Fix processing of object updates with duplicate hashtags (#37756)

app/services/activitypub/process_status_update_service.rb

@@ -208,7 +208,7 @@ class ActivityPub::ProcessStatusUpdateService < BaseService
       Tag.find_or_create_by_names([tag]).filter(&:valid?)
     rescue ActiveRecord::RecordInvalid
       []
-    end
+    end.uniq
 
     return unless @status.distributable?
 

spec/services/activitypub/process_status_update_service_spec.rb

@@ -259,6 +259,8 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
             { type: 'Hashtag', name: 'foo' },
             { type: 'Hashtag', name: 'bar' },
             { type: 'Hashtag', name: '#2024' },
+            { type: 'Hashtag', name: 'Foo Bar' },
+            { type: 'Hashtag', name: 'FooBar' },
           ],
         }
       end
@@ -270,7 +272,7 @@ RSpec.describe ActivityPub::ProcessStatusUpdateService do
 
       it 'updates tags and featured tags' do
         expect { subject.call(status, json, json) }
-          .to change { status.tags.reload.pluck(:name) }.from(contain_exactly('test', 'foo')).to(contain_exactly('foo', 'bar'))
+          .to change { status.tags.reload.pluck(:name) }.from(contain_exactly('test', 'foo')).to(contain_exactly('foo', 'bar', 'foobar'))
           .and change { status.account.featured_tags.find_by(name: 'test').statuses_count }.by(-1)
           .and change { status.account.featured_tags.find_by(name: 'bar').statuses_count }.by(1)
           .and change { status.account.featured_tags.find_by(name: 'bar').last_status_at }.from(nil).to(be_present)