Make implicit reviewers feature actually work on GWT UI

This was presumably fixed in Ia5e6b9791 and in I8b735db4f. It turns
out, that labels map is not null in GWT UI, as it is the case in PG,
but also non empty, even in non-voting case: Code-Review: 0.

Fix the optimization check to account for zero votes.

Bug: Issue 4638
Change-Id: I6d9a2cc42ec51e6b1df13b96cf4bcdd082c87f60

WORKSPACE

@@ -696,12 +696,20 @@ maven_jar(
     sha1 = "42a25dc3219429f0e5d060061f71acb49bf010a0",
 )
 
+TRUTH_VERS = "0.31"
+
 maven_jar(
     name = "truth",
-    artifact = "com.google.truth:truth:0.31",
+    artifact = "com.google.truth:truth:" + TRUTH_VERS,
     sha1 = "1a926b0cb2879fd32efbb3716ee8bab040f4218b",
 )
 
+maven_jar(
+    name = "truth-java8-extension",
+    artifact = "com.google.truth.extensions:truth-java8-extension:" + TRUTH_VERS,
+    sha1 = "a7e80e631f2bf4ecc2b99ad1e33059eb0dcc6ea0",
+)
+
 maven_jar(
     name = "easymock",
     artifact = "org.easymock:easymock:3.1",  # When bumping the version

gerrit-acceptance-framework/BUILD

@@ -41,6 +41,7 @@ java_library2(
         "//gerrit-server:testutil",
         "//gerrit-server/src/main/prolog:common",
         "//lib:truth",
+        "//lib:truth-java8-extension",
         "//lib/auto:auto-value",
         "//lib/httpcomponents:fluent-hc",
         "//lib/httpcomponents:httpclient",

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/change/ChangeIT.java

@@ -15,6 +15,7 @@
 package com.google.gerrit.acceptance.api.change;
 
 import static com.google.common.truth.Truth.assertThat;
+import static com.google.common.truth.Truth8.assertThat;
 import static com.google.common.truth.TruthJUnit.assume;
 import static com.google.gerrit.acceptance.GitUtil.assertPushOk;
 import static com.google.gerrit.acceptance.GitUtil.pushHead;
@@ -31,9 +32,11 @@ import static com.google.gerrit.server.project.Util.category;
 import static com.google.gerrit.server.project.Util.value;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static java.util.stream.Collectors.toList;
+import static java.util.stream.Collectors.toSet;
 import static org.junit.Assert.fail;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
@@ -57,6 +60,7 @@ import com.google.gerrit.extensions.api.changes.NotifyInfo;
 import com.google.gerrit.extensions.api.changes.RebaseInput;
 import com.google.gerrit.extensions.api.changes.RecipientType;
 import com.google.gerrit.extensions.api.changes.ReviewInput;
+import com.google.gerrit.extensions.api.changes.ReviewInput.DraftHandling;
 import com.google.gerrit.extensions.api.changes.RevisionApi;
 import com.google.gerrit.extensions.api.projects.BranchInput;
 import com.google.gerrit.extensions.client.ChangeKind;
@@ -114,6 +118,8 @@ import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
 import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
 import org.eclipse.jgit.junit.TestRepository;
 import org.eclipse.jgit.lib.Constants;
@@ -945,17 +951,41 @@ public class ChangeIT extends AbstractDaemonTest {
   }
 
   @Test
-  public void implicitlyCcOnNonVotingReview() throws Exception {
+  public void implicitlyCcOnNonVotingReviewPgStyle() throws Exception {
     PushOneCommit.Result r = createChange();
     setApiUser(user);
-    gApi.changes().id(r.getChangeId()).revision(r.getCommit().name()).review(new ReviewInput());
+    assertThat(getReviewerState(r.getChangeId(), user.id)).isEmpty();
 
