public CodeReviewCommit createCherryPickFromCommit(
Repository repo,
ObjectInserter inserter,
RevCommit mergeTip,
RevCommit originalCommit,
PersonIdent cherryPickCommitterIdent,
String commitMsg,
CodeReviewRevWalk rw)
throws MissingObjectException, IncorrectObjectTypeException, IOException,
MergeIdenticalTreeException, MergeConflictException {
final ThreeWayMerger m = newThreeWayMerger(repo, inserter);
m.setBase(originalCommit.getParent(0));
if (m.merge(mergeTip, originalCommit)) {
ObjectId tree = m.getResultTreeId();
if (tree.equals(mergeTip.getTree())) {
throw new MergeIdenticalTreeException("identical tree");
}
CommitBuilder mergeCommit = new CommitBuilder();
mergeCommit.setTreeId(tree);
mergeCommit.setParentId(mergeTip);
mergeCommit.setAuthor(originalCommit.getAuthorIdent());
mergeCommit.setCommitter(cherryPickCommitterIdent);
mergeCommit.setMessage(commitMsg);
return rw.parseCommit(commit(inserter, mergeCommit));
} else {
throw new MergeConflictException("merge conflict");
}
}
@Override
public ChangeKind load(Key key) throws IOException {
if (Objects.equal(key.prior, key.next)) {
return ChangeKind.NO_CODE_CHANGE;
}
RevWalk walk = new RevWalk(key.repo);
try {
RevCommit prior = walk.parseCommit(key.prior);
walk.parseBody(prior);
RevCommit next = walk.parseCommit(key.next);
walk.parseBody(next);
if (!next.getFullMessage().equals(prior.getFullMessage())) {
if (next.getTree() == prior.getTree() && isSameParents(prior, next)) {
return ChangeKind.NO_CODE_CHANGE;
} else {
return ChangeKind.REWORK;
}
}
if (prior.getParentCount() != 1 || next.getParentCount() != 1) {
// Trivial rebases done by machine only work well on 1 parent.
return ChangeKind.REWORK;
}
if (next.getTree() == prior.getTree() && isSameParents(prior, next)) {
return ChangeKind.TRIVIAL_REBASE;
}
// A trivial rebase can be detected by looking for the next commit
// having the same tree as would exist when the prior commit is
// cherry-picked onto the next commit's new first parent.
ThreeWayMerger merger =
MergeUtil.newThreeWayMerger(
key.repo, MergeUtil.createDryRunInserter(), key.strategyName);
merger.setBase(prior.getParent(0));
if (merger.merge(next.getParent(0), prior)
&& merger.getResultTreeId().equals(next.getTree())) {
return ChangeKind.TRIVIAL_REBASE;
} else {
return ChangeKind.REWORK;
}
} finally {
key.repo = null;
walk.release();
}
}
public boolean canCherryPick(
MergeSorter mergeSorter,
Repository repo,
CodeReviewCommit mergeTip,
CodeReviewRevWalk rw,
CodeReviewCommit toMerge)
throws IntegrationException {
if (mergeTip == null) {
// The branch is unborn. Fast-forward is possible.
//
return true;
}
if (toMerge.getParentCount() == 0) {
// Refuse to merge a root commit into an existing branch,
// we cannot obtain a delta for the cherry-pick to apply.
//
return false;
}
if (toMerge.getParentCount() == 1) {
// If there is only one parent, a cherry-pick can be done by
// taking the delta relative to that one parent and redoing
// that on the current merge tip.
//
try {
ThreeWayMerger m = newThreeWayMerger(repo, createDryRunInserter(repo));
m.setBase(toMerge.getParent(0));
return m.merge(mergeTip, toMerge);
} catch (IOException e) {
throw new IntegrationException("Cannot merge " + toMerge.name(), e);
}
}
// There are multiple parents, so this is a merge commit. We
// don't want to cherry-pick the merge as clients can't easily
// rebase their history with that merge present and replaced
// by an equivalent merge with a different first parent. So
// instead behave as though MERGE_IF_NECESSARY was configured.
//
return canFastForward(mergeSorter, mergeTip, rw, toMerge)
|| canMerge(mergeSorter, repo, mergeTip, toMerge);
}