Fix: Text array parsing disambiguates NULL and "NULL".

This solution is a little awkward, but it avoids breaking backwards
compatibility.

fixes #78

aclitem_array.go

@@ -317,7 +317,7 @@ func (dst *ACLItemArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem ACLItem
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

array.go

@@ -82,6 +82,7 @@ func (src ArrayHeader) EncodeBinary(ci *ConnInfo, buf []byte) []byte {
 
 type UntypedTextArray struct {
 	Elements   []string
+	Quoted     []bool
 	Dimensions []ArrayDimension
 }
 
@@ -196,13 +197,14 @@ func ParseUntypedTextArray(src string) (*UntypedTextArray, error) {
 			}
 		default:
 			buf.UnreadRune()
-			value, err := arrayParseValue(buf)
+			value, quoted, err := arrayParseValue(buf)
 			if err != nil {
 				return nil, errors.Errorf("invalid array value: %v", err)
 			}
 			if currentDim == counterDim {
 				implicitDimensions[currentDim].Length++
 			}
+			dst.Quoted = append(dst.Quoted, quoted)
 			dst.Elements = append(dst.Elements, value)
 		}
 
@@ -239,10 +241,10 @@ func skipWhitespace(buf *bytes.Buffer) {
 	}
 }
 
-func arrayParseValue(buf *bytes.Buffer) (string, error) {
+func arrayParseValue(buf *bytes.Buffer) (string, bool, error) {
 	r, _, err := buf.ReadRune()
 	if err != nil {
-		return "", err
+		return "", false, err
 	}
 	if r == '"' {
 		return arrayParseQuotedValue(buf)
@@ -254,41 +256,41 @@ func arrayParseValue(buf *bytes.Buffer) (string, error) {
 	for {
 		r, _, err := buf.ReadRune()
 		if err != nil {
-			return "", err
+			return "", false, err
 		}
 
 		switch r {
 		case ',', '}':
 			buf.UnreadRune()
-			return s.String(), nil
+			return s.String(), false, nil
 		}
 
 		s.WriteRune(r)
 	}
 }
 
-func arrayParseQuotedValue(buf *bytes.Buffer) (string, error) {
+func arrayParseQuotedValue(buf *bytes.Buffer) (string, bool, error) {
 	s := &bytes.Buffer{}
 
 	for {
 		r, _, err := buf.ReadRune()
 		if err != nil {
-			return "", err
+			return "", false, err
 		}
 
 		switch r {
 		case '\\':
 			r, _, err = buf.ReadRune()
 			if err != nil {
-				return "", err
+				return "", false, err
 			}
 		case '"':
 			r, _, err = buf.ReadRune()
 			if err != nil {
-				return "", err
+				return "", false, err
 			}
 			buf.UnreadRune()
-			return s.String(), nil
+			return s.String(), true, nil
 		}
 		s.WriteRune(r)
 	}

array_test.go

@@ -16,6 +16,7 @@ func TestParseUntypedTextArray(t *testing.T) {
 			source: "{}",
 			result: pgtype.UntypedTextArray{
 				Elements:   nil,
+				Quoted:     nil,
 				Dimensions: nil,
 			},
 		},
@@ -23,6 +24,7 @@ func TestParseUntypedTextArray(t *testing.T) {
 			source: "{1}",
 			result: pgtype.UntypedTextArray{
 				Elements:   []string{"1"},
+				Quoted:     []bool{false},
 				Dimensions: []pgtype.ArrayDimension{{Length: 1, LowerBound: 1}},
 			},
 		},
@@ -30,6 +32,7 @@ func TestParseUntypedTextArray(t *testing.T) {
 			source: "{a,b}",
 			result: pgtype.UntypedTextArray{
 				Elements:   []string{"a", "b"},
+				Quoted:     []bool{false, false},
 				Dimensions: []pgtype.ArrayDimension{{Length: 2, LowerBound: 1}},
 			},
 		},
@@ -37,6 +40,7 @@ func TestParseUntypedTextArray(t *testing.T) {
 			source: `{"NULL"}`,
 			result: pgtype.UntypedTextArray{
 				Elements:   []string{"NULL"},
+				Quoted:     []bool{true},
 				Dimensions: []pgtype.ArrayDimension{{Length: 1, LowerBound: 1}},
 			},
 		},
@@ -44,6 +48,7 @@ func TestParseUntypedTextArray(t *testing.T) {
 			source: `{""}`,
 			result: pgtype.UntypedTextArray{
 				Elements:   []string{""},
+				Quoted:     []bool{true},
 				Dimensions: []pgtype.ArrayDimension{{Length: 1, LowerBound: 1}},
 			},
 		},
@@ -51,6 +56,7 @@ func TestParseUntypedTextArray(t *testing.T) {
 			source: `{"He said, \"Hello.\""}`,
 			result: pgtype.UntypedTextArray{
 				Elements:   []string{`He said, "Hello."`},
+				Quoted:     []bool{true},
 				Dimensions: []pgtype.ArrayDimension{{Length: 1, LowerBound: 1}},
 			},
 		},
@@ -58,6 +64,7 @@ func TestParseUntypedTextArray(t *testing.T) {
 			source: "{{a,b},{c,d},{e,f}}",
 			result: pgtype.UntypedTextArray{
 				Elements:   []string{"a", "b", "c", "d", "e", "f"},
+				Quoted:     []bool{false, false, false, false, false, false},
 				Dimensions: []pgtype.ArrayDimension{{Length: 3, LowerBound: 1}, {Length: 2, LowerBound: 1}},
 			},
 		},
@@ -65,6 +72,7 @@ func TestParseUntypedTextArray(t *testing.T) {
 			source: "{{{a,b},{c,d},{e,f}},{{a,b},{c,d},{e,f}}}",
 			result: pgtype.UntypedTextArray{
 				Elements: []string{"a", "b", "c", "d", "e", "f", "a", "b", "c", "d", "e", "f"},
+				Quoted:   []bool{false, false, false, false, false, false, false, false, false, false, false, false},
 				Dimensions: []pgtype.ArrayDimension{
 					{Length: 2, LowerBound: 1},
 					{Length: 3, LowerBound: 1},
@@ -76,6 +84,7 @@ func TestParseUntypedTextArray(t *testing.T) {
 			source: "[4:4]={1}",
 			result: pgtype.UntypedTextArray{
 				Elements:   []string{"1"},
+				Quoted:     []bool{false},
 				Dimensions: []pgtype.ArrayDimension{{Length: 1, LowerBound: 4}},
 			},
 		},
@@ -83,6 +92,7 @@ func TestParseUntypedTextArray(t *testing.T) {
 			source: "[4:5][2:3]={{a,b},{c,d}}",
 			result: pgtype.UntypedTextArray{
 				Elements: []string{"a", "b", "c", "d"},
+				Quoted:   []bool{false, false, false, false},
 				Dimensions: []pgtype.ArrayDimension{
 					{Length: 2, LowerBound: 4},
 					{Length: 2, LowerBound: 2},

