Add latest changes from gitlab-org/gitlab@master

4 files changed, 110 insertions, 0 deletions

diff --git a/app/services/discussions/capture_diff_note_position_service.rb b/app/services/discussions/capture_diff_note_position_service.rb
new file mode 100644
index 00000000000..273a60f7e55
--- /dev/null
+++ b/app/services/discussions/capture_diff_note_position_service.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+module Discussions
+  class CaptureDiffNotePositionService
+    def initialize(merge_request, paths)
+      @project = merge_request.project
+      @tracer = build_tracer(merge_request, paths)
+    end
+
+    def execute(discussion)
+      # The service has been implemented for text only
+      # The impact of image notes on this service is being investigated in
+      # https://gitlab.com/gitlab-org/gitlab/-/issues/213989
+      return unless discussion.on_text?
+
+      result = tracer&.trace(discussion.position)
+      return unless result
+
+      position = result[:position]
+
+      # Currently position data is copied across all notes of a discussion
+      # It makes sense to store a position only for the first note instead
+      # Within the newly introduced table we can start doing just that
+      DiffNotePosition.create_or_update_for(discussion.notes.first,
+        diff_type: :head,
+        position: position,
+        line_code: position.line_code(project.repository))
+    end
+
+    private
+
+    attr_reader :tracer, :project
+
+    def build_tracer(merge_request, paths)
+      return if paths.blank?
+
+      old_diff_refs, new_diff_refs = build_diff_refs(merge_request)
+
+      return unless old_diff_refs && new_diff_refs
+
+      Gitlab::Diff::PositionTracer.new(
+        project: project,
+        old_diff_refs: old_diff_refs,
+        new_diff_refs: new_diff_refs,
+        paths: paths.uniq)
+    end
+
+    def build_diff_refs(merge_request)
+      merge_ref_head = merge_request.merge_ref_head
+      return unless merge_ref_head
+
+      start_sha, base_sha = merge_ref_head.parent_ids
+      new_diff_refs = Gitlab::Diff::DiffRefs.new(
+        base_sha: base_sha,
+        start_sha: start_sha,
+        head_sha: merge_ref_head.id)
+
+      old_diff_refs = merge_request.diff_refs
+
+      return if new_diff_refs == old_diff_refs
+
+      [old_diff_refs, new_diff_refs]
+    end
+  end
+end
diff --git a/app/services/discussions/capture_diff_note_positions_service.rb b/app/services/discussions/capture_diff_note_positions_service.rb
new file mode 100644
index 00000000000..3684a3f679a
--- /dev/null
+++ b/app/services/discussions/capture_diff_note_positions_service.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+module Discussions
+  class CaptureDiffNotePositionsService
+    def initialize(merge_request)
+      @merge_request = merge_request
+    end
+
+    def execute
+      return unless merge_request.has_complete_diff_refs?
+
+      discussions, paths = build_discussions
+
+      service = Discussions::CaptureDiffNotePositionService.new(merge_request, paths)
+
+      discussions.each do |discussion|
+        service.execute(discussion)
+      end
+    end
+
+    private
+
+    attr_reader :merge_request
+
+    def build_discussions
+      active_diff_discussions = merge_request.notes.new_diff_notes.discussions.select do |discussion|
+        discussion.active?(merge_request.diff_refs)
+      end
+      paths = active_diff_discussions.flat_map { |n| n.diff_file.paths }
+
+      [active_diff_discussions, paths]
+    end
+  end
+end
diff --git a/app/services/merge_requests/mergeability_check_service.rb b/app/services/merge_requests/mergeability_check_service.rb
index 5b79e4d01f2..d3d661a3b75 100644
--- a/app/services/merge_requests/mergeability_check_service.rb
+++ b/app/services/merge_requests/mergeability_check_service.rb
@@ -118,11 +118,18 @@ module MergeRequests
 
       if can_git_merge? && merge_to_ref
         merge_request.mark_as_mergeable
+        update_diff_discussion_positions!
       else
         merge_request.mark_as_unmergeable
       end
     end
 
+    def update_diff_discussion_positions!
+      return if Feature.disabled?(:merge_ref_head_comments, merge_request.target_project)
+
+      Discussions::CaptureDiffNotePositionsService.new(merge_request).execute
+    end
+
     def recheck!
       if !merge_request.recheck_merge_status? && outdated_merge_ref?
         merge_request.mark_as_unchecked
diff --git a/app/services/notes/create_service.rb b/app/services/notes/create_service.rb
index 80bc4485988..6c1f52ec866 100644
--- a/app/services/notes/create_service.rb
+++ b/app/services/notes/create_service.rb
@@ -65,6 +65,10 @@ module Notes
       if Feature.enabled?(:notes_create_service_tracking, project)
         Gitlab::Tracking.event('Notes::CreateService', 'execute', tracking_data_for(note))
       end
+
+      if Feature.enabled?(:merge_ref_head_comments, project) && note.for_merge_request? && note.diff_note? && note.start_of_discussion?
+        Discussions::CaptureDiffNotePositionService.new(note.noteable, note.diff_file&.paths).execute(note.discussion)
+      end
     end
 
     def do_commands(note, update_params, message, only_commands)