Fix integration merge commit message and author

Merges initiated from parallel builds now generate a proper
commit message reflecting that it's an integration of possibly
several commits.

Also author of the merge commit will be the ci bot, which is initiating
the merge.

Fixes: QTQAINFRA-4346
Change-Id: I69d507979c58cc49bd0117e3d57f49b9e834601a
Reviewed-by: Tor Arne Vestbø <[email protected]>

Author: jujokini

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

@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2019 The Qt Company
+// Copyright (C) 2021 The Qt Company
 //
 
 package com.googlesource.gerrit.plugins.qtcodereview;
@@ -120,7 +120,8 @@ public CodeReviewCommit cherryPickPatch(
         } else {
           logger.atInfo().log("qtcodereview: merge of merge created");
           RevCommit commit =
-              QtUtil.merge(committerIdent, git, oi, revWalk, commitToCherryPick, baseCommit, true);
+              QtUtil.merge(committerIdent, git, oi, revWalk, commitToCherryPick,
+                           baseCommit, null, true);
           cherryPickCommit = revWalk.parseCommit(commit);
           logger.atInfo().log("qtcodereview: %s merged as %s", commitToCherryPick, cherryPickCommit);
         }

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

@@ -1,5 +1,5 @@
 //
-// Copyright (C) 2020 The Qt Company
+// Copyright (C) 2021 The Qt Company
 //
 
 package com.googlesource.gerrit.plugins.qtcodereview;
@@ -237,8 +237,8 @@ private void approveBuildChanges()
 
     ObjectId oldId = git.resolve(destBranchKey.branch());
 
-    Result result =
-        QtUtil.mergeBranches(user.asIdentifiedUser(), git, buildBranchKey, destBranchKey);
+    Result result = QtUtil.mergeBranches(user.asIdentifiedUser(), git, buildBranchKey,
+        destBranchKey, "Merge integration " + buildBranch);
 
     if (result != Result.FAST_FORWARD) {
       message = "Unable to merge this integration because another integration parallel to this one "

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

@@ -1,6 +1,6 @@
 // Copyright (C) 2011 The Android Open Source Project
 // Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
-// Copyright (C) 2020 The Qt Company
+// Copyright (C) 2021 The Qt Company
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -288,7 +288,7 @@ public static Result updateRef(
     return result;
   }
 
-  private String getChangeId(RevCommit commit) {
+  private static String getChangeId(RevCommit commit) {
     List<String> changeIds = commit.getFooterLines(FooterConstants.CHANGE_ID);
     String changeId = null;
     if (!changeIds.isEmpty()) changeId = changeIds.get(0);
@@ -541,6 +541,7 @@ public static RevCommit merge(
       RevWalk revWalk,
       RevCommit toMerge,
       RevCommit mergeTip,
+      String customCommitMessage,
       boolean mergeAlways)
       throws NoSuchRefException, IOException, MergeConflictException {
 
@@ -561,18 +562,20 @@ public static RevCommit merge(
       return toMerge;
     }
 
-    String message;
-    try {
-      message = revWalk.parseCommit(toMerge).getShortMessage();
-    } catch (Exception e) {
-      message = toMerge.toString();
+    String message = customCommitMessage;
+    if (message == null) {
+      try {
+          message = revWalk.parseCommit(toMerge).getShortMessage();
+        } catch (Exception e) {
+          message = toMerge.toString();
+        }
+      message = "Merge \"" + toMerge.toString() + "\"";
     }
-    message = "Merge \"" + message + "\"";
 
     final CommitBuilder mergeCommit = new CommitBuilder();
     mergeCommit.setTreeId(merger.getResultTreeId());
     mergeCommit.setParentIds(mergeTip, toMerge); // important: mergeTip must be parent index 0
-    mergeCommit.setAuthor(toMerge.getAuthorIdent());
+    mergeCommit.setAuthor(committerIdent);
     mergeCommit.setCommitter(committerIdent);
     mergeCommit.setMessage(message);
 
@@ -585,17 +588,22 @@ public static RefUpdate.Result mergeBranches(
       IdentifiedUser user,
       Repository git,
       final BranchNameKey branch,
-      final BranchNameKey destination)
+      final BranchNameKey destination,
+      String customCommitMessage)
       throws NoSuchRefException, IOException, MergeConflictException {
 
