1 files changed, 65 insertions, 4 deletions

diff --git a/lib/gitlab/git/conflict/resolver.rb b/lib/gitlab/git/conflict/resolver.rb
index 0e4a973301f..c3cb0264112 100644
--- a/lib/gitlab/git/conflict/resolver.rb
+++ b/lib/gitlab/git/conflict/resolver.rb
@@ -12,8 +12,14 @@ module Gitlab
         end
 
         def conflicts
-          @conflicts ||= @target_repository.wrapped_gitaly_errors do
-            gitaly_conflicts_client(@target_repository).list_conflict_files.to_a
+          @conflicts ||= begin
+            @target_repository.gitaly_migrate(:conflicts_list_conflict_files) do |is_enabled|
+              if is_enabled
+                gitaly_conflicts_client(@target_repository).list_conflict_files.to_a
+              else
+                rugged_list_conflict_files
+              end
+            end
           end
         rescue GRPC::FailedPrecondition => e
           raise Gitlab::Git::Conflict::Resolver::ConflictSideMissing.new(e.message)
@@ -22,8 +28,12 @@ module Gitlab
         end
 
         def resolve_conflicts(source_repository, resolution, source_branch:, target_branch:)
-          source_repository.wrapped_gitaly_errors do
-            gitaly_conflicts_client(source_repository).resolve_conflicts(@target_repository, resolution, source_branch, target_branch)
+          source_repository.gitaly_migrate(:conflicts_resolve_conflicts) do |is_enabled|
+            if is_enabled
+              gitaly_conflicts_client(source_repository).resolve_conflicts(@target_repository, resolution, source_branch, target_branch)
+            else
+              rugged_resolve_conflicts(source_repository, resolution, source_branch, target_branch)
+            end
           end
         end
 
@@ -51,6 +61,57 @@ module Gitlab
         def gitaly_conflicts_client(repository)
           repository.gitaly_conflicts_client(@our_commit_oid, @their_commit_oid)
         end
+
+        def write_resolved_file_to_index(repository, index, file, params)
+          if params[:sections]
+            resolved_lines = file.resolve_lines(params[:sections])
+            new_file = resolved_lines.map { |line| line[:full_line] }.join("\n")
+
+            new_file << "\n" if file.our_blob.data.end_with?("\n")
+          elsif params[:content]
+            new_file = file.resolve_content(params[:content])
+          end
+
+          our_path = file.our_path
+
+          oid = repository.rugged.write(new_file, :blob)
+          index.add(path: our_path, oid: oid, mode: file.our_mode)
+          index.conflict_remove(our_path)
+        end
+
+        def rugged_list_conflict_files
+          target_index = @target_repository.rugged.merge_commits(@our_commit_oid, @their_commit_oid)
+
+          # We don't need to do `with_repo_branch_commit` here, because the target
+          # project always fetches source refs when creating merge request diffs.
+          conflict_files(@target_repository, target_index)
+        end
+
+        def rugged_resolve_conflicts(source_repository, resolution, source_branch, target_branch)
+          source_repository.with_repo_branch_commit(@target_repository, target_branch) do
+            index = source_repository.rugged.merge_commits(@our_commit_oid, @their_commit_oid)
+            conflicts = conflict_files(source_repository, index)
+
+            resolution.files.each do |file_params|
+              conflict_file = conflict_for_path(conflicts, file_params[:old_path], file_params[:new_path])
+
+              write_resolved_file_to_index(source_repository, index, conflict_file, file_params)
+            end
+
+            unless index.conflicts.empty?
+              missing_files = index.conflicts.map { |file| file[:ours][:path] }
+
+              raise ResolutionError, "Missing resolutions for the following files: #{missing_files.join(', ')}"
+            end
+
+            commit_params = {
+              message: resolution.commit_message,
+              parents: [@our_commit_oid, @their_commit_oid]
+            }
+
+            source_repository.commit_index(resolution.user, source_branch, index, commit_params)
+          end
+        end
       end
     end
   end