fix null deserialization issues

converter.go

@@ -632,12 +632,20 @@ func arrowToValue(
 		case arrow.INT32:
 			values := vectorData.ListValues().(*array.Int32).Int32Values()
 			for i := 0; i < vectorData.Len(); i++ {
-				destcol[i] = values[i*dim : (i+1)*dim]
+				if vectorData.IsNull(i) {
+					destcol[i] = []int32(nil)
+				} else {
+					destcol[i] = values[i*dim : (i+1)*dim]
+				}
 			}
 		case arrow.FLOAT32:
 			values := vectorData.ListValues().(*array.Float32).Float32Values()
 			for i := 0; i < vectorData.Len(); i++ {
-				destcol[i] = values[i*dim : (i+1)*dim]
+				if vectorData.IsNull(i) {
+					destcol[i] = []float32(nil)
+				} else {
+					destcol[i] = values[i*dim : (i+1)*dim]
+				}
 			}
 		default:
 			return fmt.Errorf("unsupported element type %q for a vector", datatype.Elem().String())

converter_test.go

@@ -857,14 +857,15 @@ func TestArrowToValue(t *testing.T) {
 		},
 		{
 			logical: "vector",
-			values:  [][]int32{{1, 2, 3}, {4, 5, 6}},
+			values:  [][]int32{nil, {1, 2, 3}},
 			builder: array.NewFixedSizeListBuilder(pool, 3, &arrow.Int32Type{}),
 			append: func(b array.Builder, vs interface{}) {
 				for _, v := range vs.([][]int32) {
 					lb := b.(*array.FixedSizeListBuilder)
 					vb := lb.ValueBuilder().(*array.Int32Builder)
 					if len(v) == 0 {
 						lb.AppendNull()
+						vb.AppendValues([]int32{-1, -1, -1}, nil)
 						continue
 					}
 
@@ -885,14 +886,15 @@ func TestArrowToValue(t *testing.T) {
 		},
 		{
 			logical: "vector",
-			values:  [][]float32{{1.1, 2.2, 3}, {4.4, 5.5, 6}},
+			values:  [][]float32{nil, {1.1, 2.2, 3}},
 			builder: array.NewFixedSizeListBuilder(pool, 3, &arrow.Float32Type{}),
 			append: func(b array.Builder, vs interface{}) {
 				for _, v := range vs.([][]float32) {
 					lb := b.(*array.FixedSizeListBuilder)
 					vb := lb.ValueBuilder().(*array.Float32Builder)
 					if len(v) == 0 {
 						lb.AppendNull()
+						vb.AppendValues([]float32{-1, -1, -1}, nil)
 						continue
 					}