Fix resolving accounts sometimes creating duplicate records for a given AP id (#15364)

* Fix ResolveAccountService accepting mismatching acct: URI

* Set attributes that should be updated regardless of suspension

* Fix key fetching

* Automatically merge remote accounts with duplicate `uri`

* Add tests

* Add "tootctl accounts fix-duplicates"

Finds duplicate accounts sharing a same ActivityPub `id`, re-fetch them and
merge them under the canonical `acct:` URI.

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

spec/services/resolve_account_service_spec.rb

@@ -60,7 +60,22 @@ RSpec.describe ResolveAccountService, type: :service do
 
   context 'with a legitimate webfinger redirection' do
     before do
-      webfinger = { subject: 'acct:foo@ap.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo' }] }
+      webfinger = { subject: 'acct:foo@ap.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo', type: 'application/activity+json' }] }
+      stub_request(:get, 'https://redirected.example.com/.well-known/webfinger?resource=acct:Foo@redirected.example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
+    end
+
+    it 'returns new remote account' do
+      account = subject.call('Foo@redirected.example.com')
+
+      expect(account.activitypub?).to eq true
+      expect(account.acct).to eq 'foo@ap.example.com'
+      expect(account.inbox_url).to eq 'https://ap.example.com/users/foo/inbox'
+    end
+  end
+
+  context 'with a misconfigured redirection' do
+    before do
+      webfinger = { subject: 'acct:Foo@redirected.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo', type: 'application/activity+json' }] }
       stub_request(:get, 'https://redirected.example.com/.well-known/webfinger?resource=acct:Foo@redirected.example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
     end
 
@@ -75,9 +90,9 @@ RSpec.describe ResolveAccountService, type: :service do
 
   context 'with too many webfinger redirections' do
     before do
-      webfinger = { subject: 'acct:foo@evil.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo' }] }
+      webfinger = { subject: 'acct:foo@evil.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo', type: 'application/activity+json' }] }
       stub_request(:get, 'https://redirected.example.com/.well-known/webfinger?resource=acct:Foo@redirected.example.com').to_return(body: Oj.dump(webfinger), headers: { 'Content-Type': 'application/jrd+json' })
-      webfinger2 = { subject: 'acct:foo@ap.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo' }] }
+      webfinger2 = { subject: 'acct:foo@ap.example.com', links: [{ rel: 'self', href: 'https://ap.example.com/users/foo', type: 'application/activity+json' }] }
       stub_request(:get, 'https://evil.example.com/.well-known/webfinger?resource=acct:foo@evil.example.com').to_return(body: Oj.dump(webfinger2), headers: { 'Content-Type': 'application/jrd+json' })
     end
 
@@ -111,6 +126,41 @@ RSpec.describe ResolveAccountService, type: :service do
     end
   end
 
+  context 'with an already-known actor changing acct: URI' do
+    let!(:duplicate) { Fabricate(:account, username: 'foo', domain: 'old.example.com', uri: 'https://ap.example.com/users/foo') }
+    let!(:status)    { Fabricate(:status, account: duplicate, text: 'foo') }
+
+    it 'returns new remote account' do
+      account = subject.call('foo@ap.example.com')
+
+      expect(account.activitypub?).to eq true
+      expect(account.domain).to eq 'ap.example.com'
+      expect(account.inbox_url).to eq 'https://ap.example.com/users/foo/inbox'
+      expect(account.uri).to eq 'https://ap.example.com/users/foo'
+    end
+
+    it 'merges accounts' do
+      account = subject.call('foo@ap.example.com')
+
+      expect(status.reload.account_id).to eq account.id
+      expect(Account.where(uri: account.uri).count).to eq 1
+    end
+  end
+
+  context 'with an already-known acct: URI changing ActivityPub id' do
+    let!(:old_account) { Fabricate(:account, username: 'foo', domain: 'ap.example.com', uri: 'https://old.example.com/users/foo', last_webfingered_at: nil) }
+    let!(:status)    { Fabricate(:status, account: old_account, text: 'foo') }
+
+    it 'returns new remote account' do
+      account = subject.call('foo@ap.example.com')
+
+      expect(account.activitypub?).to eq true
+      expect(account.domain).to eq 'ap.example.com'
+      expect(account.inbox_url).to eq 'https://ap.example.com/users/foo/inbox'
+      expect(account.uri).to eq 'https://ap.example.com/users/foo'
+    end
+  end
+
   it 'processes one remote account at a time using locks' do
     wait_for_start = true
     fail_occurred  = false