Fix edits with no actual changes being allowed (#17843)

* Fix edits with no actual changes being allowed locally

* Fix edits with no actual changes being allowed through ActivityPub

* Fix false positive changes caused by description processing in model

* Fix not recording poll expiration update

* Fix test

* Revert changes to ProcessStatusUpdateService

* Various fixes and improvements

* Fix code style issues

* Various changes and improvements

* Add guard clause

spec/models/media_attachment_spec.rb

@@ -186,14 +186,6 @@ RSpec.describe MediaAttachment, type: :model do
     expect(media.valid?).to be false
   end
 
-  describe 'descriptions for remote attachments' do
-    it 'are cut off at 1500 characters' do
-      media = Fabricate(:media_attachment, description: 'foo' * 1000, remote_url: 'http://example.com/blah.jpg')
-
-      expect(media.description.size).to be <= 1_500
-    end
-  end
-
   describe 'size limit validation' do
     it 'rejects video files that are too large' do
       stub_const 'MediaAttachment::IMAGE_LIMIT', 100.megabytes

spec/services/activitypub/process_status_update_service_spec.rb

@@ -46,6 +46,29 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService, type: :service do
       expect(status.reload.spoiler_text).to eq 'Show more'
     end
 
+    context 'with no changes at all' do
+      let(:payload) do
+        {
+          '@context': 'https://www.w3.org/ns/activitystreams',
+          id: 'foo',
+          type: 'Note',
+          content: 'Hello world',
+        }
+      end
+
+      before do
+        subject.call(status, json)
+      end
+
+      it 'does not create any edits' do
+        expect(status.reload.edits).to be_empty
+      end
+
+      it 'does not mark status as edited' do
+        expect(status.edited?).to be false
+      end
+    end
+
     context 'with no changes and originally with no ordered_media_attachment_ids' do
       let(:payload) do
         {
@@ -61,8 +84,12 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService, type: :service do
         subject.call(status, json)
       end
 
-      it 'does not record an update' do
-        expect(status.reload.edited?).to be false
+      it 'does not create any edits' do
+        expect(status.reload.edits).to be_empty
+      end
+
+      it 'does not mark status as edited' do
+        expect(status.edited?).to be false
       end
     end
 

spec/services/update_status_service_spec.rb

@@ -3,6 +3,23 @@ require 'rails_helper'
 RSpec.describe UpdateStatusService, type: :service do
   subject { described_class.new }
 
+  context 'when nothing changes' do
+    let!(:status) { Fabricate(:status, text: 'Foo', language: 'en') }
+
+    before do
+      allow(ActivityPub::DistributionWorker).to receive(:perform_async)
+      subject.call(status, status.account_id, text: 'Foo')
+    end
+
+    it 'does not create an edit' do
+      expect(status.reload.edits).to be_empty
+    end
+
+    it 'does not notify anyone' do
+      expect(ActivityPub::DistributionWorker).to_not have_received(:perform_async)
+    end
+  end
+
   context 'when text changes' do
     let!(:status) { Fabricate(:status, text: 'Foo') }
     let(:preview_card) { Fabricate(:preview_card) }