Don't add reviewers to merged changes

If a change goes directly from WIP to MERGED due to the push of a
WIP change (e.g.)
1. Upload a change with %wip.
2. Push the commit, thus closing the change automatically.

Reviewers are added and put in Attention-Set, because the change goes
public as soon as it is merged. Now they have notifications to act on a
change that is merged.

To avoid this, simply don't automatically add reviewers to merged
changes.

Change-Id: I8eb03a0507624a4e09f837e59eb764e8e6548c69

src/main/java/com/googlesource/gerrit/plugins/reviewers/Reviewers.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/reviewers/Reviewers.java b/src/main/java/com/googlesource/gerrit/plugins/reviewers/Reviewers.java
index 188cb77..bdbee0e 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/reviewers/Reviewers.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/reviewers/Reviewers.java
@@ -14,6 +14,8 @@
 
 package com.googlesource.gerrit.plugins.reviewers;
 
+import static com.google.gerrit.extensions.client.ChangeStatus.MERGED;
+
 import com.google.common.flogger.FluentLogger;
 import com.google.gerrit.entities.Change;
 import com.google.gerrit.entities.Project;
@@ -96,6 +98,9 @@
     if (config.ignoreWip() && Boolean.TRUE.equals(c.workInProgress)) {
       return;
     }
+    if (c.status.equals(MERGED)) {
+      return;
+    }
     Project.NameKey projectName = Project.nameKey(c.project);
 
     List<ReviewerFilter> filters = getFilters(projectName);

src/test/java/com/googlesource/gerrit/plugins/reviewers/ReviewersIT.java

diff --git a/src/test/java/com/googlesource/gerrit/plugins/reviewers/ReviewersIT.java b/src/test/java/com/googlesource/gerrit/plugins/reviewers/ReviewersIT.java
index bedd4de..6e4df58 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/reviewers/ReviewersIT.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/reviewers/ReviewersIT.java
@@ -104,7 +104,7 @@
   }
 
   @Test
-  public void privateBitFlippedAndReviewersAddedOnSubmit() throws Exception {
+  public void reviewersNotAddedOnSubmitOfPrivateChange() throws Exception {
     createFilters(filter("*").reviewer(user));
     PushOneCommit.Result r = createChange("refs/for/master%private");
     assertThat(r.getChange().change().isPrivate()).isTrue();
@@ -113,14 +113,29 @@
     // This adds admin as reviewer
     gApi.changes().id(changeId).current().review(ReviewInput.approve());
     gApi.changes().id(changeId).current().submit();
-    assertThat(reviewersFor(changeId))
-        .containsExactlyElementsIn(ImmutableSet.of(admin.id(), user.id()));
+    assertThat(reviewersFor(changeId)).containsExactlyElementsIn(ImmutableSet.of(admin.id()));
     ChangeInfo info = gApi.changes().id(changeId).get();
     assertThat(info.status).isEqualTo(ChangeStatus.MERGED);
     assertThat(info.isPrivate).isNull();
   }
 
   @Test
+  public void reviewersNotAddedOnPushOfWIPChange() throws Exception {
+    createFilters(filter("*").reviewer(user));
+    PushOneCommit.Result r = createChange("refs/for/master%wip");
+    assertThat(r.getChange().change().isWorkInProgress()).isTrue();
+    String changeId = r.getChangeId();
+    assertNoReviewersAddedFor(changeId);
+    // This adds admin as reviewer
+    gApi.changes().id(changeId).current().review(ReviewInput.approve());
+    pushToHeads("refs/heads/master", changeId);
+    assertThat(reviewersFor(changeId)).containsExactlyElementsIn(ImmutableSet.of(admin.id()));
+    ChangeInfo info = gApi.changes().id(changeId).get();
+    assertThat(info.status).isEqualTo(ChangeStatus.MERGED);
+    assertThat(info.workInProgress).isNull();
+  }
+
+  @Test
   public void reviewerAddedOnPrivateBitFlip() throws Exception {
     createFilters(filter("*").reviewer(user));
     PushOneCommit.Result r = createChange("refs/for/master%private");
@@ -203,4 +218,9 @@
     assertThat(gApi.changes().id(changeId).get().reviewers.get(REVIEWER)).isNull();
     assertThat(gApi.changes().id(changeId).get().reviewers.get(CC)).isNull();
   }
+
+  private PushOneCommit.Result pushToHeads(String ref, String changeId) throws Exception {
+    PushOneCommit push = pushFactory.create(admin.newIdent(), testRepo, changeId);
+    return push.to(ref);
+  }
 }