From a697e7aa564b0b112855bee09fe7ec435f8346d3 Mon Sep 17 00:00:00 2001
From: Leeeft <877059692@qq.com>
Date: Wed, 26 Mar 2025 20:55:58 +0800
Subject: [PATCH] The `buildWithBodyBytes` method may introduce an issue with
 the body length; therefore, it is advisable to revert to the previous `build`
 method.

---
 in_session.go   |  2 +-
 message.go      | 15 ---------------
 message_test.go | 35 -----------------------------------
 3 files changed, 1 insertion(+), 51 deletions(-)

diff --git a/in_session.go b/in_session.go
index 5445967cd..39f0b3c4f 100644
--- a/in_session.go
+++ b/in_session.go
@@ -259,7 +259,7 @@ func (state inSession) resendMessages(session *session, beginSeqNo, endSeqNo int
 		}
 
 		session.log.OnEventf("Resending Message: %v", sentMessageSeqNum)
-		msgBytes = msg.buildWithBodyBytes(msg.bodyBytes) // workaround for maintaining repeating group field order
+		msgBytes = msg.build()
 		session.EnqueueBytesAndSend(msgBytes)
 
 		seqNum = sentMessageSeqNum + 1
diff --git a/message.go b/message.go
index 3e1e7202b..7b673601d 100644
--- a/message.go
+++ b/message.go
@@ -597,21 +597,6 @@ func (m *Message) build() []byte {
 	return b.Bytes()
 }
 
-// Constructs a []byte from a Message instance, using the given bodyBytes.
-// This is a workaround for the fact that we currently rely on the generated Message types to properly serialize/deserialize RepeatingGroups.
-// In other words, we cannot go from bytes to a Message then back to bytes, which is exactly what we need to do in the case of a Resend.
-// This func lets us pull the Message from the Store, parse it, update the Header, and then build it back into bytes using the original Body.
-// Note: The only standard non-Body group is NoHops.  If that is used in the Header, this workaround may fail.
-func (m *Message) buildWithBodyBytes(bodyBytes []byte) []byte {
-	m.cook()
-
-	var b bytes.Buffer
-	m.Header.write(&b)
-	b.Write(bodyBytes)
-	m.Trailer.write(&b)
-	return b.Bytes()
-}
-
 func (m *Message) cook() {
 	bodyLength := m.Header.length() + m.Body.length() + m.Trailer.length()
 	m.Header.SetInt(tagBodyLength, bodyLength)
diff --git a/message_test.go b/message_test.go
index b02508cd9..477746967 100644
--- a/message_test.go
+++ b/message_test.go
@@ -383,41 +383,6 @@ func (s *MessageSuite) TestRebuildDoubleNestedWithTwoMembersRepeatingGroupWithDi
 	s.True(bytes.Equal(expectedBytes, rebuildBytes), "Unexpected bytes,\n expected: %s\n but got: %s", expectedBytes, rebuildBytes)
 }
 
-func (s *MessageSuite) TestReBuildWithRepeatingGroupForResend() {
-	// Given the following message with a repeating group
-	origHeader := "8=FIXT.1.1
9=161
35=8
34=3
49=ISLD
52=20240415-03:43:17.923
56=TW
"
-	origBody := "6=1.00
11=1
14=1.00
17=1
31=1.00
32=1.00
37=1
38=1.00
39=2
54=1
55=1
150=2
151=0.00
453=1
448=xyzzy
447=D
452=1
"
-	origTrailer := "10=014
"
-	rawMsg := bytes.NewBufferString(origHeader + origBody + origTrailer)
-
-	// When I reparse the message from the store during a resend request
-	s.Nil(ParseMessage(s.msg, rawMsg))
-
-	// And I update the headers for resend
-	s.msg.Header.SetField(tagOrigSendingTime, FIXString("20240415-03:43:17.923"))
-	s.msg.Header.SetField(tagSendingTime, FIXString("20240415-14:41:23.456"))
-	s.msg.Header.SetField(tagPossDupFlag, FIXBoolean(true))
-
-	// When I rebuild the message
-	rebuildBytes := s.msg.build()
-
-	// Then the repeating groups will not be in the correct order in the rebuilt message (note tags 447, 448, 452, 453)
-	expectedBytes := []byte("8=FIXT.1.1
9=192
35=8
34=3
43=Y
49=ISLD
52=20240415-14:41:23.456
56=TW
122=20240415-03:43:17.923
6=1.00
11=1
14=1.00
17=1
31=1.00
32=1.00
37=1
38=1.00
39=2
54=1
55=1
150=2
151=0.00
453=1
448=xyzzy
447=D
452=1
10=018
")
-	s.False(bytes.Equal(expectedBytes, rebuildBytes), "Unexpected bytes,\n expected: %s\n  but was: %s", expectedBytes, rebuildBytes)
-	expectedOutOfOrderBytes := []byte("8=FIXT.1.1
9=192
35=8
34=3
43=Y
49=ISLD
52=20240415-14:41:23.456
56=TW
122=20240415-03:43:17.923
6=1.00
11=1
14=1.00
17=1
31=1.00
32=1.00
37=1
38=1.00
39=2
54=1
55=1
150=2
151=0.00
447=D
448=xyzzy
452=1
453=1
10=018
")
-	s.True(bytes.Equal(expectedOutOfOrderBytes, rebuildBytes), "Unexpected bytes,\n expected: %s\n  but was: %s", expectedOutOfOrderBytes, rebuildBytes)
-
-	// But the bodyBytes will still be correct
-	origBodyBytes := []byte(origBody)
-	s.True(bytes.Equal(origBodyBytes, s.msg.bodyBytes), "Incorrect body bytes, \n expected: %s\n  but was: %s", origBodyBytes, s.msg.bodyBytes)
-
-	// So when I combine the updated header + the original bodyBytes + the as-is trailer
-	resendBytes := s.msg.buildWithBodyBytes(s.msg.bodyBytes)
-
-	// Then the reparsed, rebuilt message will retain the correct ordering of repeating group tags during resend
-	s.True(bytes.Equal(expectedBytes, resendBytes), "Unexpected bytes,\n expected: %s\n  but was: %s", expectedBytes, resendBytes)
-}
-
 func (s *MessageSuite) TestReverseRoute() {
 	s.Nil(ParseMessage(s.msg, bytes.NewBufferString("8=FIX.4.2
9=171
35=D
34=2
49=TW
50=KK
52=20060102-15:04:05
56=ISLD
57=AP
144=BB
115=JCD
116=CS
128=MG
129=CB
142=JV
143=RY
145=BH
11=ID
21=3
38=100
40=w
54=1
55=INTC
60=20060102-15:04:05
10=123
")))