Include submitter in ChangeInfo

Somewhat surprisingly, this was never directly exposed by the REST API.
We already look up the whole PatchSetApproval record corresponding to
submission in order to set `submitted`, so it's trivial to add the
account info as well.

Change-Id: I9bb9cb2c0e85f26548fc94154dd2e02fb4b9537b

Documentation/rest-api-changes.txt

@@ -5642,6 +5642,9 @@ updated.
 |`submitted`          |only set for merged changes|
 The link:rest-api.html#timestamp[timestamp] of when the change was
 submitted.
+|`submitter`          |only set for merged changes|
+The user who submitted the change, as an
+link:rest-api-accounts.html#account-info[ AccountInfo] entity.
 |`starred`            |not set if `false`|
 Whether the calling user has starred this change with the default label.
 |`stars`              |optional|

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

@@ -2117,10 +2117,19 @@ public class ChangeIT extends AbstractDaemonTest {
   @Test
   public void submitted() throws Exception {
     PushOneCommit.Result r = createChange();
-    gApi.changes().id(r.getChangeId()).revision(r.getCommit().name()).review(ReviewInput.approve());
-    assertThat(gApi.changes().id(r.getChangeId()).info().submitted).isNull();
-    gApi.changes().id(r.getChangeId()).revision(r.getCommit().name()).submit();
-    assertThat(gApi.changes().id(r.getChangeId()).info().submitted).isNotNull();
+    String id = r.getChangeId();
+
+    ChangeInfo c = gApi.changes().id(r.getChangeId()).info();
+    assertThat(c.submitted).isNull();
+    assertThat(c.submitter).isNull();
+
+    gApi.changes().id(id).current().review(ReviewInput.approve());
+    gApi.changes().id(id).current().submit();
+
+    c = gApi.changes().id(r.getChangeId()).info();
+    assertThat(c.submitted).isNotNull();
+    assertThat(c.submitter).isNotNull();
+    assertThat(c.submitter._accountId).isEqualTo(atrScope.get().getUser().getAccountId().get());
   }
 
   @Test

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/change/CreateChangeIT.java

@@ -401,6 +401,7 @@ public class CreateChangeIT extends AbstractDaemonTest {
     assertThat(out.workInProgress).isEqualTo(in.workInProgress);
     assertThat(out.revisions).hasSize(1);
     assertThat(out.submitted).isNull();
+    assertThat(out.submitter).isNull();
     Boolean draft = Iterables.getOnlyElement(out.revisions.values()).draft;
     assertThat(booleanToDraftStatus(draft)).isEqualTo(in.status);
     return out;

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/common/ChangeInfo.java

@@ -35,6 +35,7 @@ public class ChangeInfo {
   public Timestamp created;
   public Timestamp updated;
   public Timestamp submitted;
+  public AccountInfo submitter;
   public Boolean starred;
   public Boolean muted;
   public Collection<String> stars;

gerrit-gwtui-common/src/main/java/com/google/gerrit/client/info/ChangeInfo.java

@@ -134,6 +134,8 @@ public class ChangeInfo extends JavaScriptObject {
 
   private native String submittedRaw() /*-{ return this.submitted; }-*/;
 
+  public final native AccountInfo submitter() /*-{ return this.submitter; }-*/;
+
   public final native boolean starred() /*-{ return this.starred ? true : false; }-*/;
 
   public final native boolean muted() /*-{ return this.muted ? true : false; }-*/;

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

@@ -133,6 +133,7 @@ public class ActionJson {
     copy.starred = changeInfo.starred;
     copy.stars = changeInfo.stars;
     copy.submitted = changeInfo.submitted;
+    copy.submitter = changeInfo.submitter;
     copy.id = changeInfo.id;
     return copy;
   }

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

@@ -556,7 +556,7 @@ public class ChangeJson {
       out.removableReviewers = removableReviewers(ctl, out);
     }
 
-    out.submitted = getSubmittedOn(cd);
+    setSubmitter(cd, out);
     out.plugins =
         pluginDefinedAttributesFactory != null ? pluginDefinedAttributesFactory.create(cd) : null;
     out.revertOf = cd.change().getRevertOf() != null ? cd.change().getRevertOf().get() : null;
@@ -852,9 +852,13 @@ public class ChangeJson {
     return Ints.tryParse(value);
   }
 
-  private Timestamp getSubmittedOn(ChangeData cd) throws OrmException {
+  private void setSubmitter(ChangeData cd, ChangeInfo out) throws OrmException {
     Optional<PatchSetApproval> s = cd.getSubmitApproval();
-    return s.isPresent() ? s.get().getGranted() : null;
+    if (!s.isPresent()) {
+      return;
+    }
+    out.submitted = s.get().getGranted();
+    out.submitter = accountLoader.get(s.get().getAccountId());
   }
 
   private Map<String, LabelWithStatus> labelsForSubmittedChange(