Merge "Support specifying the parent for a cherry-pick in the REST API"

Documentation/rest-api-changes.txt

@@ -4860,11 +4860,13 @@ Which patchset (if any) generated this message.
 === CherryPickInput
 The `CherryPickInput` entity contains information for cherry-picking a change to a new branch.
 
-[options="header",cols="1,6"]
+[options="header",cols="1,^1,5"]
 |===========================
-|Field Name    |Description
+|Field Name         ||Description
-|`message`     |Commit message for the cherry-picked change
+|`message`          ||Commit message for the cherry-picked change
-|`destination` |Destination branch
+|`destination`      ||Destination branch
+|`parent`           |optional, defaults to 1|
+Number of the parent relative to which the cherry-pick should be considered.
 |===========================
 
 [[comment-info]]

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/revision/RevisionIT.java

@@ -26,6 +26,8 @@ import static org.eclipse.jgit.lib.Constants.HEAD;
 import static org.junit.Assert.fail;
 
 import com.google.common.base.Joiner;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Iterables;
 import com.google.gerrit.acceptance.AbstractDaemonTest;
 import com.google.gerrit.acceptance.PushOneCommit;
@@ -47,9 +49,11 @@ import com.google.gerrit.extensions.common.DiffInfo;
 import com.google.gerrit.extensions.common.FileInfo;
 import com.google.gerrit.extensions.common.MergeableInfo;
 import com.google.gerrit.extensions.common.RevisionInfo;
+import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.BinaryResult;
 import com.google.gerrit.extensions.restapi.ETagView;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
+import com.google.gerrit.reviewdb.client.Branch;
 import com.google.gerrit.server.change.GetRevisionActions;
 import com.google.gerrit.server.change.RevisionResource;
 import com.google.inject.Inject;
@@ -356,6 +360,111 @@ public class RevisionIT extends AbstractDaemonTest {
         .isEqualTo("a");
   }
 
