Merge branch 'operation-service-merge' into 'master'

Prepare Repository#merge for migration to Gitaly

Closes gitaly#559

See merge request gitlab-org/gitlab-ce!14154

2 files changed, 43 insertions, 1 deletions

diff --git a/lib/gitlab/git/operation_service.rb b/lib/gitlab/git/operation_service.rb
index 347e3b5165e..dcdec818f5e 100644
--- a/lib/gitlab/git/operation_service.rb
+++ b/lib/gitlab/git/operation_service.rb
@@ -1,6 +1,11 @@
 module Gitlab
   module Git
     class OperationService
+      WithBranchResult = Struct.new(:newrev, :repo_created, :branch_created) do
+        alias_method :repo_created?, :repo_created
+        alias_method :branch_created?, :branch_created
+      end
+
       attr_reader :user, :repository
 
       def initialize(user, new_repository)
@@ -107,7 +112,7 @@ module Gitlab
         ref = Gitlab::Git::BRANCH_REF_PREFIX + branch_name
         update_ref_in_hooks(ref, newrev, oldrev)
 
-        [newrev, was_empty, was_empty || Gitlab::Git.blank_ref?(oldrev)]
+        WithBranchResult.new(newrev, was_empty, was_empty || Gitlab::Git.blank_ref?(oldrev))
       end
 
       def find_oldrev_from_branch(newrev, branch)
diff --git a/lib/gitlab/git/repository.rb b/lib/gitlab/git/repository.rb
index 32a265b15f2..c499ff101b5 100644
--- a/lib/gitlab/git/repository.rb
+++ b/lib/gitlab/git/repository.rb
@@ -653,6 +653,43 @@ module Gitlab
         tags.find { |tag| tag.name == name }
       end
 
+      def merge(user, source_sha, target_branch, message)
+        committer = Gitlab::Git.committer_hash(email: user.email, name: user.name)
+
+        OperationService.new(user, self).with_branch(target_branch) do |start_commit|
+          our_commit = start_commit.sha
+          their_commit = source_sha
+
+          raise 'Invalid merge target' unless our_commit
+          raise 'Invalid merge source' unless their_commit
+
+          merge_index = rugged.merge_commits(our_commit, their_commit)
+          break if merge_index.conflicts?
+
+          options = {
+            parents: [our_commit, their_commit],
+            tree: merge_index.write_tree(rugged),
+            message: message,
+            author: committer,
+            committer: committer
+          }
+
+          commit_id = create_commit(options)
+
+          yield commit_id
+
+          commit_id
+        end
+      rescue Gitlab::Git::CommitError # when merge_index.conflicts?
+        nil
+      end
+
+      def create_commit(params = {})
+        params[:message].delete!("\r")
+
+        Rugged::Commit.create(rugged, params)
+      end
+
       # Delete the specified branch from the repository
       def delete_branch(branch_name)
         gitaly_migrate(:delete_branch) do |is_enabled|