Merge commit 'eb118d85238da8d0583868abab2756bb329742ba' into glitch-soc/merge-upstream

Conflicts:
- `yarn.lock`:
  Upstream updated dependencies textually adjacent to glitch-soc-only ones.
  Updated them as upstream did.

app/serializers/activitypub/note_serializer.rb

@@ -2,6 +2,7 @@
 
 class ActivityPub::NoteSerializer < ActivityPub::Serializer
   include FormattingHelper
+  include JsonLdHelper
 
   context_extensions :atom_uri, :conversation, :sensitive, :voters_count, :quotes, :interaction_policies, :direct_message
 
@@ -9,7 +10,7 @@ class ActivityPub::NoteSerializer < ActivityPub::Serializer
              :in_reply_to, :published, :url,
              :attributed_to, :to, :cc, :sensitive,
              :atom_uri, :in_reply_to_atom_uri,
-             :conversation
+             :conversation, :context
 
   attribute :content
   attribute :content_map, if: :language?
@@ -171,10 +172,18 @@ class ActivityPub::NoteSerializer < ActivityPub::Serializer
     if object.conversation.uri?
       object.conversation.uri
     else
-      OStatus::TagManager.instance.unique_tag(object.conversation.created_at, object.conversation.id, 'Conversation')
+      # This means `parent_status_id` and `parent_account_id` must *not* get backfilled
+      ActivityPub::TagManager.instance.uri_for(object.conversation) || OStatus::TagManager.instance.unique_tag(object.conversation.created_at, object.conversation.id, 'Conversation')
     end
   end
 
+  def context
+    return if object.conversation.nil?
+
+    uri = ActivityPub::TagManager.instance.uri_for(object.conversation)
+    uri unless unsupported_uri_scheme?(uri)
+  end
+
   def local?
     object.account.local?
   end