => queryPromise;
+
+    element.setFocus(true);
+    element.text = 'blah';
+    await element.updateComplete;
+    await waitUntil(() => !suggestionsEl().isHidden);
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading...',
+    });
+
+    pressKey(inputEl(), Key.ENTER);
+    await element.updateComplete;
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading... (Handle Enter on load)',
+    });
+
+    element.text = 'more blah';
+    await element.updateComplete;
+
+    queryPromise.resolve([{name: 'suggestion 1'}] as AutocompleteSuggestion[]);
+    await element.latestSuggestionUpdateComplete;
+    await element.updateComplete;
+
+    // Commit for stale request is not called.
+    assert.isFalse(commitHandler.called);
+  });
+
+  test('while loading and queued esc cancels', async () => {
+    const commitHandler = sinon.stub();
+    element.addEventListener('commit', commitHandler);
+    const queryPromise = mockPromise<AutocompleteSuggestion[]>();
+    element.query = (_: string) => queryPromise;
+
+    element.setFocus(true);
+    element.text = 'blah';
+    await element.updateComplete;
+    await waitUntil(() => !suggestionsEl().isHidden);
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading...',
+    });
+
+    pressKey(inputEl(), Key.ENTER);
+    await element.updateComplete;
+    assert.deepEqual(element.queryStatus, {
+      type: AutocompleteQueryStatusType.LOADING,
+      message: 'Loading... (Handle Enter on load)',
+    });
+
+    pressKey(inputEl(), Key.ESC);
+    await element.updateComplete;
+
+    queryPromise.resolve([{name: 'suggestion 1'}] as AutocompleteSuggestion[]);
+    await element.latestSuggestionUpdateComplete;
+    await element.updateComplete;
+
+    // Commit for stale request is not called.
+    assert.isFalse(commitHandler.called);
+    // Query results and status are cleared
+    assert.equal(element.suggestions.length, 0);
+    assert.isUndefined(element.queryStatus);
+  });
+
   suite('focus', () => {
     let commitSpy: sinon.SinonSpy;
     let focusSpy: sinon.SinonSpy;
@@ -688,13 +928,16 @@
       await element.updateComplete;
 
       assert.equal(element.suggestions.length, 0);
-      assert.isUndefined(element.queryErrorMessage);
+      assert.isUndefined(element.queryStatus);
       assert.isTrue(suggestionsEl().isHidden);
     });
 
     test('enter in input does not re-render error', async () => {
       element.allowNonSuggestedValues = true;
-      element.queryErrorMessage = 'Error message';
+      element.queryStatus = {
+        type: AutocompleteQueryStatusType.ERROR,
+        message: 'Error message',
+      };
 
       pressKey(inputEl(), Key.ENTER);
 
@@ -702,7 +945,7 @@
       await element.updateComplete;
 
       assert.equal(element.suggestions.length, 0);
-      assert.isUndefined(element.queryErrorMessage);
+      assert.isUndefined(element.queryStatus);
       assert.isTrue(suggestionsEl().isHidden);
     });
 
diff --git a/polygerrit-ui/app/elements/shared/gr-change-status/gr-change-status.ts b/polygerrit-ui/app/elements/shared/gr-change-status/gr-change-status.ts
index d2b9e2d..073d9f1 100644
--- a/polygerrit-ui/app/elements/shared/gr-change-status/gr-change-status.ts
+++ b/polygerrit-ui/app/elements/shared/gr-change-status/gr-change-status.ts
@@ -7,7 +7,6 @@
 import '../gr-tooltip-content/gr-tooltip-content';
 import '../../../styles/shared-styles';
 import {ChangeInfo} from '../../../types/common';
-import {ParsedChangeInfo} from '../../../types/types';
 import {sharedStyles} from '../../../styles/shared-styles';
 import {LitElement, PropertyValues, html, css} from 'lit';
 import {customElement, property, state} from 'lit/decorators.js';
@@ -50,9 +49,6 @@
   @property({type: Boolean, reflect: true})
   flat = false;
 
