Add participation to root.author on receiving reshare

When author of the root post receives a reshare to it, no participation is added to the root author on the reshare. This causes any comments on the reshare on remote pods not to be sent to the author. Adding a participation should subscribe to the reshare and thus bring added comments back to the author.

closes #6481

Changelog.md

@@ -8,6 +8,7 @@
 * Fix notifications for interactions by non-contacts [#6498](https://github.com/diaspora/diaspora/pull/6498)
 * Fix issue where the publisher was broken on profile pages [#6503](https://github.com/diaspora/diaspora/pull/6503)
 * Prevent participations being created for invalid interactions [#6552](https://github.com/diaspora/diaspora/pull/6552)
+* Improve federation for reshare related interactions [#6481](https://github.com/diaspora/diaspora/pull/6481)
 
 ## Features
 

app/models/reshare.rb

@@ -56,6 +56,7 @@ class Reshare < Post
   def receive(recipient, sender)
     local_reshare = Reshare.where(:guid => self.guid).first
     if local_reshare && local_reshare.root.author_id == recipient.person.id
+      recipient.participate! self
       return unless recipient.has_contact_for?(sender)
     end
     super(recipient, sender)

spec/models/reshare_spec.rb

@@ -50,7 +50,8 @@ describe Reshare, :type => :model do
       receive_reshare
       expect(@root.resharers).to include(@reshare.author)
     end
-    it 'does not error if the root author has a contact for the resharer' do
+
+    it "does not error if the root author has a contact for the resharer" do
       bob.share_with @reshare.author, bob.aspects.first
       expect {
         Timeout.timeout(5) do
@@ -58,6 +59,12 @@ describe Reshare, :type => :model do
         end
       }.not_to raise_error
     end
+
+    it "participates root author in the reshare" do
+      receive_reshare
+      participations = Participation.where(target_id: @reshare.id, author_id: @root.author_id)
+      expect(participations.count).to eq(1)
+    end
   end
 
   describe '#nsfw' do