bool_array.go

@@ -319,7 +319,7 @@ func (dst *BoolArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Bool
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

bpchar_array.go

@@ -319,7 +319,7 @@ func (dst *BPCharArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem BPChar
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

bytea_array.go

@@ -291,7 +291,7 @@ func (dst *ByteaArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Bytea
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

cidr_array.go

@@ -348,7 +348,7 @@ func (dst *CIDRArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem CIDR
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

date_array.go

@@ -320,7 +320,7 @@ func (dst *DateArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Date
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

enum_array.go

@@ -317,7 +317,7 @@ func (dst *EnumArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem GenericText
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

float4_array.go

@@ -319,7 +319,7 @@ func (dst *Float4Array) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Float4
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

float8_array.go

@@ -319,7 +319,7 @@ func (dst *Float8Array) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Float8
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

hstore_array.go

@@ -291,7 +291,7 @@ func (dst *HstoreArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Hstore
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

inet_array.go

@@ -348,7 +348,7 @@ func (dst *InetArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Inet
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

int2_array.go

@@ -711,7 +711,7 @@ func (dst *Int2Array) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Int2
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

int4_array.go

@@ -711,7 +711,7 @@ func (dst *Int4Array) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Int4
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

int8_array.go

@@ -711,7 +711,7 @@ func (dst *Int8Array) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Int8
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

jsonb_array.go

@@ -319,7 +319,7 @@ func (dst *JSONBArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem JSONB
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

macaddr_array.go

@@ -320,7 +320,7 @@ func (dst *MacaddrArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Macaddr
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

numeric_array.go

@@ -487,7 +487,7 @@ func (dst *NumericArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Numeric
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

text_array.go

@@ -319,7 +319,7 @@ func (dst *TextArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Text
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

text_array_test.go

@@ -6,8 +6,20 @@ import (
 
 	"github.com/jackc/pgtype"
 	"github.com/jackc/pgtype/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
+// https://github.com/jackc/pgtype/issues/78
+func TestTextArrayDecodeTextNull(t *testing.T) {
+	textArray := &pgtype.TextArray{}
+	err := textArray.DecodeText(nil, []byte(`{abc,"NULL",NULL,def}`))
+	require.NoError(t, err)
+	require.Len(t, textArray.Elements, 4)
+	assert.Equal(t, pgtype.Present, textArray.Elements[1].Status)
+	assert.Equal(t, pgtype.Null, textArray.Elements[2].Status)
+}
+
 func TestTextArrayTranscode(t *testing.T) {
 	testutil.TestSuccessfulTranscode(t, "text[]", []interface{}{
 		&pgtype.TextArray{

timestamp_array.go

@@ -320,7 +320,7 @@ func (dst *TimestampArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Timestamp
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

timestamptz_array.go

@@ -320,7 +320,7 @@ func (dst *TimestamptzArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Timestamptz
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

tstzrange_array.go

@@ -272,7 +272,7 @@ func (dst *TstzrangeArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Tstzrange
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

typed_array.go.erb

@@ -292,7 +292,7 @@ func (dst *<%= pgtype_array_type %>) DecodeText(ci *ConnInfo, src []byte) error
 		for i, s := range uta.Elements {
 			var elem <%= pgtype_element_type %>
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

uuid_array.go

@@ -375,7 +375,7 @@ func (dst *UUIDArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem UUID
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)

varchar_array.go

@@ -319,7 +319,7 @@ func (dst *VarcharArray) DecodeText(ci *ConnInfo, src []byte) error {
 		for i, s := range uta.Elements {
 			var elem Varchar
 			var elemSrc []byte
-			if s != "NULL" {
+			if s != "NULL" || uta.Quoted[i] {
 				elemSrc = []byte(s)
 			}
 			err = elem.DecodeText(ci, elemSrc)