-  @property({type: Object})
-  change?: ChangeInfo | ParsedChangeInfo;
-
   @property({type: String})
   status?: ChangeStates;
 
diff --git a/polygerrit-ui/app/elements/shared/gr-editable-label/gr-editable-label_test.ts b/polygerrit-ui/app/elements/shared/gr-editable-label/gr-editable-label_test.ts
index d916118..3bb058e 100644
--- a/polygerrit-ui/app/elements/shared/gr-editable-label/gr-editable-label_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-editable-label/gr-editable-label_test.ts
@@ -295,7 +295,10 @@
       suggestions = [{name: 'value text 1'}, {name: 'value text 2'}];
       await element.open();
 
+      // Waiting until dropdown not hidden, will ensure dialog is open and input
+      // is focused, but not that the suggestion has loaded.
       await waitUntil(() => !autocomplete.suggestionsDropdown!.isHidden);
+      await autocomplete.latestSuggestionUpdateComplete;
 
       pressKey(autocomplete.input!, Key.ENTER);
 
@@ -312,7 +315,11 @@
     test('autocomplete suggestions closed enter saves suggestion', async () => {
       suggestions = [{name: 'value text 1'}, {name: 'value text 2'}];
       await element.open();
+      // Waiting until dropdown not hidden, will ensure dialog is open and input
+      // is focused, but not that the suggestion has loaded.
       await waitUntil(() => !autocomplete.suggestionsDropdown!.isHidden);
+      await autocomplete.latestSuggestionUpdateComplete;
+
       // Press enter to close suggestions.
       pressKey(autocomplete.input!, Key.ENTER);
 
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-row.ts b/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-row.ts
index 13a6b00..b97ae59 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-row.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-row.ts
@@ -160,6 +160,8 @@
         ${this.renderLineNumberCell(Side.RIGHT)}
         ${this.renderSignCell(Side.RIGHT)} ${this.renderContentCell(Side.RIGHT)}
       </tr>
+      ${this.renderPostLineSlot(Side.LEFT)}
+      ${this.renderPostLineSlot(Side.RIGHT)}
     `;
     if (this.addTableWrapperForTesting) {
       return html`<table>
@@ -456,6 +458,13 @@
         id=${this.contentId(side)}
       >${textElement}</div>`;
   }
+
+  private renderPostLineSlot(side: Side) {
+    const lineNumber = this.lineNumber(side);
+    return lineNumber && Number.isInteger(lineNumber)
+      ? html`<slot name="post-${side}-line-${lineNumber}"></slot>`
+      : nothing;
+  }
 }
 
 declare global {
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-row_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-row_test.ts
index 1c7b311..42d30aa 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-row_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-row_test.ts
@@ -87,6 +87,8 @@
                 </div>
               </td>
             </tr>
+            <slot name="post-left-line-1"></slot>
+            <slot name="post-right-line-1"></slot>
           </tbody>
         </table>
       `
@@ -147,6 +149,8 @@
                 </div>
               </td>
             </tr>
+            <slot name="post-left-line-1"></slot>
+            <slot name="post-right-line-1"></slot>
           </tbody>
         </table>
       `
@@ -201,6 +205,7 @@
                   <slot name="right-1"> </slot>
                 </div>
               </td>
+              <slot name="post-right-line-1"></slot>
             </tr>
           </tbody>
         </table>
@@ -257,6 +262,7 @@
                 <div class="contentText gr-diff" data-side="right"></div>
               </td>
             </tr>
+            <slot name="post-left-line-1"></slot>
           </tbody>
         </table>
       `
diff --git a/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-section_test.ts b/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-section_test.ts
index 14f4536..381f9b2 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-section_test.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff-builder/gr-diff-section_test.ts
@@ -126,8 +126,14 @@
       element,
       /* HTML */ `
         <gr-diff-row class="left-1 right-1"> </gr-diff-row>
+        <slot name="post-left-line-1"></slot>
+        <slot name="post-right-line-1"></slot>
         <gr-diff-row class="left-1 right-1"> </gr-diff-row>
+        <slot name="post-left-line-1"></slot>
+        <slot name="post-right-line-1"></slot>
         <gr-diff-row class="left-1 right-1"> </gr-diff-row>
+        <slot name="post-left-line-1"></slot>
+        <slot name="post-right-line-1"></slot>
         <table>
           <tbody class="both gr-diff section">
             <tr
diff --git a/polygerrit-ui/app/models/accounts-model/accounts-model.ts b/polygerrit-ui/app/models/accounts-model/accounts-model.ts
index 2bf6068..1c67857 100644
--- a/polygerrit-ui/app/models/accounts-model/accounts-model.ts
+++ b/polygerrit-ui/app/models/accounts-model/accounts-model.ts
@@ -8,11 +8,14 @@
 import {RestApiService} from '../../services/gr-rest-api/gr-rest-api';
 import {UserId} from '../../types/common';
 import {getUserId, isDetailedAccount} from '../../utils/account-util';
+import {hasOwnProperty} from '../../utils/common-util';
 import {define} from '../dependency';
 import {Model} from '../model';
 
