CASSGO-98 Do not set compression flag in a frame header when native proto v5 is being used

Previously, during frame construction the driver was setting frame compression flag for each individual frame if a compressor is set in the ClusterConfig. However, for the Native Protocol 5 version the compression flag is deprecated. While Cassandra 4.0 just ignores this flag, some other third-party applications, that rely on v5 proto, could experience errors as the body of the frame is not actually compressed.

Now it adds the compression flag only if the compressor is set and proto version < 5.

Patch by Bohdan Siryk; Reviewed <> for CASSGO-98

Author: worryg0d

frame.go

@@ -393,7 +393,7 @@ func newFramer(compressor Compressor, version byte, r *RegisteredTypes) *framer
 		types:      r,
 	}
 	var flags byte
-	if compressor != nil {
+	if compressor != nil && version < protoVersion5 {
 		flags |= flagCompress
 	}
 

frame_test.go

@@ -34,6 +34,8 @@ import (
 	"reflect"
 	"testing"
 
+	"github.com/apache/cassandra-gocql-driver/v2/lz4"
+	"github.com/apache/cassandra-gocql-driver/v2/snappy"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -836,3 +838,58 @@ func BenchmarkFramerReadCol_Set(b *testing.B) {
 		_ = framer.readCol(&col, nil, true, "", "")
 	}
 }
+
+func Test_newFrame_compressionFlag(t *testing.T) {
+	tests := []struct {
+		name          string
+		protoVersion  protoVersion
+		compressor    Compressor
+		expectedFlags byte
+	}{
+		{
+			name:          "proto3-nil-compressor",
+			protoVersion:  protoVersion3,
+			compressor:    nil,
+			expectedFlags: 0, // no flags
+		},
+		{
+			name:          "proto3-snappy-compressor",
+			protoVersion:  protoVersion3,
+			compressor:    snappy.SnappyCompressor{},
+			expectedFlags: 0b1, // compressions is enabled
+		},
+		{
+			name:          "proto4-nil-compressor",
+			protoVersion:  protoVersion4,
+			compressor:    nil,
+			expectedFlags: 0,
+		},
+		{
+			name:          "proto4-snappy-compressor",
+			protoVersion:  protoVersion4,
+			compressor:    snappy.SnappyCompressor{},
+			expectedFlags: 0b1,
+		},
+		{
+			name:          "proto5-nil-compressor",
+			protoVersion:  protoVersion5,
+			compressor:    nil,
+			expectedFlags: 0,
+		},
+		{
+			// In protocol v5 compression happens on the segment level (v5 new frame format). The body of the frame (envelope)
+			// is not compressed, so we don't have to set compression flag in the frame header
+			name:          "proto5-lz4-compressor-no-compression-flag",
+			protoVersion:  protoVersion5,
+			compressor:    lz4.LZ4Compressor{},
+			expectedFlags: 0,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			f := newFramer(test.compressor, byte(test.protoVersion), GlobalTypes)
+			require.Equal(t, test.expectedFlags, f.flags)
+		})
+	}
+}