+  @Test
+  public void cherryPickMergeRelativeToDefaultParent() throws Exception {
+    String parent1FileName = "a.txt";
+    String parent2FileName = "b.txt";
+    PushOneCommit.Result mergeChangeResult =
+        createCherryPickableMerge(parent1FileName, parent2FileName);
+
+    String cherryPickBranchName = "branch_for_cherry_pick";
+    createBranch(new Branch.NameKey(project, cherryPickBranchName));
+
+    CherryPickInput cherryPickInput = new CherryPickInput();
+    cherryPickInput.destination = cherryPickBranchName;
+    cherryPickInput.message = "Cherry-pick a merge commit to another branch";
+
+    ChangeInfo cherryPickedChangeInfo = gApi.changes()
+        .id(mergeChangeResult.getChangeId())
+        .current()
+        .cherryPick(cherryPickInput)
+        .get();
+
+    Map<String, FileInfo> cherryPickedFilesByName =
+        cherryPickedChangeInfo.revisions
+            .get(cherryPickedChangeInfo.currentRevision)
+            .files;
+    assertThat(cherryPickedFilesByName).containsKey(parent2FileName);
+    assertThat(cherryPickedFilesByName).doesNotContainKey(parent1FileName);
+  }
+
+  @Test
+  public void cherryPickMergeRelativeToSpecificParent() throws Exception {
+    String parent1FileName = "a.txt";
+    String parent2FileName = "b.txt";
+    PushOneCommit.Result mergeChangeResult =
+        createCherryPickableMerge(parent1FileName, parent2FileName);
+
+    String cherryPickBranchName = "branch_for_cherry_pick";
+    createBranch(new Branch.NameKey(project, cherryPickBranchName));
+
+    CherryPickInput cherryPickInput = new CherryPickInput();
+    cherryPickInput.destination = cherryPickBranchName;
+    cherryPickInput.message = "Cherry-pick a merge commit to another branch";
+    cherryPickInput.parent = 2;
+
+    ChangeInfo cherryPickedChangeInfo = gApi.changes()
+        .id(mergeChangeResult.getChangeId())
+        .current()
+        .cherryPick(cherryPickInput)
+        .get();
+
+    Map<String, FileInfo> cherryPickedFilesByName =
+        cherryPickedChangeInfo.revisions
+            .get(cherryPickedChangeInfo.currentRevision)
+            .files;
+    assertThat(cherryPickedFilesByName).containsKey(parent1FileName);
+    assertThat(cherryPickedFilesByName).doesNotContainKey(parent2FileName);
+  }
+
+  @Test
+  public void cherryPickMergeUsingInvalidParent() throws Exception {
+    String parent1FileName = "a.txt";
+    String parent2FileName = "b.txt";
+    PushOneCommit.Result mergeChangeResult =
+        createCherryPickableMerge(parent1FileName, parent2FileName);
+
+    String cherryPickBranchName = "branch_for_cherry_pick";
+    createBranch(new Branch.NameKey(project, cherryPickBranchName));
+
+    CherryPickInput cherryPickInput = new CherryPickInput();
+    cherryPickInput.destination = cherryPickBranchName;
+    cherryPickInput.message = "Cherry-pick a merge commit to another branch";
+    cherryPickInput.parent = 0;
+
+    exception.expect(BadRequestException.class);
+    exception.expectMessage("Cherry Pick: Parent 0 does not exist. Please"
+        + " specify a parent in range [1, 2].");
+    gApi.changes()
+        .id(mergeChangeResult.getChangeId())
+        .current()
+        .cherryPick(cherryPickInput);
+  }
+
+  @Test
+  public void cherryPickMergeUsingNonExistentParent() throws Exception {
+    String parent1FileName = "a.txt";
+    String parent2FileName = "b.txt";
+    PushOneCommit.Result mergeChangeResult =
+        createCherryPickableMerge(parent1FileName, parent2FileName);
+
+    String cherryPickBranchName = "branch_for_cherry_pick";
+    createBranch(new Branch.NameKey(project, cherryPickBranchName));
+
+    CherryPickInput cherryPickInput = new CherryPickInput();
+    cherryPickInput.destination = cherryPickBranchName;
+    cherryPickInput.message = "Cherry-pick a merge commit to another branch";
+    cherryPickInput.parent = 3;
+
+    exception.expect(BadRequestException.class);
+    exception.expectMessage("Cherry Pick: Parent 3 does not exist. Please"
+        + " specify a parent in range [1, 2].");
+    gApi.changes()
+        .id(mergeChangeResult.getChangeId())
+        .current()
+        .cherryPick(cherryPickInput);
+  }
+
   @Test
   public void canRebase() throws Exception {
     PushOneCommit push = pushFactory.create(db, admin.getIdent(), testRepo);
@@ -806,4 +915,35 @@ public class RevisionIT extends AbstractDaemonTest {
     assertDiffForNewFile(diff, pushResult.getCommit(), path,
         expectedContentSideB);
   }
+
+  private PushOneCommit.Result createCherryPickableMerge(String parent1FileName,
+      String parent2FileName) throws Exception {
+    RevCommit initialCommit = getHead(repo());
+
+    String branchAName = "branchA";
+    createBranch(new Branch.NameKey(project, branchAName));
+    String branchBName = "branchB";
+    createBranch(new Branch.NameKey(project, branchBName));
+
+    PushOneCommit.Result changeAResult = pushFactory
+        .create(db, admin.getIdent(), testRepo, "change a",
+            parent1FileName, "Content of a")
+        .to("refs/for/" + branchAName);
+
+    testRepo.reset(initialCommit);
+    PushOneCommit.Result changeBResult = pushFactory
+        .create(db, admin.getIdent(), testRepo, "change b",
+            parent2FileName, "Content of b")
+        .to("refs/for/" + branchBName);
+
+    PushOneCommit pushableMergeCommit = pushFactory.create(db, admin.getIdent(),
+        testRepo, "merge", ImmutableMap.of(parent1FileName, "Content of a",
+            parent2FileName, "Content of b"));
+    pushableMergeCommit.setParents(ImmutableList.of(changeAResult.getCommit(),
+        changeBResult.getCommit()));
+    PushOneCommit.Result mergeChangeResult =
+        pushableMergeCommit.to("refs/for/" + branchAName);
+    mergeChangeResult.assertOkStatus();
+    return mergeChangeResult;
+  }
 }

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/changes/CherryPickInput.java

@@ -17,4 +17,5 @@ package com.google.gerrit.extensions.api.changes;
 public class CherryPickInput {
   public String message;
   public String destination;
+  public Integer parent;
 }

