Return project in GetRelated

This commit adds project as a mandatory return field in
RelatedChangeAndCommitInfo returned by GetRelated to fix a bug where
links to related changes would have 'undefined' as the project component.

Since we now always want to have the project along the change number it
seems to be a good practice to also return the project along with a
change number in the API similar to ChangeInfo.

Bug: Issue 6876
Change-Id: I64ac0d1b30a3b8034cf16afe96c9d1168cbde193

Documentation/rest-api-changes.txt

@@ -3548,6 +3548,7 @@ describing the related changes.
   {
     "changes": [
       {
+        "project": "gerrit",
         "change_id": "Ic62ae3103fca2214904dbf2faf4c861b5f0ae9b5",
         "commit": {
           "commit": "78847477532e386f5a2185a4e8c90b2509e354e3",
@@ -3570,6 +3571,7 @@ describing the related changes.
         "status": "NEW"
       },
       {
+        "project": "gerrit",
         "change_id": "I5e4fc08ce34d33c090c9e0bf320de1b17309f774",
         "commit": {
           "commit": "b1cb4caa6be46d12b94c25aa68aebabcbb3f53fe",
@@ -6577,6 +6579,7 @@ a related change and commit.
 [options="header",cols="1,^1,5"]
 |===========================
 |Field Name                ||Description
+|`project`                 ||The project of the change or commit.
 |`change_id`               |optional|The Change-Id of the change.
 |`commit`                  ||The commit as a
 link:#commit-info[CommitInfo] entity.

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/server/change/GetRelatedIT.java

@@ -563,9 +563,10 @@ public class GetRelatedIT extends AbstractDaemonTest {
     return Iterables.getOnlyElement(queryProvider.get().byCommit(c));
   }
 
-  private static ChangeAndCommit changeAndCommit(
+  private ChangeAndCommit changeAndCommit(
       PatchSet.Id psId, ObjectId commitId, int currentRevisionNum) {
     ChangeAndCommit result = new ChangeAndCommit();
+    result.project = project.get();
     result._changeNumber = psId.getParentKey().get();
     result.commit = new CommitInfo();
     result.commit.commit = commitId.name();
@@ -599,6 +600,7 @@ public class GetRelatedIT extends AbstractDaemonTest {
       String name = "index " + i + " related to " + psId;
       ChangeAndCommit a = actual.get(i);
       ChangeAndCommit e = expected[i];
+      assertThat(a.project).named("project of " + name).isEqualTo(e.project);
       assertThat(a._changeNumber).named("change ID of " + name).isEqualTo(e._changeNumber);
       // Don't bother checking changeId; assume _changeNumber is sufficient.
       assertThat(a._revisionNumber).named("revision of " + name).isEqualTo(e._revisionNumber);

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

@@ -21,6 +21,7 @@ import com.google.gerrit.extensions.common.CommitInfo;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.CommonConverters;
 import com.google.gerrit.server.PatchSetUtil;
@@ -102,7 +103,7 @@ public class GetRelated implements RestReadView<RevisionResource> {
       } else {
         commit = d.commit();
       }
-      result.add(new ChangeAndCommit(d.data().change(), ps, commit));
+      result.add(new ChangeAndCommit(rsrc.getProject(), d.data().change(), ps, commit));
     }
 
     if (result.size() == 1) {
@@ -137,6 +138,7 @@ public class GetRelated implements RestReadView<RevisionResource> {
   }
 
   public static class ChangeAndCommit {
+    public String project;
     public String changeId;
     public CommitInfo commit;
     public Integer _changeNumber;
@@ -146,7 +148,10 @@ public class GetRelated implements RestReadView<RevisionResource> {
 
     public ChangeAndCommit() {}
 
-    ChangeAndCommit(@Nullable Change change, @Nullable PatchSet ps, RevCommit c) {
+    ChangeAndCommit(
+        Project.NameKey project, @Nullable Change change, @Nullable PatchSet ps, RevCommit c) {
+      this.project = project.get();
+
       if (change != null) {
         changeId = change.getKey().get();
         _changeNumber = change.getChangeId();
@@ -171,6 +176,7 @@ public class GetRelated implements RestReadView<RevisionResource> {
     @Override
     public String toString() {
       return MoreObjects.toStringHelper(this)
+          .add("project", project)
           .add("changeId", changeId)
           .add("commit", toString(commit))
           .add("_changeNumber", _changeNumber)