Merge pull request #70392 from cockroachdb/blathers/backport-release-…

…21.2-70375

release-21.2: sql: preserve tuple types when decoding

pkg/sql/colencoding/value_encoding_test.go

@@ -11,7 +11,6 @@
 package colencoding
 
 import (
-	"fmt"
 	"testing"
 
 	"github.com/cockroachdb/cockroach/pkg/col/coldata"
@@ -40,7 +39,6 @@ func TestDecodeTableValueToCol(t *testing.T) {
 		typs[i] = ct
 		datums[i] = datum
 		var err error
-		fmt.Println(datum)
 		buf, err = rowenc.EncodeTableValue(buf, descpb.ColumnID(encoding.NoColumnID), datum, scratch)
 		if err != nil {
 			t.Fatal(err)
@@ -49,7 +47,6 @@ func TestDecodeTableValueToCol(t *testing.T) {
 	batch := coldata.NewMemBatchWithCapacity(typs, 1 /* capacity */, coldataext.NewExtendedColumnFactory(nil /*evalCtx */))
 	for i := 0; i < nCols; i++ {
 		typeOffset, dataOffset, _, typ, err := encoding.DecodeValueTag(buf)
-		fmt.Println(typ)
 		if err != nil {
 			t.Fatal(err)
 		}

pkg/sql/rowenc/column_type_encoding.go

@@ -1072,10 +1072,8 @@ func decodeTuple(a *DatumAlloc, tupTyp *types.T, b []byte) (tree.Datum, []byte,
 		return nil, nil, err
 	}
 
-	result := tree.DTuple{
-		D: a.NewDatums(len(tupTyp.TupleContents())),
-	}
-
+	result := *(tree.NewDTuple(tupTyp))
+	result.D = a.NewDatums(len(tupTyp.TupleContents()))
 	var datum tree.Datum
 	for i := range tupTyp.TupleContents() {
 		datum, b, err = DecodeTableValue(a, tupTyp.TupleContents()[i], b)

pkg/sql/rowenc/column_type_encoding_test.go

@@ -338,3 +338,22 @@ func TestDecodeTableValueOutOfRangeTimestamp(t *testing.T) {
 		})
 	}
 }
+
+// This test ensures that decoding a tuple value with a specific, labeled tuple
+// type preserves the labels.
+func TestDecodeTupleValueWithType(t *testing.T) {
+	tupleType := types.MakeLabeledTuple([]*types.T{types.Int, types.String}, []string{"a", "b"})
+	datum := tree.NewDTuple(tupleType, tree.NewDInt(tree.DInt(1)), tree.NewDString("foo"))
+	buf, err := rowenc.EncodeTableValue(nil, descpb.ColumnID(encoding.NoColumnID), datum, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	da := rowenc.DatumAlloc{}
+	var decoded tree.Datum
+	decoded, _, err = rowenc.DecodeTableValue(&da, tupleType, buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	require.Equal(t, decoded, datum)
+}