fix(GODT-2576): Correctly handle Forwarded messages from Thunderbird

Thunderbird uses `In-Reply-To` with `X-Forwarded-Message-Id` to signal
to the SMTP server that it is forwarding a message.

go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/Masterminds/semver/v3 v3.2.0
 	github.com/ProtonMail/gluon v0.17.1-0.20231114153341-2ecbdd2739f7
 	github.com/ProtonMail/go-autostart v0.0.0-20210130080809-00ed301c8e9a
-	github.com/ProtonMail/go-proton-api v0.4.1-0.20231116074655-c9bc6f71eef0
+	github.com/ProtonMail/go-proton-api v0.4.1-0.20231116144214-8a47c8d92fbc
 	github.com/ProtonMail/gopenpgp/v2 v2.7.4-proton
 	github.com/PuerkitoBio/goquery v1.8.1
 	github.com/abiosoft/ishell v2.0.0+incompatible

go.sum

@@ -36,8 +36,8 @@ github.com/ProtonMail/go-message v0.13.1-0.20230526094639-b62c999c85b7 h1:+j+Kd/
 github.com/ProtonMail/go-message v0.13.1-0.20230526094639-b62c999c85b7/go.mod h1:NBAn21zgCJ/52WLDyed18YvYFm5tEoeDauubFqLokM4=
 github.com/ProtonMail/go-mime v0.0.0-20230322103455-7d82a3887f2f h1:tCbYj7/299ekTTXpdwKYF8eBlsYsDVoggDAuAjoK66k=
 github.com/ProtonMail/go-mime v0.0.0-20230322103455-7d82a3887f2f/go.mod h1:gcr0kNtGBqin9zDW9GOHcVntrwnjrK+qdJ06mWYBybw=
-github.com/ProtonMail/go-proton-api v0.4.1-0.20231116074655-c9bc6f71eef0 h1:tUK7x2Vm2bnCdij/gKyXxgV9v1A680BdDOEQfBm1Rz0=
+github.com/ProtonMail/go-proton-api v0.4.1-0.20231116144214-8a47c8d92fbc h1:GBRKoFAldApEMkMrsFN1ZxG0eG797w6LTv/dFMDcsqQ=
-github.com/ProtonMail/go-proton-api v0.4.1-0.20231116074655-c9bc6f71eef0/go.mod h1:WEXJqj5DSc2YI77SgXdpMY0nk33Qy92Vu2r4tOEazA8=
+github.com/ProtonMail/go-proton-api v0.4.1-0.20231116144214-8a47c8d92fbc/go.mod h1:WEXJqj5DSc2YI77SgXdpMY0nk33Qy92Vu2r4tOEazA8=
 github.com/ProtonMail/go-smtp v0.0.0-20231109081432-2b3d50599865 h1:EP1gnxLL5Z7xBSymE9nSTM27nRYINuvssAtDmG0suD8=
 github.com/ProtonMail/go-smtp v0.0.0-20231109081432-2b3d50599865/go.mod h1:qm27SGYgoIPRot6ubfQ/GpiPy/g3PaZAVRxiO/sDUgQ=
 github.com/ProtonMail/go-srp v0.0.7 h1:Sos3Qk+th4tQR64vsxGIxYpN3rdnG9Wf9K4ZloC1JrI=

internal/services/smtp/smtp.go

@@ -217,7 +217,7 @@ func (s *Service) sendWithKey(
 		return proton.Message{}, fmt.Errorf("unsupported MIME type: %v", message.MIMEType)
 	}
 
-	draft, err := s.createDraft(ctx, addrKR, emails, from, to, parentID, message.InReplyTo, proton.DraftTemplate{
+	draft, err := s.createDraft(ctx, addrKR, emails, from, to, parentID, message.InReplyTo, message.XForward, proton.DraftTemplate{
 		Subject:  message.Subject,
 		Body:     decBody,
 		MIMEType: message.MIMEType,
@@ -353,6 +353,7 @@ func (s *Service) createDraft(
 	to []string,
 	parentID string,
 	replyToID string,
+	xForwardID string,
 	template proton.DraftTemplate,
 ) (proton.Message, error) {
 	// Check sender: set the sender if it's missing.
@@ -388,7 +389,12 @@ func (s *Service) createDraft(
 	var action proton.CreateDraftAction
 