-    ChangeInfo c = gApi.changes().id(r.getChangeId()).get();
-    // If we're not reading from NoteDb, then the CCed user will be returned
-    // in the REVIEWER state.
-    ReviewerState state = notesMigration.readChanges() ? CC : REVIEWER;
-    assertThat(c.reviewers.get(state).stream().map(ai -> ai._accountId).collect(toList()))
-        .containsExactly(user.id.get());
+    // Exact request format made by PG UI at ddc6b7160fe416fed9e7e3180489d44c82fd64f8.
+    ReviewInput in = new ReviewInput();
+    in.drafts = DraftHandling.PUBLISH_ALL_REVISIONS;
+    in.labels = ImmutableMap.of();
+    in.message = "comment";
+    in.reviewers = ImmutableList.of();
+    gApi.changes().id(r.getChangeId()).revision(r.getCommit().name()).review(in);
+
+    // If we're not reading from NoteDb, then the CCed user will be returned in the REVIEWER state.
+    assertThat(getReviewerState(r.getChangeId(), user.id))
+        .hasValue(notesMigration.readChanges() ? CC : REVIEWER);
+  }
+
+  @Test
+  public void implicitlyCcOnNonVotingReviewGwtStyle() throws Exception {
+    PushOneCommit.Result r = createChange();
+    setApiUser(user);
+    assertThat(getReviewerState(r.getChangeId(), user.id)).isEmpty();
+
+    // Exact request format made by GWT UI at ddc6b7160fe416fed9e7e3180489d44c82fd64f8.
+    ReviewInput in = new ReviewInput();
+    in.labels = ImmutableMap.of("Code-Review", (short) 0);
+    in.strictLabels = true;
+    in.drafts = DraftHandling.PUBLISH_ALL_REVISIONS;
+    in.message = "comment";
+    gApi.changes().id(r.getChangeId()).revision(r.getCommit().name()).review(in);
+
+    // If we're not reading from NoteDb, then the CCed user will be returned in the REVIEWER state.
+    assertThat(getReviewerState(r.getChangeId(), user.id))
+        .hasValue(notesMigration.readChanges() ? CC : REVIEWER);
   }
 
   @Test
@@ -2290,6 +2320,20 @@ public class ChangeIT extends AbstractDaemonTest {
     return changeResourceFactory.create(ctls.get(0));
   }
 
+  private Optional<ReviewerState> getReviewerState(String changeId, Account.Id accountId)
+      throws Exception {
+    ChangeInfo c = gApi.changes().id(changeId).get(EnumSet.of(ListChangesOption.DETAILED_LABELS));
+    Set<ReviewerState> states =
+        c.reviewers
+            .entrySet()
+            .stream()
+            .filter(e -> e.getValue().stream().anyMatch(a -> a._accountId == accountId.get()))
+            .map(e -> e.getKey())
+            .collect(toSet());
+    assertThat(states.size()).named(states.toString()).isAtMost(1);
+    return states.stream().findFirst();
+  }
+
   private void setChangeStatus(Change.Id id, Change.Status newStatus) throws Exception {
     try (BatchUpdate batchUpdate =
         updateFactory.create(db, project, atrScope.get().getUser(), TimeUtil.nowTs())) {

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

@@ -244,7 +244,10 @@ public class PostReview implements RestModifyView<RevisionResource, ReviewInput>
         batchUpdateFactory.create(
             db.get(), revision.getChange().getProject(), revision.getUser(), ts)) {
       Account.Id id = bu.getUser().getAccountId();
-      boolean ccOrReviewer = input.labels != null && !input.labels.isEmpty();
+      boolean ccOrReviewer = false;
+      if (input.labels != null && !input.labels.isEmpty()) {
+        ccOrReviewer = input.labels.values().stream().filter(v -> v != 0).findFirst().isPresent();
+      }
 
       if (!ccOrReviewer) {
         // Check if user was already CCed or reviewing prior to this review.

lib/BUILD

@@ -230,6 +230,17 @@ java_library(
     ],
 )
 
+java_library(
+    name = "truth-java8-extension",
+    data = ["//lib:LICENSE-DO_NOT_DISTRIBUTE"],
+    visibility = ["//visibility:public"],
+    exports = [
+        ":guava",
+        ":truth",
+        "@truth-java8-extension//jar",
+    ],
+)
+
 java_library(
     name = "javassist",
     data = ["//lib:LICENSE-DO_NOT_DISTRIBUTE"],