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

@@ -60,10 +60,12 @@ public class CherryPick implements RestModifyView<RevisionResource, CherryPickIn
   public ChangeInfo apply(RevisionResource revision, CherryPickInput input)
       throws OrmException, IOException, UpdateException, RestApiException {
     final ChangeControl control = revision.getControl();
+    int parent = input.parent == null ? 1 : input.parent;
 
     if (input.message == null || input.message.trim().isEmpty()) {
       throw new BadRequestException("message must be non-empty");
-    } else if (input.destination == null || input.destination.trim().isEmpty()) {
+    } else if (input.destination == null
+        || input.destination.trim().isEmpty()) {
       throw new BadRequestException("destination must be non-empty");
     }
 
@@ -91,7 +93,7 @@ public class CherryPick implements RestModifyView<RevisionResource, CherryPickIn
       Change.Id cherryPickedChangeId =
           cherryPickChange.cherryPick(revision.getChange(),
               revision.getPatchSet(), input.message, refName,
-              refControl);
+              refControl, parent);
       return json.create(ChangeJson.NO_OPTIONS).format(revision.getProject(),
           cherryPickedChangeId);
     } catch (InvalidChangeOperationException e) {

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

@@ -114,8 +114,8 @@ public class CherryPickChange {
   }
 
   public Change.Id cherryPick(Change change, PatchSet patch,
-      final String message, final String ref,
+      final String message, final String ref, final RefControl refControl,
-      final RefControl refControl) throws NoSuchChangeException,
+      int parent) throws NoSuchChangeException,
       OrmException, MissingObjectException,
       IncorrectObjectTypeException, IOException,
       InvalidChangeOperationException, IntegrationException, UpdateException,
@@ -147,6 +147,13 @@ public class CherryPickChange {
       CodeReviewCommit commitToCherryPick =
           revWalk.parseCommit(ObjectId.fromString(patch.getRevision().get()));
 
+      if (parent <= 0 || parent > commitToCherryPick.getParentCount()) {
+        throw new InvalidChangeOperationException(String.format(
+            "Cherry Pick: Parent %s does not exist. Please specify a parent in"
+                + " range [1, %s].",
+            parent, commitToCherryPick.getParentCount()));
+      }
+
       Timestamp now = TimeUtil.nowTs();
       PersonIdent committerIdent =
           identifiedUser.newCommitterIdent(now, serverTimeZone);
@@ -160,10 +167,12 @@ public class CherryPickChange {
 
       CodeReviewCommit cherryPickCommit;
       try {
-        ProjectState projectState = refControl.getProjectControl().getProjectState();
+        ProjectState projectState = refControl.getProjectControl()
-        cherryPickCommit =
+            .getProjectState();
-            mergeUtilFactory.create(projectState).createCherryPickFromCommit(git, oi, mergeTip,
+        cherryPickCommit = mergeUtilFactory.create(projectState)
-                commitToCherryPick, committerIdent, commitMessage, revWalk);
+            .createCherryPickFromCommit(git, oi, mergeTip,
+                commitToCherryPick, committerIdent, commitMessage, revWalk,
+                parent - 1);
 
         Change.Key changeKey;
         final List<String> idList = cherryPickCommit.getFooterLines(

gerrit-server/src/main/java/com/google/gerrit/server/git/MergeUtil.java

@@ -184,13 +184,13 @@ public class MergeUtil {
   public CodeReviewCommit createCherryPickFromCommit(Repository repo,
       ObjectInserter inserter, RevCommit mergeTip, RevCommit originalCommit,
       PersonIdent cherryPickCommitterIdent, String commitMsg,
-      CodeReviewRevWalk rw)
+      CodeReviewRevWalk rw, int parentIndex)
       throws MissingObjectException, IncorrectObjectTypeException, IOException,
       MergeIdenticalTreeException, MergeConflictException {
 
     final ThreeWayMerger m = newThreeWayMerger(repo, inserter);
 
-    m.setBase(originalCommit.getParent(0));
+    m.setBase(originalCommit.getParent(parentIndex));
     if (m.merge(mergeTip, originalCommit)) {
       ObjectId tree = m.getResultTreeId();
       if (tree.equals(mergeTip.getTree())) {

gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/CherryPick.java

@@ -107,7 +107,7 @@ public class CherryPick extends SubmitStrategy {
       try {
         newCommit = args.mergeUtil.createCherryPickFromCommit(
             args.repo, args.inserter, args.mergeTip.getCurrentTip(), toMerge,
-            committer, cherryPickCmtMsg, args.rw);
+            committer, cherryPickCmtMsg, args.rw, 0);
       } catch (MergeConflictException mce) {
         // Keep going in the case of a single merge failure; the goal is to
         // cherry-pick as many commits as possible.