 	if len(replyToID) > 0 {
+		// Thunderbird fills both ReplyTo and adds an X-Forwarded-Message-Id header when forwarding.
+		if replyToID == xForwardID {
+			action = proton.ForwardAction
+		} else {
 			action = proton.ReplyAction
+		}
 	} else {
 		action = proton.ForwardAction
 	}

pkg/message/parser.go

@@ -60,6 +60,7 @@ type Message struct {
 	References []string
 	ExternalID string
 	InReplyTo  string
+	XForward   string
 }
 
 type Attachment struct {
@@ -520,6 +521,9 @@ func parseMessageHeader(h message.Header, allowInvalidAddressLists bool) (Messag
 		case "in-reply-to":
 			m.InReplyTo = regexp.MustCompile("<(.*)>").ReplaceAllString(fields.Value(), "$1")
 
+		case "x-forwarded-message-id":
+			m.XForward = regexp.MustCompile("<(.*)>").ReplaceAllString(fields.Value(), "$1")
+
 		case "references":
 			for _, ref := range strings.Fields(fields.Value()) {
 				for _, ref := range strings.Split(ref, ",") {

pkg/message/parser_test.go

@@ -786,6 +786,16 @@ func TestParseTextPlainWithDocxAttachmentCyrillic(t *testing.T) {
 	assert.Equal(t, "АБВГДЃЕЖЗЅИЈКЛЉМНЊОПРСТЌУФХЧЏЗШ.docx", m.Attachments[0].Name)
 }
 
+func TestParseInReplyToAndXForward(t *testing.T) {
+	f := getFileReader("text_plain_utf8_reply_to_and_x_forward.eml")
+
+	m, err := Parse(f)
+	require.NoError(t, err)
+
+	require.Equal(t, "00000@protonmail.com", m.XForward)
+	require.Equal(t, "00000@protonmail.com", m.InReplyTo)
+}
+
 func TestPatchNewLineWithHtmlBreaks(t *testing.T) {
 	{
 		input := []byte("\nfoo\nbar\n\n\nzz\nddd")

pkg/message/testdata/text_plain_utf8_reply_to_and_x_forward.eml

@@ -0,0 +1,7 @@
+From: Sender <sender@pm.me>
+To: Receiver <receiver@pm.me>
+Content-Type: text/plain; charset=utf-8
+X-Forwarded-Message-Id: <00000@protonmail.com>
+In-Reply-To: <00000@protonmail.com>
+
+body

