AbstractQueryChangesTest: Add coverage for parentproject: predicate

Bug: Issue 8605
Change-Id: I9300b70ce3b56e6dd02a93ff30c858d8041d2239
diff --git a/gerrit-server/src/test/java/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java b/gerrit-server/src/test/java/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java
index beb8cdd..a10d629 100644
--- a/gerrit-server/src/test/java/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java
+++ b/gerrit-server/src/test/java/com/google/gerrit/server/query/change/AbstractQueryChangesTest.java
@@ -50,6 +50,7 @@
 import com.google.gerrit.extensions.api.changes.ReviewInput.RobotCommentInput;
 import com.google.gerrit.extensions.api.changes.StarsInput;
 import com.google.gerrit.extensions.api.groups.GroupInput;
+import com.google.gerrit.extensions.api.projects.ProjectInput;
 import com.google.gerrit.extensions.client.ProjectWatchInfo;
 import com.google.gerrit.extensions.client.ReviewerState;
 import com.google.gerrit.extensions.common.ChangeInfo;
@@ -526,6 +527,17 @@
   }
 
   @Test
+  public void byParentProject() throws Exception {
+    TestRepository<Repo> repo1 = createProject("repo1");
+    TestRepository<Repo> repo2 = createProject("repo2", "repo1");
+    Change change1 = insert(repo1, newChange(repo1));
+    Change change2 = insert(repo2, newChange(repo2));
+
+    assertQuery("parentproject:repo1", change2, change1);
+    assertQuery("parentproject:repo2", change2);
+  }
+
+  @Test
   public void byProjectPrefix() throws Exception {
     TestRepository<Repo> repo1 = createProject("repo1");
     TestRepository<Repo> repo2 = createProject("repo2");
@@ -2168,6 +2180,14 @@
     return new TestRepository<>(repoManager.openRepository(new Project.NameKey(name)));
   }
 
+  protected TestRepository<Repo> createProject(String name, String parent) throws Exception {
+    ProjectInput input = new ProjectInput();
+    input.name = name;
+    input.parent = parent;
+    gApi.projects().create(input).get();
+    return new TestRepository<>(repoManager.openRepository(new Project.NameKey(name)));
+  }
+
   protected QueryRequest newQuery(Object query) {
     return gApi.changes().query(query.toString());
   }