Fix rejection of staged changes after successful integration

Staging ref rebuild logic did not take into account that
current branch head is now always ancestor of the old staging ref

Fixes: QTQAINFRA-4384
Change-Id: I13d47219119abd7add54fd85354c02503718bc55
Reviewed-by: Paul Wicking <[email protected]>
Reviewed-by: Daniel Smith <[email protected]>

Author: jujokini

src/main/java/com/googlesource/gerrit/plugins/qtcodereview/QtUtil.java

@@ -313,6 +313,7 @@ private List<ChangeData> arrangeOrderLikeInRef(
     if (refObj.equals(tipObj)) return results;
 
     RevWalk revWalk = new RevWalk(git);
+    RevCommit branchHead = revWalk.parseCommit(tipObj);
     RevCommit commit = revWalk.parseCommit(refObj);
     int count = 0;
     do {
@@ -331,7 +332,7 @@ private List<ChangeData> arrangeOrderLikeInRef(
         // It can always be trusted that parent in index 0 is the correct one
         commit = revWalk.parseCommit(commit.getParent(0));
       }
-    } while (commit != null && !commit.equals(tipObj) && count < 100);
+    } while (commit != null && !revWalk.isMergedInto(commit, branchHead) && count < 100);
 
     if (count == 100) return null;
     return results;
@@ -376,7 +377,10 @@ private ObjectId findReusableStagingHead(
 
     ObjectId reusableHead = null;
     RevWalk revWalk = new RevWalk(git);
+    RevCommit branch = revWalk.parseCommit(branchHead);
     RevCommit commit = revWalk.parseCommit(stagingHead);
+    if (!revWalk.isMergedInto(branch, commit)) return branchHead;
+
     int count = 0;
     do {
       count++;

src/test/java/com/googlesource/gerrit/plugins/qtcodereview/QtCodeReviewIT.java

@@ -4,6 +4,8 @@
 
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.Truth.assertWithMessage;
+import static com.google.gerrit.acceptance.GitUtil.assertPushOk;
+import static com.google.gerrit.acceptance.GitUtil.pushHead;
 import static com.google.gerrit.extensions.client.ListChangesOption.CURRENT_COMMIT;
 import static com.google.gerrit.extensions.client.ListChangesOption.CURRENT_REVISION;
 import static com.google.gerrit.extensions.client.ListChangesOption.DETAILED_LABELS;
@@ -54,6 +56,8 @@ public class QtCodeReviewIT extends LightweightPluginDaemonTest {
   protected static final String BUILD_PASS_MESSAGE = "thebuildpassed";
   protected static final String BUILD_FAIL_MESSAGE = "thebuildfailed";
 
+  private RevCommit lastGeneratedCommit;
+
   @Before
   public void ReduceLogging() throws Exception {
     LogManager.resetConfiguration();
@@ -72,6 +76,25 @@ public void ReduceLogging() throws Exception {
     root.addAppender(dst);
   }
 
+  @Before
+  public void GenerateCommits() throws Exception {
+    // Generate 100+ commits to match more like production environment
+    RevCommit parent = getRemoteHead();
+    for (int i = 0; i <= 101; i++) {
+      RevCommit c = testRepo.commit()
+          .message("a commit " + String.valueOf(i))
+          .add("afile" + String.valueOf(i), "somecontent")
+          .parent(parent)
+          .insertChangeId()
+          .create();
+      testRepo.reset(c);
+      assertPushOk(pushHead(testRepo, "refs/heads/master", false), "refs/heads/master");
+      parent = c;
+    }
+    lastGeneratedCommit = parent;
+    resetEvents();
+  }
+
   @Test
   public void dummyTest() throws Exception {}
 
@@ -296,7 +319,7 @@ protected void assertApproval(String changeId, TestAccount user) throws Exceptio
   protected void assertReviewedByFooter(RevCommit commit, boolean exists) {
 
     // Skip initial commit and merge commits
-    if (commit.getParentCount() != 1) return;
+    if (commit.getParentCount() != 1 || commit.equals(lastGeneratedCommit)) return;
 
     List<String> changeIds = commit.getFooterLines(FooterConstants.REVIEWED_BY);
     assertThat(!changeIds.isEmpty()).isEqualTo(exists);