tests/features/smtp/send/send_reply.feature

@@ -278,3 +278,112 @@ Feature: SMTP send reply
       | from                  | subject                 | in-reply-to              | references                |
       | [user:user2]@[domain] | FW - Please Reply       | <something@external.com> | <something@external.com>  |
       | [user:user2]@[domain] | FW - Please Reply Again | <something@external.com> | <something@external.com>  |
+
+  @long-black
+  Scenario: Reply with In-Reply-To and X-Forwarded-Message-Id sets forwarded flag
+    # User1 send the initial message.
+    When SMTP client "1" sends the following message from "[user:user1]@[domain]" to "[user:user2]@[domain]":
+      """
+      From: Bridge Test <[user:user1]@[domain]>
+      To: Internal Bridge <[user:user2]@[domain]>
+      Subject: Please Reply
+      Message-ID: <something@external.com>
+
+      hello
+
+      """
+    Then it succeeds
+    Then IMAP client "1" eventually sees the following messages in "Sent":
+      | from                  | to                    | subject            | message-id               |
+      | [user:user1]@[domain] | [user:user2]@[domain] | Please Reply       | <something@external.com> |
+    # login user2.
+    And the user logs in with username "[user:user2]" and password "password"
+    And user "[user:user2]" connects and authenticates IMAP client "2"
+    And user "[user:user2]" connects and authenticates SMTP client "2"
+    And user "[user:user2]" finishes syncing
+    # User2 receive the message.
+    Then IMAP client "2" eventually sees the following messages in "INBOX":
+      | from                  |  subject           | message-id              | reply-to               |
+      | [user:user1]@[domain] | Please Reply       | <something@external.com> | [user:user1]@[domain] |
+    # User2 reply to it.
+    When SMTP client "2" sends the following message from "[user:user2]@[domain]" to "[user:user1]@[domain]":
+      """
+      From: Internal Bridge <[user:user2]@[domain]>
+      To: Bridge Test <[user:user1]@[domain]>
+      Content-Type: text/plain
+      Subject: FW - Please Reply
+      In-Reply-To: <something@external.com>
+      Message-ID: <something@external.com>
+      X-Forwarded-Message-Id: <something@external.com>
+
+      Heya
+
+      """
+    Then it succeeds
+    Then IMAP client "2" eventually sees the following messages in "Sent":
+      | from                  | to                    | subject                 | in-reply-to              | references               |
+      | [user:user2]@[domain] | [user:user1]@[domain] | FW - Please Reply       | <something@external.com> | <something@external.com> |
+    When IMAP client "2" selects "INBOX"
+    And it succeeds
+    Then IMAP client "2" eventually sees that message at row 1 has the flag "forwarded"
+    And it succeeds
+    Then IMAP client "2" eventually sees that message at row 1 does not have the flag "\Answered"
+    And it succeeds
+    # User1 receive the reply.|
+    And IMAP client "1" eventually sees the following messages in "INBOX":
+      | from                  | subject                 | in-reply-to              | references                |
+      | [user:user2]@[domain] | FW - Please Reply       | <something@external.com> | <something@external.com>  |
+
+  @long-black
+  Scenario: Reply with In-Reply-To sets answered flag
+    # User1 send the initial message.
+    When SMTP client "1" sends the following message from "[user:user1]@[domain]" to "[user:user2]@[domain]":
+      """
+      From: Bridge Test <[user:user1]@[domain]>
+      To: Internal Bridge <[user:user2]@[domain]>
+      Subject: Please Reply
+      Message-ID: <something@external.com>
+
+      hello
+
+      """
+    Then it succeeds
+    Then IMAP client "1" eventually sees the following messages in "Sent":
+      | from                  | to                    | subject            | message-id               |
+      | [user:user1]@[domain] | [user:user2]@[domain] | Please Reply       | <something@external.com> |
+    # login user2.
+    And the user logs in with username "[user:user2]" and password "password"
+    And user "[user:user2]" connects and authenticates IMAP client "2"
+    And user "[user:user2]" connects and authenticates SMTP client "2"
+    And user "[user:user2]" finishes syncing
+    # User2 receive the message.
+    Then IMAP client "2" eventually sees the following messages in "INBOX":
+      | from                  |  subject           | message-id              | reply-to               |
+      | [user:user1]@[domain] | Please Reply       | <something@external.com> | [user:user1]@[domain] |
+    # User2 reply to it.
+    When SMTP client "2" sends the following message from "[user:user2]@[domain]" to "[user:user1]@[domain]":
+      """
+      From: Internal Bridge <[user:user2]@[domain]>
+      To: Bridge Test <[user:user1]@[domain]>
+      Content-Type: text/plain
+      Subject: FW - Please Reply
+      In-Reply-To: <something@external.com>
+      Message-ID: <something@external.com>
+
+      Heya
+
+      """
+    Then it succeeds
+    Then IMAP client "2" eventually sees the following messages in "Sent":
+      | from                  | to                    | subject                 | in-reply-to              | references               |
+      | [user:user2]@[domain] | [user:user1]@[domain] | FW - Please Reply       | <something@external.com> | <something@external.com> |
+    When IMAP client "2" selects "INBOX"
+    And it succeeds
+    Then IMAP client "2" eventually sees that message at row 1 has the flag "\Answered"
+    And it succeeds
+    Then IMAP client "2" eventually sees that message at row 1 does not have the flag "forwarded"
+    And it succeeds
+    # User1 receive the reply.|
+    And IMAP client "1" eventually sees the following messages in "INBOX":
+      | from                  | subject                 | in-reply-to              | references                |
+      | [user:user2]@[domain] | FW - Please Reply       | <something@external.com> | <something@external.com>  |