     ObjectId srcId = git.resolve(branch.branch());
     if (srcId == null) throw new NoSuchRefException("Invalid Revision: " + branch);
 
-    return mergeObjectToBranch(user, git, srcId, destination);
+    return mergeObjectToBranch(user, git, srcId, destination, customCommitMessage);
   }
 
   private static RefUpdate.Result mergeObjectToBranch(
-      IdentifiedUser user, Repository git, ObjectId srcId, final BranchNameKey destination)
+      IdentifiedUser user,
+      Repository git,
+      ObjectId srcId,
+      final BranchNameKey destination,
+      String customCommitMessage)
       throws NoSuchRefException, IOException, MergeConflictException {
 
     Ref destRef = git.getRefDatabase().getRef(destination.branch());
@@ -613,7 +621,8 @@ private static RefUpdate.Result mergeObjectToBranch(
       PersonIdent committer =
           user.newCommitterIdent(new Timestamp(System.currentTimeMillis()), TimeZone.getDefault());
 
-      RevCommit mergeCommit = merge(committer, git, objInserter, revWalk, toMerge, mergeTip, false);
+      RevCommit mergeCommit = merge(committer, git, objInserter, revWalk, toMerge,
+                                    mergeTip, customCommitMessage, false);
       logger.atInfo().log("qtcodereview: merge commit for %s added to %s", srcId, destination);
 
       RefUpdate refUpdate = git.updateRef(destination.branch());

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

@@ -1,4 +1,4 @@
-// Copyright (C) 2019 The Qt Company
+// Copyright (C) 2021 The Qt Company
 
 package com.googlesource.gerrit.plugins.qtcodereview;
 
@@ -168,16 +168,32 @@ public void parallelBuilds_MergeCommitVerify() throws Exception {
     testRepo.reset(initialHead);
     PushOneCommit.Result c3 = pushCommit("master", "commitmsg3", "file3", "content3");
     approve(c3.getChangeId());
+    PushOneCommit.Result c4 = pushCommit("master", "commitmsg4", "file4", "content4");
+    approve(c4.getChangeId());
+    PushOneCommit.Result c5 = pushCommit("master", "commitmsg5", "file5", "content5");
+    approve(c5.getChangeId());
     QtStage(c3);
+    QtStage(c4);
+    QtStage(c5);
     QtNewBuild("master", "test-build-parallel-3");
 
     RevCommit updatedHead = qtApproveBuild("master", "test-build-parallel-1", c1, false);
+    String commitMessage = updatedHead.getFullMessage();
+    assertThat(commitMessage).doesNotContain("Merge");
+
     updatedHead = qtApproveBuild("master", "test-build-parallel-2", c2, true);
-    updatedHead = qtApproveBuild("master", "test-build-parallel-3", c3, true);
+    commitMessage = updatedHead.getFullMessage();
+    assertThat(commitMessage).contains("Merge integration test-build-parallel-2");
+
+    updatedHead = qtApproveBuild("master", "test-build-parallel-3", c5, true);
+    commitMessage = updatedHead.getFullMessage();
+    assertThat(commitMessage).contains("Merge integration test-build-parallel-3");
 
     assertStatusMerged(c1.getChange().change());
     assertStatusMerged(c2.getChange().change());
     assertStatusMerged(c3.getChange().change());
+    assertStatusMerged(c4.getChange().change());
+    assertStatusMerged(c5.getChange().change());
   }
 
   @Test
@@ -459,8 +475,12 @@ private RevCommit qtApproveBuild(
     if (expectMerge) {
       assertThat(updatedHead.getParentCount()).isEqualTo(2);
       assertCherryPick(updatedHead.getParent(1), expectedContent.getCommit(), null);
+      assertThat(updatedHead.getAuthorIdent().getEmailAddress()).isEqualTo(admin.email());
+      assertThat(updatedHead.getCommitterIdent().getEmailAddress()).isEqualTo(admin.email());
     } else {
       assertCherryPick(updatedHead, expectedContent.getCommit(), null);
+      assertThat(updatedHead.getAuthorIdent().getEmailAddress()).isEqualTo(user.email());
+      assertThat(updatedHead.getCommitterIdent().getEmailAddress()).isEqualTo(user.email());
     }
 
     RevCommit stagingHead = getRemoteRefHead(project, stagingRef);