 export interface AccountsState {
-  accounts: {[id: UserId]: AccountDetailInfo};
+  accounts: {
+    [id: UserId]: AccountDetailInfo | AccountInfo;
+  };
 }
 
 export const accountsModelToken = define<AccountsModel>('accounts-model');
@@ -24,33 +27,36 @@
     });
   }
 
-  private updateStateAccount(id: UserId, account?: AccountDetailInfo) {
+  private updateStateAccount(
+    id: UserId,
+    account: AccountDetailInfo | AccountInfo
+  ) {
     if (!account) return;
     const current = {...this.getState()};
     current.accounts = {...current.accounts, [id]: account};
     this.setState(current);
   }
 
-  async getAccount(partialAccount: AccountInfo) {
+  async getAccount(
+    partialAccount: AccountInfo
+  ): Promise<AccountDetailInfo | AccountInfo> {
     const current = this.getState();
     const id = getUserId(partialAccount);
-    if (current.accounts[id]) return current.accounts[id];
+    if (hasOwnProperty(current.accounts, id)) return current.accounts[id];
     // It is possible to add emails to CC when they don't have a Gerrit
-    // account. In this case getAccountDetails will return a 404 error hence
-    // pass an empty error function to handle that.
+    // account. In this case getAccountDetails will return a 404 error then
+    // we at least use what is in partialAccount.
     const account = await this.restApiService.getAccountDetails(id, () => {
-      this.updateStateAccount(id, partialAccount as AccountDetailInfo);
+      this.updateStateAccount(id, partialAccount);
       return;
     });
     if (account) this.updateStateAccount(id, account);
-    return account;
+    return account ?? partialAccount;
   }
 
   async fillDetails(account: AccountInfo) {
     if (!isDetailedAccount(account)) {
-      if (account.email) return await this.getAccount({email: account.email});
-      else if (account._account_id)
-        return await this.getAccount({_account_id: account._account_id});
+      return await this.getAccount(account);
     }
     return account;
   }
diff --git a/polygerrit-ui/app/services/flags/flags.ts b/polygerrit-ui/app/services/flags/flags.ts
index 29e9259..7488e79 100644
--- a/polygerrit-ui/app/services/flags/flags.ts
+++ b/polygerrit-ui/app/services/flags/flags.ts
@@ -19,5 +19,4 @@
   PUSH_NOTIFICATIONS_DEVELOPER = 'UiFeature__push_notifications_developer',
   PUSH_NOTIFICATIONS = 'UiFeature__push_notifications',
   SUGGEST_EDIT = 'UiFeature__suggest_edit',
-  REBASE_CHAIN = 'UiFeature__rebase_chain',
 }
diff --git a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl.ts b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl.ts
index 0d0c88f..610d8f3 100644
--- a/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl.ts
+++ b/polygerrit-ui/app/services/gr-rest-api/gr-rest-api-impl.ts
@@ -769,7 +769,7 @@
     userId: AccountId | EmailAddress,
     errFn?: ErrorCallback
   ): Promise<AccountDetailInfo | undefined> {
-    return this._restApiHelper.fetchJSON({
+    return this._fetchSharedCacheURL({
       url: `/accounts/${encodeURIComponent(userId)}/detail`,
       anonymizedUrl: '/accounts/*/detail',
       errFn,
diff --git a/polygerrit-ui/app/utils/async-util.ts b/polygerrit-ui/app/utils/async-util.ts
index 752de62..905b16c 100644
--- a/polygerrit-ui/app/utils/async-util.ts
+++ b/polygerrit-ui/app/utils/async-util.ts
@@ -62,6 +62,8 @@
   /**
    * Promise that is resolved after the callback is run or the task is
    * cancelled.
+   *
+   * If callback returns a Promise this resolves after the promise is settled.
    */
   public readonly promise: Promise<ResolvedDelayedTaskStatus>;
 
