1 files changed, 58 insertions, 15 deletions

diff --git a/app/helpers/notes_helper.rb b/app/helpers/notes_helper.rb
index e85ba76887d..2302e65c537 100644
--- a/app/helpers/notes_helper.rb
+++ b/app/helpers/notes_helper.rb
@@ -24,23 +24,55 @@ module NotesHelper
     }.to_json
   end
 
-  def link_to_new_diff_note(line_code, line_type = nil)
-    discussion_id = LegacyDiffNote.build_discussion_id(
-      @comments_target[:noteable_type],
-      @comments_target[:noteable_id] || @comments_target[:commit_id],
-      line_code
-    )
+  def link_to_new_diff_note(line_code, position, line_type = nil)
+    use_legacy_diff_note = @use_legacy_diff_notes
+    # If the controller doesn't force the use of legacy diff notes, we
+    # determine this on a line-by-line basis by seeing if there already exist
+    # active legacy diff notes at this line, in which case newly created notes
+    # will use the legacy technology as well.
+    # We do this because the discussion_id values of legacy and "new" diff
+    # notes, which are used to group notes on the merge request discussion tab,
+    # are incompatible.
+    # If we didn't, diff notes that would show for the same line on the changes
+    # tab, would show in different discussions on the discussion tab.
+    use_legacy_diff_note ||= begin
+      line_diff_notes = @grouped_diff_notes[line_code]
+      line_diff_notes && line_diff_notes.any?(&:legacy_diff_note?)
+    end
 
     data = {
       noteable_type: @comments_target[:noteable_type],
       noteable_id:   @comments_target[:noteable_id],
       commit_id:     @comments_target[:commit_id],
       line_type:     line_type,
-      line_code:     line_code,
-      note_type:     LegacyDiffNote.name,
-      discussion_id: discussion_id
+      line_code:     line_code
     }
 
+    if use_legacy_diff_note
+      discussion_id = LegacyDiffNote.build_discussion_id(
+        @comments_target[:noteable_type],
+        @comments_target[:noteable_id] || @comments_target[:commit_id],
+        line_code
+      )
+
+      data.merge!(
+        note_type: LegacyDiffNote.name,
+        discussion_id: discussion_id
+      )
+    else
+      discussion_id = DiffNote.build_discussion_id(
+        @comments_target[:noteable_type],
+        @comments_target[:noteable_id] || @comments_target[:commit_id],
+        position
+      )
+
+      data.merge!(
+        position: position.to_json,
+        note_type: DiffNote.name,
+        discussion_id: discussion_id
+      )
+    end
+
     button_tag(class: 'btn add-diff-note js-add-diff-note-button',
                data: data,
                title: 'Add a comment to this line') do
@@ -60,14 +92,15 @@ module NotesHelper
     }
 
     if note.diff_note?
-      data.merge!(
-        line_code: note.line_code,
-        note_type: LegacyDiffNote.name
-      )
+      data[:note_type] = note.type
+
+      data.merge!(note.diff_attributes)
     end
 
-    button_tag 'Reply...', class: 'btn btn-text-field js-discussion-reply-button',
-                           data: data, title: 'Add a reply'
+    content_tag(:div, class: "discussion-reply-holder") do
+      button_tag 'Reply...', class: 'btn btn-text-field js-discussion-reply-button',
+                             data: data, title: 'Add a reply'
+    end
   end
 
   def note_max_access_for_user(note)
@@ -79,4 +112,14 @@ module NotesHelper
     full_key = { project: note.project, user_id: note.author_id }
     @max_access_by_user_id[full_key]
   end
+
+  def diff_note_path(note)
+    return unless note.diff_note?
+
+    if note.for_merge_request? && note.active?
+      diffs_namespace_project_merge_request_path(note.project.namespace, note.project, note.noteable, anchor: note.line_code)
+    elsif note.for_commit?
+      namespace_project_commit_path(note.project.namespace, note.project, note.noteable, anchor: note.line_code)
+    end
+  end
 end