ParseGroup: Body field after nested repeating group

message.go

@@ -310,6 +310,7 @@ func parseGroup(mp *msgParser, tags []Tag) {
 	dm := mp.msg.fields[mp.fieldIndex : mp.fieldIndex+1]
 	fields := getGroupFields(mp.msg, tags, mp.appDataDictionary)
 
+parseLoop:
 	for {
 		mp.fieldIndex++
 		mp.parsedFieldBytes = &mp.msg.fields[mp.fieldIndex]
@@ -350,16 +351,15 @@ func parseGroup(mp *msgParser, tags []Tag) {
 				fields = getGroupFields(mp.msg, searchTags, mp.appDataDictionary)
 				continue
 			}
-			if len(tags) > 1 {
-				searchTags = tags[:len(tags)-1]
-			}
-			// Did this tag occur after a nested group and belongs to the parent group.
-			if isNumInGroupField(mp.msg, searchTags, mp.appDataDictionary) {
-				// Add the field member to the group.
-				dm = append(dm, *mp.parsedFieldBytes)
-				// Continue parsing the parent group.
-				fields = getGroupFields(mp.msg, searchTags, mp.appDataDictionary)
-				continue
+			// The tag isn't a member of the current group. Walk up: if an
+			// ancestor group includes it, resume there; otherwise it's body-level.
+			for len(tags) > 1 {
+				tags = tags[:len(tags)-1]
+				fields = getGroupFields(mp.msg, tags, mp.appDataDictionary)
+				if isGroupMember(mp.parsedFieldBytes.tag, fields) {
+					dm = append(dm, *mp.parsedFieldBytes)
+					continue parseLoop
+				}
 			}
 			// Add the repeating group.
 			mp.msg.Body.add(dm)

message_test.go

@@ -113,6 +113,45 @@ func (s *MessageSuite) TestParseOutOfOrder() {
 	s.Nil(ParseMessage(s.msg, rawMsg))
 }
 
+func (s *MessageSuite) TestParseGroup_BodyFieldAfterNestedGroup() {
+	dict, dictErr := datadictionary.Parse("spec/FIX44.xml")
+	s.Nil(dictErr)
+
+	// Wire layout (FIX 4.4 MassQuoteAcknowledgement):
+	//   117=QID              QuoteID (body)
+	//   296=1                NoQuoteSets count (body group)
+	//     302=SET1           QuoteSetID (inside NoQuoteSets)
+	//     295=1              NoQuoteEntries count (nested group)
+	//       299=E1           QuoteEntryID (inside NoQuoteEntries)
+	//       132=100          BidPx (inside NoQuoteEntries)
+	//       133=101          OfferPx (inside NoQuoteEntries)
+	//   297=0                QuoteStatus (BODY level, AFTER the group)
+	rawMsg := bytes.NewBufferString(
+		"8=FIX.4.4
9=63
35=b
117=QID
" +
+			"296=1
302=SET1
" +
+			"295=1
299=E1
132=100
133=101
" +
+			"297=1
" +
+			"10=002
")
+
+	err := ParseMessageWithDataDictionary(s.msg, rawMsg, dict, dict)
+	s.Nil(err)
+
+	rebuildBytes := s.msg.build()
+	expectedBytes := rawMsg.Bytes()
+	s.True(bytes.Equal(expectedBytes, rebuildBytes), "Unexpected bytes,\n +%s\n -%s", rebuildBytes, expectedBytes)
+
+	// NoQuoteSets count (group delimiter) lands in Body as expected.
+	s.True(s.msg.Body.Has(Tag(296)))
+
+	// QuoteStatus (297) must be a top-level body field per FIX 4.4.
+	s.True(s.msg.Body.Has(Tag(297)),
+		"QuoteStatus (297) must land at the body level; it is a body field "+
+			"in MassQuoteAcknowledgement, not a member of NoQuoteSets.")
+	val, verr := s.msg.Body.GetInt(Tag(297))
+	s.Nil(verr)
+	s.Equal(1, val)
+}
+
 func (s *MessageSuite) TestBuild() {
 	s.msg.Header.SetField(tagBeginString, FIXString(BeginStringFIX44))
 	s.msg.Header.SetField(tagMsgType, FIXString("A"))