@@ -69,14 +71,25 @@
     value: ResolvedDelayedTaskStatus | PromiseLike<ResolvedDelayedTaskStatus>
   ) => void;
 
-  constructor(private callback: () => void, waitMs = 0) {
+  private callCallbackAndResolveOnCompletion() {
+    let callbackResult;
+    if (this.callback) callbackResult = this.callback();
+    if (callbackResult instanceof Promise) {
+      callbackResult.finally(() =>
+        this.resolvePromise!(ResolvedDelayedTaskStatus.CALLBACK_EXECUTED)
+      );
+    } else {
+      this.resolvePromise!(ResolvedDelayedTaskStatus.CALLBACK_EXECUTED);
+    }
+  }
+
+  constructor(private callback: () => void | Promise<void>, waitMs = 0) {
     this.promise = new Promise(resolve => {
       this.resolvePromise = resolve;
       this.timerId = window.setTimeout(() => {
         if (this.timerId) _testOnly_allTasks.delete(this.timerId);
         this.timerId = undefined;
-        if (this.callback) this.callback();
-        resolve(ResolvedDelayedTaskStatus.CALLBACK_EXECUTED);
+        this.callCallbackAndResolveOnCompletion();
       }, waitMs);
       _testOnly_allTasks.set(this.timerId, this);
     });
@@ -98,8 +111,7 @@
   flush() {
     if (this.isActive()) {
       this.cancelTimer();
-      if (this.callback) this.callback();
-      this.resolvePromise?.(ResolvedDelayedTaskStatus.CALLBACK_EXECUTED);
+      this.callCallbackAndResolveOnCompletion();
     }
   }
 
diff --git a/polygerrit-ui/app/utils/async-util_test.ts b/polygerrit-ui/app/utils/async-util_test.ts
index 9f029b8..ee4f73a 100644
--- a/polygerrit-ui/app/utils/async-util_test.ts
+++ b/polygerrit-ui/app/utils/async-util_test.ts
@@ -6,8 +6,8 @@
 import {assert} from '@open-wc/testing';
 import {SinonFakeTimers} from 'sinon';
 import '../test/common-test-setup';
-import {waitEventLoop} from '../test/test-utils';
-import {asyncForeach, debounceP} from './async-util';
+import {mockPromise, waitEventLoop, waitUntil} from '../test/test-utils';
+import {asyncForeach, debounceP, DelayedTask} from './async-util';
 
 suite('async-util tests', () => {
   suite('asyncForeach', () => {
@@ -205,4 +205,16 @@
       await waitEventLoop();
     });
   });
+
+  test('DelayedTask promise resolved when callback is done', async () => {
+    const callbackPromise = mockPromise<void>();
+    const task = new DelayedTask(() => callbackPromise);
+    let completed = false;
+    task.promise.then(() => (completed = true));
+    await waitUntil(() => !task.isActive());
+
+    assert.isFalse(completed);
+    callbackPromise.resolve();
+    await waitUntil(() => completed);
+  });
 });